Weird electrical problem
#1
Weird electrical problem
Hey All,
This is my first post here, hopefully future posts will be for solutions instead of problems.
I have a 2002 Silverado 2500 HD with 6.0L gas engine, it only has about 98,000 miles. Recently, it's started doing two things and I don't know if they are related:
1) Threw a P0322 code. This one is pretty straight-forward and the truck does the rough-idle and other things that are called out in the OBD forums. I am planning to replace the knock sensors as advised.
2) This is the weird part:
* Sometimes when I'm driving, the computer resets several times in a row; that is, the radio turns off then on again, the gauges all go to zero then back to correct reading, ABS and brake lights flash, etc. as though I just turned the key on.
* In addition, although this has only happened at idle, sometimes the truck will DIE on the spot and cannot be started again. When this happens, the truck is *completely* dead electrically - door locks don't work, no dome lamp; it's like no battery is installed. I'm not sure what happens, but at some point (usually about 10 minutes or so) it just works again, like nothing was ever wrong.
Is the ECM a goner? What could cause this?
EDIT: More oddity - when the truck is running with no electrical issue, it shows a "check engine". After the truck resets, dies and comes back, check engine is OFF, but it runs WORSE. After a while (a few miles) it will improve and then Check Engine comes back on. Really.
Thanks,
This is my first post here, hopefully future posts will be for solutions instead of problems.
I have a 2002 Silverado 2500 HD with 6.0L gas engine, it only has about 98,000 miles. Recently, it's started doing two things and I don't know if they are related:
1) Threw a P0322 code. This one is pretty straight-forward and the truck does the rough-idle and other things that are called out in the OBD forums. I am planning to replace the knock sensors as advised.
2) This is the weird part:
* Sometimes when I'm driving, the computer resets several times in a row; that is, the radio turns off then on again, the gauges all go to zero then back to correct reading, ABS and brake lights flash, etc. as though I just turned the key on.
* In addition, although this has only happened at idle, sometimes the truck will DIE on the spot and cannot be started again. When this happens, the truck is *completely* dead electrically - door locks don't work, no dome lamp; it's like no battery is installed. I'm not sure what happens, but at some point (usually about 10 minutes or so) it just works again, like nothing was ever wrong.
Is the ECM a goner? What could cause this?
EDIT: More oddity - when the truck is running with no electrical issue, it shows a "check engine". After the truck resets, dies and comes back, check engine is OFF, but it runs WORSE. After a while (a few miles) it will improve and then Check Engine comes back on. Really.
Thanks,
Last edited by ZagiFlyer; September 12th, 2012 at 5:40 PM.
#4
CF Active Member
Join Date: Nov 2011
Location: Idaho
Posts: 177
Likes: 0
Received 0 Likes
on
0 Posts
also you might want to look at the battery terminal conectors i read a few post where the insides rotted out but it looked fine on the outside it could be you only have a few strands of wire that are good inside so its making it hard to get power. just a thought and a cheap replacment
#7
Start at the very beginning of the problem... clean your battery terminals, the ground connection to the fender, any other terminals that are the main power, put some Dieelectric grease on them before you put them back on. next step would be the Ignition system, clean all terminals, inspect the parts. next would be the computer. If that dont work. Might be time to start replacing parts
Trending Topics
#8
Do what Jesse said.
If it acts like there's no battery, treat it as though the battery were losing its connection. The battery connection is highly likely, easy and cheap to correct... do it first. Don't even think of starting to replace parts until you've made darn sure that your battery connection is solid. Not by looking. By opening it up and cleaning it thoroughly. Both battery cables, at both ends. Sometimes a thin layer of oxide can take a good-looking battery connection and cut it off COMPLETELY. So do the whole job on the battery cables, THEN start looking into other things. Again, cleaning connectors rather than replacing parts just yet.
Having done that, see if you can reproduce the issue by wiggling stuff, starting at one end of the system and going toward the other -- follow the wires through the fuse box and to the ignition switch, to the computer, wiggling each connection. At some point you will find a loose wire or corroded connection that intermits when you shake it.
Oh, and... the way the CEL goes out after a reset, and it runs poorly for a spell, and then runs better... that's also consistent with a battery connection. Because it's consistent with the computer losing power. When you first reset the computer (by cutting off all power) it 'forgets' its tuning info and has to start from scratch with figuring out what mixture works best. So it begins with factory tuning which isn't quite dialed for your specific engine, but is good enough to run. Runs less well for a few minutes while it's figuring that stuff out, taking readings from the O2 sensor to tune itself while you drive. Normal behavior, no big. Except that your CEL comes back on in a few minutes, which is a totally separate issue. Anyway, this strongly suggests that the problem is complete whole-truck power outage, way before your ignition switch, which means it's happening at the battery.
I wouldn't necessarily suspect the computer at this point. It's pretty normal for a computer to not work well when it's not getting power...
Finally, don't rule out the battery itself: they occasionally can fail totally rather than just not holding a charge. A failed connection between the post and the plates inside the battery can do this. Very, very hard to detect or test for... until it finally fails completely, at which point you call AAA.
Anyway, my money's on the battery connections.
Having done that, see if you can reproduce the issue by wiggling stuff, starting at one end of the system and going toward the other -- follow the wires through the fuse box and to the ignition switch, to the computer, wiggling each connection. At some point you will find a loose wire or corroded connection that intermits when you shake it.
Oh, and... the way the CEL goes out after a reset, and it runs poorly for a spell, and then runs better... that's also consistent with a battery connection. Because it's consistent with the computer losing power. When you first reset the computer (by cutting off all power) it 'forgets' its tuning info and has to start from scratch with figuring out what mixture works best. So it begins with factory tuning which isn't quite dialed for your specific engine, but is good enough to run. Runs less well for a few minutes while it's figuring that stuff out, taking readings from the O2 sensor to tune itself while you drive. Normal behavior, no big. Except that your CEL comes back on in a few minutes, which is a totally separate issue. Anyway, this strongly suggests that the problem is complete whole-truck power outage, way before your ignition switch, which means it's happening at the battery.
I wouldn't necessarily suspect the computer at this point. It's pretty normal for a computer to not work well when it's not getting power...
Finally, don't rule out the battery itself: they occasionally can fail totally rather than just not holding a charge. A failed connection between the post and the plates inside the battery can do this. Very, very hard to detect or test for... until it finally fails completely, at which point you call AAA.
Anyway, my money's on the battery connections.
Last edited by McBob; November 6th, 2012 at 9:45 AM.
#9
Fixed!
Hello to All,
This was indeed weird - I replaced the knock sensors and ALL the issues vanished. Somehow the faulty knock sensors appear to have been causing the computer to cycle or something.
At any rate, the issue is resolved -- thanks VERY much for all your help!
This was indeed weird - I replaced the knock sensors and ALL the issues vanished. Somehow the faulty knock sensors appear to have been causing the computer to cycle or something.
At any rate, the issue is resolved -- thanks VERY much for all your help!
#10
This is my first post. Having trouble (not user friendly). I have a 2006 Silverado. I added a new aftermarket CD radio. Installed a new harness interface. When ever the trucks interior get too warm or hot the radio turns off and on with the door chimes dinging away! I can turn on the air conditioning, cool the cab down and then everythings fine. In the summer when you first get in, with a hot cab it starts in right away. I figured the circuits in the interface, behind the radio, were getting hot and shutting down. I have replaced this interface about 3 different times with different brands (their not cheap) to no avail. Does anyone have a clue what I can do? P.S. When I first hook the radio up with the interface I had problems starting the truck (anti theft?) until I disconnected the interface harness and reconnected. Somebody please give me some good advice! Larry