stabilitrac, power reduction and check engine light
November 22nd, 2013, 12:32 PM
#11
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I am really surprised and disappointed that GM doesn't have an exact bulletin/fix identifying this potentially dangerous situation by now given that it has been going on since at least 2003. Any/all of the repairs directed to the REP message/actions have been hit and miss on their results. This is NOT developing a very good reputation for the product line.
November 27th, 2013, 7:28 AM
#12
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So as I said before I have the same issue. Called 3 different dealers to be told my particular vehicle isn't covered under the TSB due to my vin# (I believe it's a generic response). Anyway I priced the harness that goes into the throttle body from the dealer it was $69. My harness wires seemed crimped so I ordered it. My truck would go into reduced power mode 5-8 times a day getting frustrated I decided I would park the truck rent a car til I figured it out. On the way home I stopped in auto-zone to have them check the codes since all the lights on the dash was on. I got several codes pedal sensor, oxygen sensor, throttle body sensor and 3 more codes I can't remember. Even the guy said all these issues can't be true something is sending errors codes falsely to the computer and his exact words were "maybe a old or dirty sensor somewhere". After a few question I bought some throttle body spray cleaner. When I got home I parked it in the driveway got some old towels and a toothbrush. I cleaned the hell out of the throttle body used the toothbrush to clean and gently scrub the inside of the throttle body and the sprayed inside some more. It seemed as if a gallon of black gunk came out of that thing. When the can was almost finished and I was satisfied with the cleansing I put the intake back on and started her up. ALL LIGHTS TRACTION, STABILITRACK AND ENGINE LIGHT WENT OFF!!!!! I thought it was a fluke so I hit the highway and no lights came on. Ive been driving the Burban now almost 2 weeks with no issues full power is back and not sluggish most importantly no warning lights. My opinion is that so much carbon builds up that it kicks off the codes to that throttle body sensor. I say give this a shot it only cost me $6 for the spray. I will clean mine every month. I will also change my plugs and wires and the harness I ordered but so far so good. Sorry for the long post oh and my truck is a 07 Burban ltz. Hope this helps
December 2nd, 2013, 10:56 AM
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So as I said before I have the same issue. Called 3 different dealers to be told my particular vehicle isn't covered under the TSB due to my vin# (I believe it's a generic response). Anyway I priced the harness that goes into the throttle body from the dealer it was $69. My harness wires seemed crimped so I ordered it. My truck would go into reduced power mode 5-8 times a day getting frustrated I decided I would park the truck rent a car til I figured it out. On the way home I stopped in auto-zone to have them check the codes since all the lights on the dash was on. I got several codes pedal sensor, oxygen sensor, throttle body sensor and 3 more codes I can't remember. Even the guy said all these issues can't be true something is sending errors codes falsely to the computer and his exact words were "maybe a old or dirty sensor somewhere". After a few question I bought some throttle body spray cleaner. When I got home I parked it in the driveway got some old towels and a toothbrush. I cleaned the hell out of the throttle body used the toothbrush to clean and gently scrub the inside of the throttle body and the sprayed inside some more. It seemed as if a gallon of black gunk came out of that thing. When the can was almost finished and I was satisfied with the cleansing I put the intake back on and started her up. ALL LIGHTS TRACTION, STABILITRACK AND ENGINE LIGHT WENT OFF!!!!! I thought it was a fluke so I hit the highway and no lights came on. Ive been driving the Burban now almost 2 weeks with no issues full power is back and not sluggish most importantly no warning lights. My opinion is that so much carbon builds up that it kicks off the codes to that throttle body sensor. I say give this a shot it only cost me $6 for the spray. I will clean mine every month. I will also change my plugs and wires and the harness I ordered but so far so good. Sorry for the long post oh and my truck is a 07 Burban ltz. Hope this helps
I'm not a professional mechanic. But after a few Angry Orchards, I think I am.
January 14th, 2014, 1:11 PM
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Had all that happen to my 2007 LTZ 4wd plus a broken shift cable. I think that I picked up a stick going through a puddle, or at least that's what it sounded like.
Either way replaced the cable and the dealer said they had to rebuild a portion of the wiring harness and clean the throttle body. $1,000 in all. I have 134k and the engine runs great, but the maintenance sure gets pricey on the gadgets when you are out of warranty.
Now I am trying to decide between the 2015 denali or suburban.
Either way replaced the cable and the dealer said they had to rebuild a portion of the wiring harness and clean the throttle body. $1,000 in all. I have 134k and the engine runs great, but the maintenance sure gets pricey on the gadgets when you are out of warranty.
Now I am trying to decide between the 2015 denali or suburban.
January 16th, 2014, 5:15 PM
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We have had a similar problem. Started last Thursday and $625 later and week without Tahoe we were told rattling in engine is causing problem. Now we have to choose between getting into engine, replacing it or buying new vehicle. Get it checked out now. Best case is $2000 to get into engine and it's only the lifter. We had plugs, wires, and 1 cylinder something replaced and they cleaned throttle body. Had 4-wheel drive control thing replaced 3-4 weeks ago @ $500. We are $1100 in and need another 2 weeks in the shop and at minimum $2000 to get it running. Very frustrated.
2007 Tahoe LT w/100k mileage.
2007 Tahoe LT w/100k mileage.
Last edited by gshirdon; January 16th, 2014 at 5:22 PM.
February 13th, 2014, 1:27 PM
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Update on this issue. I have the 07 burb ltz with 135k. First time the issue occurred they cleaned the throttle body and fixed a wiring harness where the O2 sensor wires were pulled out. ($850)
That worked for a week....
Next time in, they had the truck all day, and couldn't find the cause, but finally changed a vacuum hose to fix the issue. (no charge, thankfully)
That worked for two weeks....
This time, the truck went into safe mode and said reduced power. Supposedly a gas pedal sensor was registering with high resistance. One of the techs had just been to GMs tech school and learned that a wiring harness bypassing the sensor was the best way to go. Supposedly cheaper than the fix. ($222)
This has been working for 4 days without a problem yet....
Keeping my fingers crossed and hoping I can make it to the next model release. But honestly all this crap has me wondering.
That worked for a week....
Next time in, they had the truck all day, and couldn't find the cause, but finally changed a vacuum hose to fix the issue. (no charge, thankfully)
That worked for two weeks....
This time, the truck went into safe mode and said reduced power. Supposedly a gas pedal sensor was registering with high resistance. One of the techs had just been to GMs tech school and learned that a wiring harness bypassing the sensor was the best way to go. Supposedly cheaper than the fix. ($222)
This has been working for 4 days without a problem yet....
Keeping my fingers crossed and hoping I can make it to the next model release. But honestly all this crap has me wondering.
February 13th, 2014, 1:49 PM
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No info on the harness he was talking about. Description is as follows:
135316 High resistance in wiring for app sensor 2.00, scan for codes found P2138 stored current unable to accel reduced power light on, CL all realated circuits to app sensor assembly, determined possible high resistance on low reference circuit, rewire entire ciruit eliminating both connectors c109 and c205, road test ok
Have to leave that to you to decipher. I don't think they want to see me anytime soon.
135316 High resistance in wiring for app sensor 2.00, scan for codes found P2138 stored current unable to accel reduced power light on, CL all realated circuits to app sensor assembly, determined possible high resistance on low reference circuit, rewire entire ciruit eliminating both connectors c109 and c205, road test ok
Have to leave that to you to decipher. I don't think they want to see me anytime soon.
February 13th, 2014, 2:03 PM
#20
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He was following this procedure....
Service Information 2007 Chevrolet Tahoe - 2WD | Avalanche, Escalade, Suburban, Tahoe, Yukon (VIN C/K) Service Manual | Document ID: 2039190
--------------------------------------------------------------------------------
#PIP3783B: Reduced Power Message And Accelerator Pedal Position Code - keywords 5.3 6.0 6.2 6.6 accel acceleration APP DIC DTC engine LC9 LMG LY5 LY6 L92 mode no P2120 P2122 P2123 P2125 P2127 P2128 P2138 RPM - (Nov 20, 2007)
Subject: Reduced Power Message and Accelerator Pedal Position Code
Models: 2007-2008 Cadillac Escalade
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007-2008 GMC Sierra, Yukon, Yukon Denali
--------------------------------------------------------------------------------
This PI was superseded to update models and engines. Please discard PIP3783A.
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The customer concern may be a SES light on with a reduced power message.
Recommendation/Instructions:
Complete the current SI diagnostics for any symptoms or DTCs found. If the vehicle was brought in for a reduced power message and DTCs P2120, P2122, P2123, P2125, P2127, P2128, or P2138 were found, inspect connectors C109 and C205. Connector C109 is located on the left side of the engine compartment below the underhood fuse block. Connector C205 is located under the Upper Instrument Trim Panel. To access connector C205 use the SI procedures for Instrument Panel Upper Trim Panel with Windshield Defroster Nozzle Grille Replacement.
Inspect all terminal and pin fits at connectors C109 and C205. Make sure the connectors are properly seated and locked. Make necessary wiring repairs following SI procedures.
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
Service Information 2007 Chevrolet Tahoe - 2WD | Avalanche, Escalade, Suburban, Tahoe, Yukon (VIN C/K) Service Manual | Document ID: 2039190
--------------------------------------------------------------------------------
#PIP3783B: Reduced Power Message And Accelerator Pedal Position Code - keywords 5.3 6.0 6.2 6.6 accel acceleration APP DIC DTC engine LC9 LMG LY5 LY6 L92 mode no P2120 P2122 P2123 P2125 P2127 P2128 P2138 RPM - (Nov 20, 2007)
Subject: Reduced Power Message and Accelerator Pedal Position Code
Models: 2007-2008 Cadillac Escalade
2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007-2008 GMC Sierra, Yukon, Yukon Denali
--------------------------------------------------------------------------------
This PI was superseded to update models and engines. Please discard PIP3783A.
--------------------------------------------------------------------------------
The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:
The customer concern may be a SES light on with a reduced power message.
Recommendation/Instructions:
Complete the current SI diagnostics for any symptoms or DTCs found. If the vehicle was brought in for a reduced power message and DTCs P2120, P2122, P2123, P2125, P2127, P2128, or P2138 were found, inspect connectors C109 and C205. Connector C109 is located on the left side of the engine compartment below the underhood fuse block. Connector C205 is located under the Upper Instrument Trim Panel. To access connector C205 use the SI procedures for Instrument Panel Upper Trim Panel with Windshield Defroster Nozzle Grille Replacement.
Inspect all terminal and pin fits at connectors C109 and C205. Make sure the connectors are properly seated and locked. Make necessary wiring repairs following SI procedures.
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
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