Reduced Engine Power
Thread Starter
Drifting
Joined: Jun 2015
Posts: 1,437
Likes: 166
Reduced Engine Power
Just when the weather starts to look great and I get this message with code P2138. There's a thread about this in the tech section and I've read it. It just sucks. I rarely drove it during the winter. I was wondering if cold weather had anything to do with it since my vette is parked outside underneath a car cover. It's raining now so I'll have to wait for a sunny to look into it.
Burning Brakes
Joined: Nov 2016
Posts: 783
Likes: 224
From: Chilliwack BC Canada
Just when the weather starts to look great and I get this message with code P2138. There's a thread about this in the tech section and I've read it. It just sucks. I rarely drove it during the winter. I was wondering if cold weather had anything to do with it since my vette is parked outside underneath a car cover. It's raining now so I'll have to wait for a sunny to look into it.
The fellow who made the video was able to source the circuit board without having to replace the whole throttle motor assembly and it fixed the power loss problem.
Last edited by Icecap; Mar 30, 2017 at 03:51 PM.
Thread Starter
Drifting
Joined: Jun 2015
Posts: 1,437
Likes: 166
I recently watched a YouTube video that I'm not sure where I found the link to it from, possibly a post on this forum. The problem was tracked down to a flaw in the circuit board of the throttle motor. The contacts of the circuit board relay the throttle position to the ECM. Evidently the flaw in the sliding contacts that are similar to those used in a fuel tank level gauge was not visible to the naked eye but was very apparent under magnification.
The fellow who made the video was able to source the circuit board without having to replace the whole throttle motor assembly and it fixed the power loss problem.
The fellow who made the video was able to source the circuit board without having to replace the whole throttle motor assembly and it fixed the power loss problem.
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
You might need a new gas pedal assy. P2138 is often associated with a bad Accelerator Pedal Position Sensor.
Example to look at:
https://www.corvetteforum.com/forums...raction-2.html
Example to look at:
https://www.corvetteforum.com/forums...raction-2.html
Race Director
Joined: Dec 2002
Posts: 10,468
Likes: 1,149
From: Wayne Township WI
I'd a one-in-a-million issue which resulted in REP on my '06.
Limped it home, dealer flat bedded it in where it was for several days while they tried troubleshooting problem.
I got it back after a few days, was fine.
Turned out dealer's sr wrench was on vacation, and since young guys couldn't find a thing they waited for his return -- explaining wait.
Old timer crawled around w/ flashlight, poked & prodded & sure enough.
Somehow, someway a plug wire came loose & welded itself on header.
Could not be seen from above, had to search & trace & not assume anything.
Took old school troubleshooting skills ie 'looking', testing or car might still be there.
Be sure to physically check plugs/boots for tightness & overall integrity.
Sure would be nice if this turned out something simple, at least there's a code. G/L
Limped it home, dealer flat bedded it in where it was for several days while they tried troubleshooting problem.
I got it back after a few days, was fine.
Turned out dealer's sr wrench was on vacation, and since young guys couldn't find a thing they waited for his return -- explaining wait.
Old timer crawled around w/ flashlight, poked & prodded & sure enough.
Somehow, someway a plug wire came loose & welded itself on header.
Could not be seen from above, had to search & trace & not assume anything.
Took old school troubleshooting skills ie 'looking', testing or car might still be there.
Be sure to physically check plugs/boots for tightness & overall integrity.
Sure would be nice if this turned out something simple, at least there's a code. G/L
Last edited by Landru; Mar 30, 2017 at 04:33 PM.
Melting Slicks
Joined: Dec 2013
Posts: 2,232
Likes: 315
From: Bridgewater New Jersey
Just when the weather starts to look great and I get this message with code P2138. There's a thread about this in the tech section and I've read it. It just sucks. I rarely drove it during the winter. I was wondering if cold weather had anything to do with it since my vette is parked outside underneath a car cover. It's raining now so I'll have to wait for a sunny to look into it.
I do not believe that the part is serviceable like the video posted here.
Earlier cars would have the sensor bolted to the outside of the throttle body, which made it easy to replace.
There's a possibility that the wiring to the throttle body could be at fault, as some have been know to have broken wires inside the coated plastic insulation near the connector.
Here's some more to read if your interested in fixing this problem yourself.
https://www.yourmechanic.com/article...y-andrew-quinn
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Thread Starter
Drifting
Joined: Jun 2015
Posts: 1,437
Likes: 166
I was able to rev up to 3k rpm and nothing happened, just went back under 2k rpm and slowly speed up. I've read all the possibilities y'all posted on what may have caused the problem. It's really hard for me to believe that it happened to my 2008 with only 12k miles. I hope it's not due to mice though. I rather buy a whole new TB than deal with mice. Weather needs to brighten up asap. Thanks y'all.
Le Mans Master
Joined: Sep 2014
Posts: 7,001
Likes: 988
From: lake havasu city arizona
I was able to rev up to 3k rpm and nothing happened, just went back under 2k rpm and slowly speed up. I've read all the possibilities y'all posted on what may have caused the problem. It's really hard for me to believe that it happened to my 2008 with only 12k miles. I hope it's not due to mice though. I rather buy a whole new TB than deal with mice. Weather needs to brighten up asap. Thanks y'all.
Good luck
NSF
Melting Slicks
Joined: Dec 2013
Posts: 2,232
Likes: 315
From: Bridgewater New Jersey
I believe that this one is not serviceable.
Last edited by extrapilot; Mar 31, 2017 at 04:15 PM.
Thread Starter
Drifting
Joined: Jun 2015
Posts: 1,437
Likes: 166
Melting Slicks
Joined: Dec 2013
Posts: 2,232
Likes: 315
From: Bridgewater New Jersey
Thread Starter
Drifting
Joined: Jun 2015
Posts: 1,437
Likes: 166
Update
So I replaced the old TB with the new one from Rock Auto. Price for the TB was $337.78 and it was the lowest price I could find. It was shipped Monday and came today. IMO, it was fast. The hardest part was putting back the intake on the support mounts on the radiator. It was a bitch 
After the replacement, I took my vette for a drive. I drove about 5 miles and WOT hitting 130mph. No check engine light or "reduced engine power". I hope this fixed the problem. I plan to drive more tomorrow if it don't rain. If all goes well, I'm willing to give the used broken TB away for free to anyone that lives close to me that wants it. All I ask is that you keep the spirit of giving alive. Thank y'all 
After the replacement, I took my vette for a drive. I drove about 5 miles and WOT hitting 130mph. No check engine light or "reduced engine power". I hope this fixed the problem. I plan to drive more tomorrow if it don't rain. If all goes well, I'm willing to give the used broken TB away for free to anyone that lives close to me that wants it. All I ask is that you keep the spirit of giving alive. Thank y'all
Last edited by Zero_6; Apr 5, 2017 at 09:10 PM.
Le Mans Master
Joined: Sep 2014
Posts: 7,001
Likes: 988
From: lake havasu city arizona
I hate doing that crap, of never knowing for sure.
Good luck
NSF
Thread Starter
Drifting
Joined: Jun 2015
Posts: 1,437
Likes: 166
I don't know of any expert but there are performance shops around though. I just purchased the accelerator pedal from rockauto, that'll be my last purchase. I wonder if the Vitesse Throttle Controller has anything to do with it. I'll fiddle with that tomorrow.