I bought an '07 Impala LTZ in October. I noticed right away when driving at night that the instrument panel lights and the headlights would dim down and then go back to normal as I was driving. This happens all the time. Have had the car into the dealer and they have seen the problem, but have now way to fix. GM engineering has said there is no fix at this time. Has anyone else had this problem.

I too have a 2007 LTZ and am having the same problem. This is due to the 3.9L shutting down 3 cylinders. When this happens, the belt tension is reduced. To maintain proper belt tension, chevy installed a clutch coupling device on the alternator pulley. Now, the alternator couples/decouples from the drivebelt resulting in varying output, and an increase/decrease in voltage. I was just going to take mine to the dealer to see if they have a fix. On a long trip, however I decided to forgo the cruise control and use my foot to keep it in 3 cyl mode. At higher speeds, 75mph, everything is spinning fast enough that the alternator stays engaged and my lights didnt flicker. Once you go back to v6 mode, this problem doesnt occur. let me know if you have any luck getting this problem fixed!!

I, too, have an 07LTZ. This problem happens all the time and I was hoping it was not just my car. I am at least glad to see there are others with this problem. I do quite a bit of highway driving in the evening with the lights on, obviously, and it is usually in the three cylinder mode while doing so. Why would the lights constantly flicker? Is the clutch engaging and dis-engaging all the time? It does seem to happen at shift points, so that would make sense. However, the car should have enough power, regardless, to maintain a steady beam with the headlights and the dash lights. I will pay attention to it and see if it happens only in the 3cylinder mode, or if it does it in both modes and get back to everyone. I am taking mine in for its first service this weekend: lube, tighten the bolts, etc..and I will ask them to take a look and see what they think.

Just as info, I have a 06 SS with the V-8 that goes to 4 cyl. when all 8 are not needed and have not had the problem you mentioned and have not heard of anybody else with the SS having the problem. I appears there is something wrong with the V-6 to 3 cyl. application. I wonder if there is something in the electronics that when the system goes to 3 cyl. mode there is a parasitic electrical draw on the system causing the dim lights. Could be a short in one of the relays.

I have a 2007 LTZ as well, I have the same problem as described by chevy038.....

Anyone have any updates as what their dealers says in regards to the problem? It truly is a abnormal issue.... You think after making cars for 100 years we would have headlights that wouldn't flicker....

I hadn't made a payment on my car when I took it in for this problem. They had it a week and a half and finally seen the problem. The service manager told me that they were told that there was no fix at this time and to give me the car back. Their tac people told the service techs to say that it's normal for this to happen. The service manager drives an 07 LTZ and didn't notice his doing the same thing till he drove mine. Whenever this happens to mine, the compass locks up also. So far on this car I've had to have the tires balanced the day after I picked it up new, trouble with the lights flickering, the day I picked it up after they had it a week and a half for the light problem, I got home and there was a letter informing me that there was a recall on the gas tank. Also, when the weather gets colder, the remote start doesn't work like it should, you have to be on top the car for it to work. They told me that there is to be a recall on the remote start antenna, they should have announced it already, but don't have the parts yet. Now the auto lights won't go out when it's bright outside. They know about the light problem and some of the others. The service manager took me in the back and showed me the web site that the techs go to and there were two messages that morning about the problem. Even the service techs said that the problem wasn't right. The last three out of four cars I bought were new GM products, 1 Oldsmobile, 1 Pontiac Grand Prix, 1 Chevy LTZ and I've had major problems with all three. I have told them at the dealership that I will give them a reasonable amount of time to fix the problems and if not fixed correctly, I am going to get rid of the vehicle and go right to the Nissan dealership. Maybe they can make a vehicle that works right some of the time.

I know there is a lot of frustration here, and heck, I am too! I just bought this puppy and this flickering thing is really annoying. But I've been doing my research on this issue, and I've got a master's degree in mechanical engineering and I still got my 2007 LTZ. If i felt it was a bad car, I wouldnt have put my hard earned money on it. The whole issue just started for the 2007 model year, which, is only a couple of monthes old. My 2007 was one of the first ones and I got it in October. This all just started with '07 because of the new active feul management for the 3.9L v6. Last year's 3.9L didnt have this feature, so no alternator clutch issues. currently, the 2007 Impala 3LT and LTZ are the only 2 trims that have this...and the 3.9L only comprises 25% of all Impalas. GM is JUST starting to get a trickle of word on this problem, because there are just so few of this specific cars/models/engines/year on the road just yet. Everyone should talk to GM about this. Going to a dealer, even if they replace the alternator, it's not gonna fix the problem. They need a revised alternator clutch assembly and/or belt tensioner. As far as for now...the clutch deal only works when the engine is in 3 cyl mode, and is below 2000 rpms. Like I said before, when i'm cruising at 75 mph its spinning at 2300 rpm and the clutch is totally locked up and my lights are steady. Also, I found that if I run with my fog lights on too, it seems to improve the situation. Maybe the added electrical load of the fog lights keeps the alternator engaged more. Everyone should post any other info/websites are dealer resposes on this page. Hopefully I can get this fixed, and i too have the remote start antenna prob, then my LTZ will be PERFECT. By the way, the gas tank recall only affected all of 14 cars total...

I hadn't made a payment on my car when I took it in for this problem. They had it a week and a half and finally seen the problem. The service manager told me that they were told that there was no fix at this time and to give me the car back. Their tac people told the service techs to say that it's normal for this to happen. The service manager drives an 07 LTZ and didn't notice his doing the same thing till he drove mine. Whenever this happens to mine, the compass (http://www.chevroletforum.com/m_14655/tm.htm#) locks up also. So far on this car I've had to have the tires balanced the day after I picked it up new, trouble with the lights flickering, the day I picked it up after they had it a week and a half for the light problem, I got home and there was a letter informing me that there was a recall on the gas tank. Also, when the weather gets colder, the remote start doesn't work like it should, you have to be on top the car for it to work. They told me that there is to be a recall on the remote start antenna, they should have announced it already, but don't have the parts yet. Now the auto lights won't go out when it's bright outside. They know about the light problem and some of the others. The service manager took me in the back and showed me the web site that the techs go to and there were two messages that morning about the problem. Even the service techs said that the problem wasn't right. The last three out of four cars I bought were new GM products, 1 Oldsmobile, 1 Pontiac Grand Prix, 1 Chevy LTZ and I've had major problems with all three. I have told them at the dealership that I will give them a reasonable amount of time to fix the problems and if not fixed correctly, I am going to get rid of the vehicle and go right to the Nissan dealership. Maybe they can make a vehicle that works right some of the time.
If you haven't called the GM hotline on this problem, call them. The more complaints the better and they will have to find a fix quicker. My service manager told me to call and complain and that they will call him and he can tell them also.

whats the number?

The phone number is on page 428 of your owners manual, but here it is also- Chevrolet Customer Assistance Center- 1-800-222-1020. Another phone number for the assistance center that was on my recall notice is 1-800-630-2438. My dealership service department has done everything they can, but they can't fix something they don't know what's causing the problem. I blame GM for this.

I drive my car at night with the instrument panel lights turned down some and my fog lights on. It's kind of an optical illusion, I don't notice the lights pulsing as much. My service manager said the only time he noticed his lights flickering was when he had his fog lights on and he suggested that I drive without them on. I have tried some experiments. One night I turned everything off except the headlights. No radio, heater, fog lightsor anything else that I could shut off. The lights still flickered. I regularly drive 75 or 80 mph on I-65 and the lights still flicker. It is correct that they are flickering when I'm in the 3 cylinder mode. When I hit the gas, the lights stay bright. Some times they are worse than others, last night they were so bad that I could see them pulse over the fog lights. Hope that this doesn't happen to somebody with epilepsy, might trigger a siezure.

PS
Have your vin # handy, am told that they will ask for it.

I was experimenting and found that if you drive the car in 3 instead of Drive mode that it locks the car in 6 cylinder mode and the lights won't flicker. The only thing that this will affect is your gas mileage. I drive my car in 3 at night and in Drive in the daytime. If your lights flickering bothers you like it does me, this might keep you from going crazy till they find out how to fix it.

I just purchased an 07 Impala with the 3.9 engine. My lights flicker and the mileage display goes off and comes back on. After two tries the dealer gave me a form that said GM is aware of the problem but has no clue how to fix it.And there will probably be no recall if they discover a solution. It is really frustation to buy a new car and drive down the road with yuor lights blinking off and on.

BobbyJo

I have just come from my dealer. My service manager called me the other day and told me that they have a temporary fix and will fix it permanately when they get the correct parts. Call your service department and tell them to get a hold of their factory rep and he should be able to tell them what to do to fix the problem. They have to do something with the alternator. It took them approx. 20 minutes to do the proceedure. Was also told that the recall for the remote start should start in about ten days. Don't know if the fix works till I go to work tonight, but they say it will. Keep fingers crossed.

had this happen to a customer with his 06 Impala, Tech found a loose ground wire on the back of his headlight somewhere....fixed the problem in about 10 seconds...not sure that is EVERYONEs problem but may fix a couple of u guys

This is a problem with just the '07s, has to do with the engine going from six to three cylinders. Temp fix seems to be working so far on my car.

EXCELLENT!! So I called GM to report this problem, and the rep said they are not aware of it. The dealer told me that this is normal. Do you have a copy of your warranty repair from your dealer on what they did to fix this prob? Now it seems that a fix is here, and I'm hitting a dead end. congrats on GM getting their act together. Once I get my headlights and remote start probs fixed, my car will be perfect!!

Sorry to give you the bad news, but fix worked for a short time and then went back to the same thing. Talked to my service manager this morning and he couldn't understand why it's doing what it is, but they are working on it and should have a fix shortly. They know what's causing it, but don't know exactly how to fix it. Sorry for the false info.
On another note, got a call today that they have the parts in for the remote start and I have an appointment for Monday for my car to go under the knife. I am the first one in this area (Northwest Indiana) Wish me luck.

man, close but no cigar! Good news on the antenna fix. SO what exactly is causing this irratic voltage issue? was it the alternator like I suspected?

From what I understand, the alternator changes it's output according to how you drive and whether it's in 6 or three cylinder mode. The temp fix was that they made the alternator put out full voltage all the time like it was in 6 cylinder mode all the time. Thought it worked, but then had to go on the Interstate and they started pulsing again. Like I said, when I drive in 3 instead of Drive, it locks in 6 cylinder mode and the lights don't pulse. They are working on this and should have a fix soon, but not soon enough for me. At least the remote start will work without me sitting in the car to use it.

I just spent about 45 minutes on the phone with G.M. A lot of questions and no answers. They seemed to act like I was the first person to call and complain about the lights. I tried to drive in 3 instead of D and it seemed to help a little. It doesn't hurt the car to drive in 3 on the interstate?It is very frustating to drive at night and your lights flicker. Several times my display went completely out.Several cars in front of me think I am asking them to get outof my way and pull to the next lane. I sure hope GM comes up with a solution but I have my doubts.

Definitely sounds like an issue with the Regulated Voltage Control ( RVC) system. It may be a software issue that they're trying to correct.

Only thing that will take a hit is your gas mileage. I asked the same question of my service manager. I also spent a lot of time on the phone. The woman I talked to at the TAC center kind of got me angry when she said to me that if there is no fix for my car, what do I want. I proceeded to tell her in no uncertain terms. They do know about the problem and are working on it. The temporary fix they tried on my car didn't work, so it's back to the drawing board. If you are having trouble with your remote start, keyless entry, or the service tire pressure system comes on, call your dealer and hound them to get the parts to fix this problem. I had mine done today and it works better than when I first got the car. They are getting the parts, but your dealer has to order them. It took about three days for my dealer to get my parts. I have a good relationship with my service writer and service manager and they tell me about new info as soon as it becomes available to them. Will pass on whatever I find out as soon as possible.

Just came back from my dealer today about my headlights and the remote start/tire pressure issue. They start a service claim from chevy, and spoke with them directly, and said there is a service bulletin out for the active fuel manegment. Then, moving onto the remote start issue, the latest TSB said to order new remote controls, then reprogram the reciever. How is a new remote going to fix the tire monitors? Shouldnt they replace them too? I dont get them! Maybe the reprogramming will do the trick but from what i have heard, a new reciever/antenna in the vehicle is the solution. That makes more sense. Exactly what parts did they get for your vehicle?? As soon as the remotes are in, I'll be back to them and hopefully they will have something back from GM. P.S: driving in 3 instead of D is a lot of wear and tear on your car. The engine is probably screaming at 3500 rpm on the highway in that gear. I wouldnt do it.

They gave me two new remote transmitters, replaced the antennae and the reciever under the dash. There is supposed to be a recall coming out soon. Like I said, my service writer is a great lady and she ordered the parts for me as soon as they became available. Just reprograming the old reciever won't fix anything. Have your service manager call up document #1875244 and show you what this is about. There's six things that this affects.

These are the part numbers for what they put in my car, 1- antenna, part #25837954 1-receiver, part #15946938 2-transmitters, part # 15912860. Maybe this will help you get something fixed on your car. Let me know what they say.

there is already a thread started about the transmitter and the remote start, please use that. I took my car into the dealer for the second time yesterday and they talked to engineering and the factory rep. There is now a TSB out about this problem with number PIC4354B, or at least that is what it says on my printout. They unhooked the 'battery current sensor' and said that this is the temp. fix until Chevy can come up with something better. He said they are working on it and all they can do right now is unhook that particular sensor. I don't know if it really helped or not, the lights seemed to pulse this morning, but maybe I was being too sensitive to them. I will have to drive it more at night to really make sure they are not pulsing anymore.

Just had a long day at the dealer yesterday, they replaced my transmitters and antenna. The remote start is STILL the way it is...even after this "new fix"!! ANd to top that off, they put things back together wrong, and I have a huge gap between my A pillar and dashboard. For the flickering, they do have a PI notice out, they are aware of it, but they have yet to find the cause...let alone find a solution. I was told by my dealer to sit tight and wiat. I'm not happy!!

I think that you need to go to a different dealer/sevice department. They have to replace the receiver also. I put the part numbers in one of my answers. My remote works great. We walked it off the other day and it was close to three hundred feet. After reading your note, I checked my car and it looks like it did when I bought it. The service tech that did mine was an older guy, one with a lot of experience, another assist by my service adviser. Like I said a great lady. Don't know where you live, but my service department has updated service bullitens. As you said though, there is no fix for the flickering lights at this time. The TAC rep is supposed to call me Thursday and let me know what if any progress is being made on this problem. I'd get on my service department if I was you. Sounds like they're giving you the run around.

can someone describe how noticeable this is?

It can vary. When I first bought my car, I noticed it right away, but it wasn't real noticable. I waited about a week to make sure that it wasn't just me. It has gotten worse though. It will happen only when the engine is running in three cylinder mode. At first I was able to turn the fog lights on so I wouldn't notice it so much, but now I can see the pulsing of the lights over the fog lights. I found out that if I drove in 3 instead of drive, it locks the car in six cylinder mode and the lights don't flicker. The little worse gas mileage doesn't bother me as much as the lights pulsing. As of now, there is no fix. They tried a temp fix, but it didn't work.

Well, like ohseven said, my temporary fix did not work. The lights are still flickering like they used to. I will call my service guy today and give him the bad news :-( I bought my car at probably the biggest Chevy dealer here in Indianapolis. They seem pretty confident and knowledgable (sp?) about what they are doing, but this car has a lot of quirks that drive me batty! Like this morning itwas VERY cold out. My gauge on the car read -4F. Then my warning thing started going off telling me my tire pressure is low and the dash light came on. I got out and looked at the tired and they seemed fine to me. I think with the extremely cold air the sensor may not work correctly. Plus, the air inside the tires loses pressure when its so cold out. On the drive to work they gained an extra 4 pounds all around, just from heating up with the road friction, etc. Does anyone else notice this problem? This car seems to have a few too many "quirks" for my liking right now.

Im not at all surprissed with warning regarding the low air. If youre in an area that gets fairly cold- then this would not concern me.
so your low pressure warning went away once the tire warmed up?

Same thing happened with my car this morning. Was -9° this morning and my tire pressure warning was going off. Said the tires were about 24#s each. Went off at 27#. Going to check and add some later this evening when they cool off again. Guess it's normal in this weather.

Totally normal thing to happen. We are just seeing this now because these cars are equipped with realtime tire monitoring. When it's -9 out, i'm not gogin to be running around my car with a tire pressure guage. Every 10 degrees of temp drop equals 1 psi of pressure.

I have a 2007 3 LT I bought in December. I noticed the light flickering problem right away. I talked to service and the tech said this is normal? I called GM customer service and the rep I spoke with said they are not aware of the problem or any bulletins on it. At least it is a relief to see others have the same problem. Does anyone have an update on a fix?

I have not heard anything lately. from stuff Ive read- seems that GM was working on it.
Now, we did order an 07 3LT. Should arrive in early March.
When we get it, well see if we notice any of this flicker.
I would guess that if a fix is made. they would apply it to the line of new cars?

:)I madea visit to another Cheverolet dealership and asked the service manager about the light problem. He told me GM is telling the dealers to tell the complaining customer the flickering lights on the 3.9 engine are normal and nothing can be done. That makes me feel great.http://www.chevroletforum.com/micons/m7.gif

After reading from this site to my GM contact, hefinally admitted there was a problem, but said since it was not a "safety" issue GM is not doing anything about it! I don't know what the cutoff point is when they will fix a defect ona $30,000 new vehicle!This is my 7th and LAST, purchase of a NEW GM vehicle. It is amazing that the GM execs sit in their ivory towers wondering why Americans are buying Hondas.

From what I was told, (my dealer called chevy tech services directly last week) no fix is out yet. But hopefully there will be! There is a TSB w/ the NHTSA about this:
EXTERIOR LIGHTING:HEADLIGHTS
TSB #4354 -- HEADLAMP FLICKER AND INTERIOR LAMP FLICKER. *KB (NHTSA ID #10020849, no date provided)
somebody should look this thing up! Also, I just looked on mygmlink.com and found that I have a recall on my vehicle, #07007...wonder what that is for!? I have found that this issue is linked to engine load, so when it switches over to 3 cyl and it starts flickering, I back my foot off the gas and really feather it out for a moment and the lights will steady out, then i can ease into the gas like normal and I can stay in 3 cyl mode and my lights are on steady.

Doesthis problemhappen onlyat freeway speeds?

I have been looking very closely for this. So far
I have only been on city streets, 35-40mph, watching closely
for any difference when it goes from 6 to 3, headlightsand the
dash lights do not change. My LTZ was made late Dec.06
if that has anything to do with the problem.
Jim

hey guys- my 07 3Lt is on its way- built the week of Feb 19th. Ill keep an eye out to see if this more recent build shows any problems with this...

NOT a safety concern? That is BS! What about my lights flickering so badly that other cars seem to think I am flashing my lights at them? It was so bad the other night I thought all my lights were going out! Mine does it all the time, on the highway, city streets, etc. It seems to do it at shift points, and at engine load, like when it is trying to decide whether or not to go into the 3cyl mode, going uphill, etc. I am not happy with this transmission either...it is very rough when it shifts...especially when it is trying to find that sweet spot where it can drop into 3cyl. Why is this not a5speed car? I think the dropping thecylinders at cruising is a good idea, but they still have a long way to go before it works properly. How often do all of your transmissions/engines drop to the3cyl mode? Mineseems to do it all the time...and I thought it was only supposed to be at cruising speeds. Am I just being paranoid? I love the car, but the sloppy transmission and headlighsare really raining on my parade. This is my first brand new GM...I have been a long time Ford fan,thejury isstill out if I would buy another one.

hmmm, 1st time I hear of a bad tranny on the impala....
well you hear the typical, but 1st I hear of one searching what gear to settle on...
Interesting.
Ive been seeing this type of complaint over on the 07 Camry side.

we got out car on Monday. So far Ive driven it 2 times and drove so that I went into 3 cylinder mode on the street and the road... and Im not seeing any flicker yet....

UPATE: So I took a long drive at night cuz I had to, and I'm just absolutely sick and tired of this problem. It hasnt gotten any worse/better, but I havent noticed it until I spent an hour and a half watching my lights blink over the weekend. SOOOO I called GM customer assistance, which I had done a while back and they looked up my file. this time I demanded to speak with someone who could tell me what was going on, and better yet, WHEN they were gonna have a fix. GM is aware of the problem, and everyone was saying "when there is a fix, your dealer will be contacted" well, WHEN will that be? A month? A YEAR!? I spoke to another rep, then a supervisor who finally escalated the case and is going to contact my regional rep. So, we'll see where this one goes. Finally got my remote start working, and working so well I can shoot my car over 1000 feet!!! Now, if I can drive at night without my passengers asking what the hell is wrong with my brand new car, this car will be perfect. I urge everyone to get on GM's ass about this, and help get a "fix" for this problem out sooner. BTW, rarrios, your lucky your new car isn't doing this, and can you post this over to the naioa foums too?

I went to my dealer last week here in St. Louis and he told me they are no closer to figuring out what is wrong than they were six months ago. He told me they have no clue what is causing the problem. When I called GM for the second time they acted kinda angry when they told me they knew nothing about the lights flickering and I told them my service rep showed me the bulletin not to change antything because it won't fix the problem. They ten said the usual, they are workig on it. I think we are being given the run around.
Bobby

this is retarded. I haven't heard from my "regional rep" yet!! I doubt he'll call, so I won't hold my breathe. Does anyone know how to get in touch with anyone other than the stupid 1-800 customer assistance number? They don't do anything there.

and what about getting a GM engineer on site to take a look at this crap?

Damn, I just typed a whole long reply and I accidentally erased it! [:'(] I will try again here...I called the customer service number again and told them my story...again. I complained about this being a safety concern, a nuisance, and a general annoyance when driving the vehicle. I also told him, mostly for the engineers to hear, that this problem does NOT seem tohappen in vehicles that have the V-8 engines that drop half the cylinders. I have heard from a few SS Impala owners, and we have a fleet of brand new suburbans here at work which I have driven and none of them exhibit the symptoms of the 3.9. Does anyone know if the similar cars to the Impala...Buicks and etc. have the same engine and problem? Are those owners complaining of this problem. Just out of curiousity...what cars are similar to the Impala? Buick Lucerne? Anyway, the customer service guy called my dealership to see if they knew anything he didn't, and then called me back. He said it is a known problem and General Motors is working on it (sounds like a broken record). I told him I know its a known problem because the last time I had it at the dealership they found the TSB about it, and disconnected the battery voltage regulator or whatever it is called, this did nothing to fix the problem FYI. Supposedly, when it was there, they had an engineer from GM to look at the car, but I don't know if this person ever showed up or not. If its a problem on the 3.9, and works on the v-8's, why can't they fix it? Argh.

G.M. must have done something on the recent LTZ's.
My late Dec.06 blt. and rbarrios (http://www.chevroletforum.com/showProfile.asp?memid=6547)Feb blt. appear OK.
And I realy check for this every time I drive at night and the lights
are not flickering.
Jim

yeah like n7jqp said, our 07 built in Feb has not displayed these symptoms.

does somebody know someone who works at a dealership or who has acess to TSB's? The latest TSB's should be checked, or even better yet, Technical Assistance Center (TAC) should be contacted

well, I just got off the phone with the GM custormer service guy. He said that my file is being closed because the problem was not fixed/they could not fix it for me, and that they are going to send me a Better Business Bureou letter in the mail...whatever that means. He did say the problem is still known and they are working on it, but he closed my account because he could not help me the day I called - for the second time! I told him the situation with the later build dates not seeming to have the probem, and he said he could not add that to my complaint, I could call back again, re-open my original complaint, and then add it in. What a bunch of BS, and these are the people who are trying to help us!

Here is another symptom of the lightsI have noticedwith mycar, does it happen with all of your cars that havethe lightproblem? When the car is running and in Park...like when you start it in the morning, when I shift from Park intoReverse and then into Neutral and thenDrive, the lights dim when I move the selector into Reverse on my way to Drive. They go back to normal after a second, but it definately does dim when I shift from Park into Reverse on my way to Drive. Park against a flat surface at night and try it and see if it does the same thing. I am curious to see ifyour carsdo this like mine.

When I talked to the GM support center to an East Indian woman I could hardly understand, I told her that I had the problem and was told by the dealership that there was no fix at this time, she said if there was no fix what did I want. In no uncertain terms I told her I want them to get off their ass and find a fix. I think that I have waited long enough. I don't think that going to the better business bureau will do anything or else they wouldn't be sending you a paper. I am thinking about going to the media. ABC has done things of this sort in the past, maybe if they start getting bad press about the way they are treating their customers,they might start thinking different. Every time I see an ad on TV about the Impala being a reliable vehicle, I get ticked. I have had three out of four of my last vehicles being GM products, but I think this is the last one and I will tell anyone who will listen about the way GM treats their customers. Maybe that's why they were almost bankrupt. Maybe if everyone who has been treated this way called some sort of media and got them to do an article, things might change.

Check and see if your state has a "Lemon Law". My state has one and basically if you have had it in 4 times for the same problem and they will not or can not fix it then you can ask for a full refund on your car less mileage. Keep good records. Google"Lemon Law"and the name of your state.

I have already contacted my state facilities inspector, and I will begin to pursue further action, because now my lights flicker no matter what, and no matter how fast i drive. I used to be able to go 75 mph and the blinking would stop. Now, it flickers no matter what. I am sick of this. But I am curious as to the later built ones which dont seem to have this problem...can someone who doesnt have this problem pop their hood and see if their alternator pulley has a black plastic cover on it? Maybe they got rid of the decoupling device that could be causing this headache

Black cap appears to be nothing more than a pully. I pulled and twisted it and it is solid.

local://upfiles/6621/0C53B2857CF047E9AD611AA5F39DC8E2.jpg

thanks for the info, mine is the same, but if u look on the v8's and the 3.5l in the base models, their pullies don't look like that.

FYI: I just came from another dealership (I'm out of town visiting family for easter) and they didnt have a clue about the issue, and the service advisor looked up all of the current TSB's (ONLY TSB's, not other documents) and found nothing about this problem. So, no update as of today, unless someone can look up PI (preliminary information) documents and see if PIC4354B has been updated/changed, etc. because that is what is currently out about this problem. Thanks guys, and have a Happy Easter!
P.S: I also looked under my hood and that black "cap" protruding from the alternator pulley and it is indeed metal and it is part of the pulley. But if you look closely, there is a small black rubber center cap which isnt shown in the photo, which could be pried off and someone can gain access to the guts inside. If anyone is brave enough, pry off the cover and take a look, I don't know if that cover will be in good enough a shape to be reused afterwards.

I had another look at it as its so tight in there. NowI see
the center rubber insert. I will leave it for some one else
to pry it open.
Here is whats on the back of the unit

Bosch 125
0 124 425 49
14v 65-120A
15 233 597

Must be good as its made in Mexico.

Jim

THEY FIXED IT!!!!!!!!!!!!!!!!!!!!!!!!!!!
Just went into my dealer to raise hell, and the service advisor did one last quick search and found this updated preliminary information:
Headlamp Flicker and Interior Lamp Flicker- #PIC4354D- dated 3/14/07

Condition/Concern:

When driving interior and exterior lamps may flicker on vehicles equipped with the LZ8 3.9L engine.
Headlamps and Interior lamps flicker when switching between 3 and 6 cylinder mode mostly at highway speed.

Recommendation/Instructions:

Engineering has root caused the concern and has validated a repair. A Technical Service Bulletin and updated parts will be released in the near future.

This is a proactive PI. When a TAC case is set and the service repair becomes available your dealer will be sent a DCS message.


I CAN'T WAIT F OR THIS FIX TO COME OUT! EVERYONE SPREAD THE WORD TO ALL THOSE WHO HAVE THIS PROBLEM, AND TO OTHER FORUMS WHERE THIS ISSUE IS BEING DISCUSSED. ALSO, KEEP REPEATEDLY CHECKING THE SERVICE BULLETINS UNTIL THIS FINALLY GETS CORRECTED...

my girlfriends dad sent me this....maybe it is linked to our problem. Did they put the wrong alternator's in our car???






Subject:

Engine Compartment Or Accessory Drive Belt Noise - keywords alternator cylinder deactivation mode pulley #PIP4111 - (04/11/2007)






Models:

2007 Chevrolet Impala or Monte Carlo








Equipped with 3.9L LZ8 Engine (VIN Code R) Active Fuel Management


[hr]
[/align]The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.

Condition/Concern: (http://esiwip.spo.gm.com/servlets/BlobShtml?ShtmlFile=1958515&psdid=0#ss1-1958515ss1-1958515)

Some customers may comment about a noise coming from the engine compartment when traveling at steady speeds. Some may also comment that the noise can only be heard when the engine is operating in the 3 cylinder mode (cylinder deactivation). Upon inspection you may find that the noise is coming from the accessory drive belt and that it appears to be jumping or whipping up and down only when the 3 cylinder mode is activated. When the engine is operating in the 6 cylinder mode the belt movement is smooth and the noise is not present.

Recommendation/Instructions: (http://esiwip.spo.gm.com/servlets/BlobShtml?ShtmlFile=1958515&psdid=0#ss2-1958515ss2-1958515)

Verify that the engine has the correct alternator installed. The alternator used on the 3.9L LZ8 engine (active fuel management) is unique and has a declutching pulley feature which is used with the cylinder deactivation. This alternator is not used on the 3.9L LZ9 engine or the 3.5L LZ4 or LZE engines. See the pictures below for alternator identification.


[/URL]


[URL=http://esiwip.spo.gm.com/servlets/RetrieveTif?pic=1958495] (http://esiwip.spo.gm.com/servlets/RetrieveTif?pic=1958487)
If you find that the vehicle has an incorrect alternator then you must contact Jim Kelly at (586) 492-5612 before replacing it. He will supply you with additional information and also the address of where to send the incorrect alternator to.
Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.






GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.



WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION
© Copyright General Motors Corporation. All Rights Reserved.

could it be some where shipped with the wrong alternator?
good to hear the fix has been found

No, this is if the alternator DOESN'T have that clutch/pulley. But the 3.9L w/ AFM has that odd-looking pulley with a large protrusion coming out of it, which mine has. I dont know if this is linked to our flickering lights, because the PI that I posted yesterday didnt specify what the root cause really is. We'll just have to wait and see...

I called my Service manager and he told me the near future may be 90 days or longer and they are not going to publish the information to the public, so if you don't ask, they won't tell.
Bobby Jo in Missouri

There is a fix now. My Impala '07 had this problem. Went to BBB Auto Complaint Dept. Problem solved on 4/19/07. Replaced Coil Pack and Ground Strap. The reason was they found a failed coil pack. Good luckto everyone getting their problem fixed with what my wife calledour flirting Impala.

WOOO HOO! Hey, did they release a TSB to the dealers? Because I just went to mine on Friday (he checks for bulletins for me twice a week now) and as of 2 days ago he says he didnt find any released bullteins or updated parts. Any info you can give me would be incredibly appreciated, I have had this problem since I got the car in October. Please and thank you!! And by the way...did the fix totally take away all the flickering?

I have been meaning to reply to this thread for a while. I went to my dealer a few weeks ago to get a carwash, and while I was waiting, I started talking to my regular service guy. I showed him the 2 bulletins (above) about the alternator, and the one where engineering found the "root" problem. He called up the service manager (guy in charge of all the regular service guys). He came over and told me that "he talked to engineering yesterday andGM knows about the problem, knows what causes it, but will not fix it." I said, but look at the bulletin...a TSB is coming shortly. He said it isn't, because the fix is too costly for GM. He said its a cost benefit thing, and mentioned that it is perfectly normal for the car to operate like this...all with the smugness of any used car salesman. At that time I wanted to punch that smirk right off of his face! He blamed it on the government and the stringent restrictions they have put on cars to comply with fuel laws or some BS like that. So I said, GM KNOWS about this problem? They are purposely selling faulty cars, and will continue to until they dicontinue the Impala? They are going to put this faulty system in the brand new base Camaro? This makes absolutely no sense to me. He said yes because they are going to do away with the Impala in a few years. I have no idea if this is true or not. He said they are also doing the same thing with the Tahoe which exhibits similar problems. GM refuses to fix our small problem because it is insignificant in their eyes, according to that service manager. Granted, this is what one guy told me and hetold me in the rudest way possible. I seriously wanted to punch him! Why would GM purposely selldefective cars? I see lawsuit written all over that decision...they are already in trouble in terms of sales, why would they risk selling cars like that? Please tell me you guys have heard something different. Keep bugging your service managers, calling the BBB auto line, complaininghere http://www-odi.nhtsa.dot.gov/cars/problems/tsb/tsbsearch.cfm whatever it takes.We know this car is not operating correctly and itneeds to be fixed.

the newer 07's like mine built Feb 12 of 07 does not have this problem. As well as a few other guys with newer build dates and the 3.9 have not seen this problem. Im suspicious of that guys answer.

I agree, I do admit GM sometimes will look the other way on a common problem. And I was worried about this problem being one of those. BUT, the bulletin clearly states a fix is on the way...and someone a few posts ago actually had his car fixed..AND rbarrios's impala doesnt have this problem now.

yah, but like the previous person said, and the service manager said, even though the bulletin says the fix for the problem is coming soon, it could be 9 months or longer...ugh. I will try to follow the route of the coil pack and see if that changes anything.

Is the coil and ground strap supposed to stop the flickering headlight problem? My service rep seemed to think it was to fix a noise problem in the ignition sysytem.

I wonder if Wayne C could give us the specifics of his fix. maybe he wasnt havning the same problem we are talking about. I guess i got my hopes up too soon.

THEY FIXED IT!! THEY FIXED IT!! THEY FIXED IT!!!

I just went to my dealer today to check on things, they said they would call if they found something out, but I decided to check anyways, and it was a good thing!! A full TSB with the fix and new parts is up on the service system dated May 9th. And yes, just as Wayne C said, it is the replacement of the ignition coil and adding a ground strap to the coil. All of the parts are in stock now! Everyone..call your dealers! I have an appointment in two weeks, and I will be the first one they're doing. I guess this settles any doubts of GM fixing their mistakes and hopefully this solves all of my issues with my car. It's been a long six monthes... GM document ID # 1970489

Chev038 let us know if it fixes the problem..........

Well I dropped my car off at the dealer here in Missouri for the coil and ground strap. We will see if it fixes the problem. Has anyone had the repair done and did it fix the problem or is it still there? I will keep my fingers crossed.

Had repair parts put on my car Wednesday, May 30. Drove at highway speeds of 70-75 MPH at night on I-65 in Northwest Indiana and there was no flicker of either the headlights or the instrument panel lights. Made sure that engine kicked down into 3 cylinder mode.It seems that they actually fixed it. Only took eight months, but I guess better late than never.

good news for you guys,

Sorry I never got back to let you folks know about how my fix went, I was out of the coutry for most of the month, and I just moved to a new place and it took 5 days for me to get internet service back up and running, BUT....the good news is...IT'S FIXED!! No more flicker, my car is perfect....spread the word!

Now maybe they can find a fix for the flickering lights on the 02s. Or maybe there is one???????

flickering on 02's?
describe the flicker and conditions.

Headlights flicker most noticeably whenbraking. Have noticed it with steady driving and I always have A/C or defrost on. Dealer always says it's normal. I've never lost lights alltogether. Don't notice dash lights flickering, though. Luckily, I don't do much night driving!!

seems that your lights flickering may be more of a voltage drop when accesories and rear bulbs coming on causing a small drop in voltage.
Have you checked your battery terminals to be sure theyre clean?

They appear to be clean. I'm taking it the shop for other problems, so I'll have them check it out in depth. Thanks!

I just took a trip to Nashville and the lights appear to be working. I believe they finally fixed the light problem,. Hurray I think it is finally fixed.

now that my headlights are fixed, Is anyone having problems with the tire pressure indicator being off. My front tires show proper but the rear tires are way off?

have you reset?

I have reset and put 34 lbs. in the left rear tire according to the gauge and the display still showed 29 lbs.

are you using a good quality gauge? or the ones thats been run over and banged up from the gas station?

ORIGINAL: impalagal

Headlights flicker most noticeably when braking. Have noticed it with steady driving and I always have A/C or defrost on. Dealer always says it's normal. I've never lost lights alltogether. Don't notice dash lights flickering, though. Luckily, I don't do much night driving!!


HI.

I have an O2 Imp LS also and have noticed my head/dash lights will flicker when:

More coasting/no acceleration ~ 30+ mph, RPMs @ 1000~1200. it will do it constatantly too until i change either speed/rpms.

i usually have the radio on too, but i noticed it w/o the radio on. with the winter months here and driving i the dark more, its annoying and im just waiting to get pulled over for it.

i looked at the TSB and it appears that whatever is causing it is alot of other GM products since the problem appears in other makes/models.

any comments/solutions?

sorry to highjack....

I know everybody has said it, so I'll cut right to the chase. Fell in love with my '07 LTZ, thought I was nuts to think that this brand new car could be acting like this, and felt like a goon taking it back for little things like tire pressure system ****. But, alas I do have the flickering headlights, an e-brake that's worthless, and tires that don't know what side of the cars they're on. I'm glad I found this thread and expect to hear from me in the future. On the lighter side of things I've found nothing wrong with the way it drives/handles (except for the lack of a turbo) but I'm sure those are coming in the future.

P.S. anybody fool around with tuning the computer on these things?

the flickering headlight is most likely due to the AFM.
when it goes into 3 cyl mode.
Since you have the LTZ you have the 3.9 L.
There is a fix for that. early build 07's with the 3.9have that issue.
I have an 07 built in February of 07 and it does not have an issue.
YOu probably also had the tire pressure problem and remote with little distance- that is also fixable with a change in the box for the Remote keyless entry.
as for the e-brake.
theyre not longer called emergency brakes for a reason.
theyre now known as Parking brakes.
some lawsuit years ago about an e-brake that didnt stop a car or something- so now its called parking brake.

Just bought an '07 LTZ last week and noticed the instrument lights flickering this evening. I also noticed that the radio is a bit staticky. I'm also getting concerned about the tire pressure monitor now that I'm reading this thread.

I found alist of TSBs at http://www.carcomplaints.com/Chevrolet/Impala/2007/tsbs.shtml (http://www.carcomplaints.com/Chevrolet/Impala/2007/tsbs.shtml). I'm bringing my LTZ back to the dealer this week. On a side note, the dealer told me that the car is certified but I still don't have any paperwork, etc.

Should I have them check everything out and give me a clean bill of health to cover my a** or just have the flicker and tire pressure monitor looked at?

sounds to me like you just need the flicker and tire pressure monitor issues dealt with.
reference the above mentioned TSB's

ORIGINAL: rbarrios

sounds to me like you just need the flicker and tire pressure monitor issues dealt with.
reference the above mentioned TSB's


Just an FYI... the TSB calls for the ignition coil and ground straps to be replaced. Thought that was a little strange.

We have a 2006 Impala LT with the 3500 and it does the same thing with flickering headlights and interior lights. It is very annoying for a new car to do this. Any fixes yet?

I have a 2001 Impala and when it get warm inside (usually after about 15 minutes of driving), then hell breaks loose. The gages die and the headlights and radio go too after flickering for some seconds.


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I also have a 2007 impala with the 3.9, and I have had the same exact problem. I took it to my local Chevy dealer today and told them about the problem. Within 15 seconds, they pulled up the bulletin that was issued to dealers. The fix is to put in a new coil and ground strap. They did this under warranty, and it FIXED the problem. I can now finally drive at night without that annoying flickering. :):):):)


I bought an '07 Impala LTZ in October. I noticed right away when driving at night that the instrument panel lights and the headlights would dim down and then go back to normal as I was driving. This happens all the time. Have had the car into the dealer and they have seen the problem, but have now way to fix. GM engineering has said there is no fix at this time. Has anyone else had this problem.

How many miles do you have on your car GaryS, my 2007 is having this issue also and i have 51,000 on it i just want to see if it is covered under the 100,000 mile warranty or the 36,000 mile warranty