Reduced Engine Power Issue
Thread Starter
Teching In
Joined: Mar 2017
Posts: 27
Likes: 1
From: Macomb Michigan
Reduced Engine Power Issue Hi LS1Tech,
I need help troubleshooting a issue on my 2010 Camaro SS. Its the M6 with the LS3, cam, bolt ons, and dyno tune. My issue that started 3 weeks ago is my car is going into "reduced enginer power" and throwing the P0641 code. No other codes. I can reset the car by unplugging the battery and it will drive fine with no codes as long as I drive easy. Once I try and get on it it goes into REP mode and throws the code. I have visually checked the wires to the sensors in the 5v reference circuit. Also tested voltage and with all sensors plugged in I get 5v. I have tried a new MAF and Clutch pedal sensor so far. I drove it to a electrical shop nearby and on the drive there I was getting 0 oil pressure, A/C refrigerant too hot, stabilitrak, and REP all coming on and going off randomly. Car ran perfect before, I had just changed the clutch master cylinder and this all started on the same day i finished that project. The shop I took it to told me ECM which I am sort of doubtful on. Where do I start, what should I check next or look for? I'm lost at this point and I can't go to a dealer since my car is modded and out of warranty. Any help is appreciated, please and thanks!
PS: I have an sct handheld that can datalog a few sensors. When I look at it my absolute throttle positions is at 22.xx% and goes up to 87.xx% when floored. The relative throttle position constantly stays at 50.19%? Seems odd to me.
Please any help is useful at this point, I'm losing my mind with this issue.
I need help troubleshooting a issue on my 2010 Camaro SS. Its the M6 with the LS3, cam, bolt ons, and dyno tune. My issue that started 3 weeks ago is my car is going into "reduced enginer power" and throwing the P0641 code. No other codes. I can reset the car by unplugging the battery and it will drive fine with no codes as long as I drive easy. Once I try and get on it it goes into REP mode and throws the code. I have visually checked the wires to the sensors in the 5v reference circuit. Also tested voltage and with all sensors plugged in I get 5v. I have tried a new MAF and Clutch pedal sensor so far. I drove it to a electrical shop nearby and on the drive there I was getting 0 oil pressure, A/C refrigerant too hot, stabilitrak, and REP all coming on and going off randomly. Car ran perfect before, I had just changed the clutch master cylinder and this all started on the same day i finished that project. The shop I took it to told me ECM which I am sort of doubtful on. Where do I start, what should I check next or look for? I'm lost at this point and I can't go to a dealer since my car is modded and out of warranty. Any help is appreciated, please and thanks!
PS: I have an sct handheld that can datalog a few sensors. When I look at it my absolute throttle positions is at 22.xx% and goes up to 87.xx% when floored. The relative throttle position constantly stays at 50.19%? Seems odd to me.
Please any help is useful at this point, I'm losing my mind with this issue.
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
You might want to check EVERY ground on the car. After 8 years some connections start to get a little fuzzy, and then trouble starts. Wiggle every ground wire, and look for corrosion. Anything without a solid ground will malfunction.
https://www.obd-codes.com/p0641
lots of good info here. This code alone seems to suggest PCM coding error.
lots of good info here. This code alone seems to suggest PCM coding error.
Thread Starter
Teching In
Joined: Mar 2017
Posts: 27
Likes: 1
From: Macomb Michigan
Ground I am aware of are 1 on the back of each head and 1 bigger ground on the front of the passenger side head. any other groudns cars usually have?
Thread Starter
Teching In
Joined: Mar 2017
Posts: 27
Likes: 1
From: Macomb Michigan
https://www.obd-codes.com/p0641
lots of good info here. This code alone seems to suggest PCM coding error.
lots of good info here. This code alone seems to suggest PCM coding error.
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On The Tree
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From: Braking Point, Turn In, Apex, Exit - Repeat
I had a 09 Z06 with a P0641 and what I ended up doing to find the issue was to unplug the connectors at the individual sensors and at the ECM - then I used my multi-meter to check for continuity to ground. So one end of the multi-meter was on a ground and the other probed the wires at the ECM connectors one by one. I found a wire to the A/C pressure sensor had rubbed through and was grounding out. I think I was lucky in that it was bad enough to show up with that test, but it's worth a shot.
If it happened after the clutch master install I would be looking all of the wiring for that clutch sensor over like a hawk.
If it happened after the clutch master install I would be looking all of the wiring for that clutch sensor over like a hawk.
Thread Starter
Teching In
Joined: Mar 2017
Posts: 27
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From: Macomb Michigan
TECH Fanatic
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This is an old post - might not be an issue any longer. Post #1 and 2 about PCM related to clutch. Makes sense if the sensors are monitoring clutch pedal location.
Looks as if you have to have a clutch pedal relearn?
https://www.camaro5.com/forums/showthread.php?t=153226
Looks as if you have to have a clutch pedal relearn?
https://www.camaro5.com/forums/showthread.php?t=153226
Last edited by dlandsvZ28; Nov 20, 2018 at 02:01 PM.
Thread Starter
Teching In
Joined: Mar 2017
Posts: 27
Likes: 1
From: Macomb Michigan
This is an old post - might not be an issue any longer. Post #1 and 2 about PCM related to clutch. Makes sense if the sensors are monitoring clutch pedal location.
Looks as if you have to have a clutch pedal relearn?
https://www.camaro5.com/forums/showthread.php?t=153226
Looks as if you have to have a clutch pedal relearn?
https://www.camaro5.com/forums/showthread.php?t=153226
Thread Starter
Teching In
Joined: Mar 2017
Posts: 27
Likes: 1
From: Macomb Michigan
Can anyone please send me the 5v reference circuit for a 2010 Camaro SS M6? Please I want to make sure I was given the correct one a few months ago when I started having this issue.