Traction Control & Reduced Engine Power
 

I have a C6 Corvette with 2000 miles on it that is plagued with several problems I hope some one else can confirm. The dealership can not correct the problem and it is in the shop again for the 4th time.

While driving at normal conditions the "Service Traction Control" warning starts alarming, the "Check Engine" light illuminates and the "Engine Operating Under Reduced Power" warning comes on. The engine actual operates at reduced power and the throttle has to be depressed twice as much to make the vehicle operate. Performance is greatly reduced.

They have replaced a throttle sensing unit and the entire gas pedal assembly and the problem still exists. They are now saying that a problem exist in a wiring harness. This is getting old quick as the Vette is in the Service bay more than I drive it.

Any other C6 owners with the same problem out there. Please respond.

ONe member said that they had the ECM of an Auto? Basically the COMPUTER in the car was not for the Manual. Do you have Manual or Automatic? Might want to have the dealer check that out.

I have zero problems with traction contol/active handling - except I pulled a SickRick; but didn't suffer any damage. :willy:

JK

I feel your pain. Really. I've seen a whole bunch of this with my C6. It has been in the shop 7 times for 30 working days. They think that they have it fixed, again. I just sent a nasty letter to GM regarding this. Here is a snippet of that letter.

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I bought my 2005 Corvette on December 29, 2004, from my local Chevy Corvette dealership, (name removed). It had just come off the transport truck from Bowling Green, KY.

It was working fine for approx 6 weeks. Then the troubles began. I was casually driving home for lunch one day, going about 25 mph in my subdivision, and all of the sudden the dash lights up and the DIC is complaining about “Reduced Engine Power” and “Service Traction System”. I scheduled an appointment with my dealership's service center.

Herefore, I will appreviate “Reduced Engine Power” as “REP”, and “Service Traction System” as “STS” because they happened a lot.

2/14/2005 - First visit to the dealership service center. It was still acting up in REP/STS mode, and I left the engine running as I brought it in for service. The Corvette tech came out and took a quick look at it, and after a minute or two, he turned it off. 30 or 45 minutes later when they could bring it into the garage, it was not acting up, and they could not reproduce the problem. They cleared the codes, and gave it back to me saying, effectively, “I hope it doesn't happen again, but I'm sure it will.”

Over the weekend it went into REP/STS a few times, but because the service department was not open, I couldn't do anything about it. There were 2 times when active handling engaged, and due to its electrical glitches, it was improperly making “corrections”, and gave me more than a handful to keep from wrecking. On the morning of 2/22/2005, the passenger side door came open while I was driving into the office. There was no way anything could have hit the open-door button or pulled up on the manual release. The only thing preventing it from being a major disaster is that the glass did not index down, and it was barely hanging into the roof panel. I brought it into the dealership that morning.

2/22/2005 - Second visit to the dealership service center. It wasn't acting up at the moment, but the serious safety issue of the door coming open by itself while driving could not be ignored. They saw a huge number of codes. They didn't know what to do. I had one modification to the vette: I had a radar detector connected to a dc 12v supply. They told me to remove it, and when it acts up again, bring it in. I clearly told them that I was about to go on a roadtrip from BFE, MS to Austin, TX, and I was going to be extremely upset if it acted up on the way.

A few hundred miles into my roadtrip to/from Austin, guess what? It went into REP/STS mode again. It was barely limping all the way to Austin and back. The onStar guy wasn't much help. His ran the remote vehicle diagnostics, and his reaction was along the lines of “your car is still running?” I was going there for an important business meeting, and I didn't make a 1400 mile trip to be stuck in a service center.

2/28/2005 through 3/11/2005 - Third visit to the dealership service center. 10 full working days and 2 weekend days in the shop. It was regularly going into REP/STS mode, and I had to stress how upset I was with its pitiful behavior on my trip to/from Austin. They replaced the ECM and all kinds of wiring and connectors. And for a while, I thought they had it fixed. However, the fix turned out to be temporary.

5/27/2005 through 5/31/2005 - Fourth visit to a dealership service center. 1.5 working days, and 3 weekend/holiday days in the shop. This time it let me down while I was on a Corvette cruise-in vacation in Bowling Green, KY. This time it wasn't limping around in REP/STS mode, but was dead, and had to be towed to a dealership service center. They replaced the ECM (again). I didn't have the luxury of waiting for it to be fixed. I had to get back to work in MS.

They had it fixed for a little while, but not for long.

6/16/2005 through 6/24/2005 - Fifth visit to the dealership service center. 7 working days and 2 weekend days. REP/STS had returned. Although it wasn't doing it all the time, it had acted up 3 or 4 times in the previous 2 days. This disease only gets worse once it starts. However, the dealership could not get it to reproduce the problem. They cleared the codes, gave it back to me. They knew I'd be back soon.

7/7/2005 - Sixth visit to the dealership service center. It was acting up in REP/STS mode, and I left the engine running when I got there. The Corvette tech came out with his diagnostic tool, plugged in, and saw what it was doing. He could not pinpoint the cause, though. He cleared the codes and gave it back to me. 20 minutes after leaving the dealership, it acted up again. They were reluctant to write a service ticket because they know it was in lemon territory.

7/8/2005 through 7/22/2005 - Seventh visit to the dealership service center. 11 working days and 4 weekend days. It was acting up in REP/STS mode, and I left the engine running when I got there. They could finally reproduce the problem. I made it very clear to them that I was moving from BFE, MS to Austin, TX on 7/14/2005, and that 7/13/2005 would be my last day in the area. Extremely clear. They thought they found the problem, and they replaced the throttle position sensor. Either on 7/12/2005 or 7/13/2005, they called and told me that the new throttle position sensor did not fix it. I could either take a broken car with me to TX, or I could let them continue to fix it. I was extremely disappointed. I was extremely inconvenienced. I didn't want to limp around in a dysfunctional new 2005 Corvette on another trip to TX, so I left it with them to continue to fix it.

In theory, it is fixed again. Will it last more than 6 weeks this time? Time will tell. But its history cannot be changed. In less than 7 months and less than 6500 miles, it has been in the shop for 30 full working days, and an additional 11 holiday and weekend days. 41 days of downtime. This is a brand new 2005 Corvette spending 20% of its time in the shop.
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I think that the final "fix" they have done, they found some connector with significant corrosion around it. They either cleaned it up or replaced it, and now it is working again. I'm going back to MS this weekend to pick it up. Life in a rental car has been miserable.

Not sure if it's the same as my C5 , but when I got the exact same errors I found it was the ACM (Actuator Control Module).

Just got back after flying to BFE, MS, and driving my lemon back to Austin, TX. The final fix sheet describes the actions taken as:

"Customer states traction control light on, reduced engine power, lights on
Checked codes(P2127) cleared code and rechecked (code came back) checked app sensor 2 operation (inop at times) checked for app sensor 2 low reference, 5 volt referance, and signal at sensor 2 (none) checked for above signals at pcm (ok)
Rewired circuit 1272 from pcm to app sensor 2 at terminal at pcm, rewired circuit 1274 &1162 from pcm to app sensor 2 and terminal at pcm. Cleared codes and rechecked (code reset at times) checked signals at app sensor 2 (ok) r/r accel pedal assembly (sensor has internal fault) cleared codes (reset engine speed circuit code) replaced terminal at #48 cavity of c1 (blue connector) at pcm.
Test drove vehicle extensively. No more codes after repair"

The only parts listed are
1 of 12569599 Pedal 3.451

Well, it behaved on the 700 mile trip today, and the outside temperatures even got up to 99 degrees. High outside temperatures and running it for long periods of time tended to make it act up more frequently. Maybe they have it fixed this time? I'm still skeptical.

Traction, abs, etc lights on
 

My 05 corvette has about 6,000 miles, took the car in over three weeks ago for service lights coming on (abs, traction). the dealership replaced the abs sensor in the front, now the ecm, but it wont start now. They said they got it started for a few minutes, but sensor codes were going off everywhere. No idea when i will be getting it back.

Just had the same thing happen to me. "Service Traction Control and Reduced Engine Power" I think my problem was in the console traction control switch. It just didn't feel right. I squirted some contact cleaner WITH LUBRICANT into the switch and the problem went away. WHEW!! Reduced engine power is no fun at all!

Gray

Just saw your post from an old thread....I just had the same problem with my '08 C6....I've got 54,000 miles on mine and was out at lunch on the freeway...doing about 75 mph when BAM the reduced engine power hit and the service engine light and traction control light came on....Was wondering if you ever had a problem after trying the contact cleaner...

will see if I have the same luck you did...thanks for the post!