Need Code Help!!! Reduced Engine Power!!!
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,952
Likes: 1
From: Waveland MS
Need Code Help!!! Reduced Engine Power!!!
Okay, so my 2002 Z06 is having a Reduced Engine Power/ Service Traction Control System problem... It is throwing these codes which I would appreciate very much so if some translated.
10-PCM P1120 H C
P1220 H C
P1516 H C
28-TCS C1278 H
So here is the situation... If I go WOT with Traction Control off it will throw the REDUCED ENGINE POWER and Service traction Control immediately after I geto out of it, but if I leave Traction Control on it has not done it yet. I have not gone through multiple gears in either senario... only like a 3rd or 2nd gear pull. My car is a 402 Iron Block with a stage 4 tranny and a stock diff
because I just blew up the stage 4 dte
DTE SUCKS btw... but again I really need help with this problem. After it throws the codes I can turn the car off turn the key on Reset all of the codes and it will act completely fine until I go WOT again. Thanks for any help 
10-PCM P1120 H C
P1220 H C
P1516 H C
28-TCS C1278 H
So here is the situation... If I go WOT with Traction Control off it will throw the REDUCED ENGINE POWER and Service traction Control immediately after I geto out of it, but if I leave Traction Control on it has not done it yet. I have not gone through multiple gears in either senario... only like a 3rd or 2nd gear pull. My car is a 402 Iron Block with a stage 4 tranny and a stock diff
because I just blew up the stage 4 dte DTE SUCKS btw... but again I really need help with this problem. After it throws the codes I can turn the car off turn the key on Reset all of the codes and it will act completely fine until I go WOT again. Thanks for any help
Safety Car
Joined: Jan 2001
Posts: 4,387
Likes: 691
From: Boise ID
Off hand I would say you have a throttle position sensor problem.
The below link will help translate the codes:
http://www.gearchatter.com/viewforum43.php
The below link will help translate the codes:
http://www.gearchatter.com/viewforum43.php
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,952
Likes: 1
From: Waveland MS
Thanks for the Reply Sam I wrote all of them down. It says I have
p1120 TP Sensor 1 Circuit
p1220 TP Sensor 2 Circuit
p1516 Command vs Actual Throttle Position Performance(TAC Module)
and
c1278 TCS Temporarilly inhibited by PCM
I am leaning towards either TPS or TAC Module... I am hoping someone else has seen this problem and can tell me for sure before I go replacing.
p1120 TP Sensor 1 Circuit
p1220 TP Sensor 2 Circuit
p1516 Command vs Actual Throttle Position Performance(TAC Module)
and
c1278 TCS Temporarilly inhibited by PCM
I am leaning towards either TPS or TAC Module... I am hoping someone else has seen this problem and can tell me for sure before I go replacing.
Racer
Joined: May 2009
Posts: 263
Likes: 1
From: Andover KS
I had the exact same codes on my 2000 and it was the TPS. I'm money poor right now so I removed it and dissassembled it by prying out the pressed in clip on back and using tweezers pulled out the printed circuit ribbon and cleaned everything carefully. It now works fine again. A new one is around $125 but takes someone in China a week to make and ship to the dealer. If you're lucky and you don't have the flat pin type, but the small round plug type, the parts stores have it for $30.
Original Founding Member!
Joined: Jul 1999
Posts: 9,037
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From: Granby, MA
Cruise-In 1, 3, 9. 10 & 11 Veteran
I agree check all around the TPS....but before that, take the duct off the throttlebody and look inside to the TB and manifold and make sure nothing is obstructing the TB blade. My bro's 2001 threw these codes and the tuner was shocked when they opened it up to find a piece of his plastic/rubber ducting had come off and wedged itself into the TB plate leaving it partially opened and thus forcing the system to go into "reduced power mode" for the fact that the TB would not close all the way! (man they caught a break there, if the piece had come off it would of been inhaled by the engine and who knows what would of happened there...it was a pretty good size piece from what I was told.)
Check it out and get back to us.
Check it out and get back to us.
Last edited by XtremeVette; Jun 29, 2009 at 11:55 AM.
Racer
Joined: May 2009
Posts: 263
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From: Andover KS
Good call XtremeVette. Also doesn't hurt to lube the blade bearings with WD40 (through the throttle body bore in front) . If they start sticking you also get a code for pedal vs throttle miscompare or something like that. I had that too once.
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,952
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From: Waveland MS
I am about to go check and see if something is not shoved into the TB If not it will be in a few hours until I can change the TPS. The reason I am still leaning towards the TPS is the fact that it will only go into limp mode if I have TC off.
If not it will be in a few hours until I can change the TPS. The reason I am still leaning towards the TPS is the fact that it will only go into limp mode if I have TC off.
Thread Starter
Drifting
Joined: Feb 2008
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From: Waveland MS
Okay just checked the TB and it is Debri Free! I also noticed that under my hood is FULL of sand from driving down the beach yesterday. It then rained and I also have wet road grime under there very bad, so I am thinking that maybe the sand is messing with my grounds or TPS. So I am going to maticulously clean the grounds and under the hood and if that does not do it time for the TPS to come out. Luckily My Dad has a wrecked Z06 at his shop I can swap TPS's with and just buy him a new one if it works.
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Racer
Joined: May 2009
Posts: 263
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From: Andover KS
My TPS had a very slight amout of corrosion between it and the throttle body, and inside it had a little moisture when I took it apart. I have an open element air filter that I'm guessing takes in moisture. It has a seal to keep out water externally, but nothing to keep moisture from inside the throttle body from getting to it. You are going to need the torx screwdriver with the hole in the end for the pain in the rear bolts they use on the Throttle body.
Racer
Joined: May 2009
Posts: 263
Likes: 1
From: Andover KS
Before you pull it check out the plug on the TPS and the wires to make sure they are clean and dry. Blow out inside the plug area on the TPS if you have an air blower. That helped me 1 time with the TPS.
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,952
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From: Waveland MS
Ok, thanks everyone! I am going ot my shop as soon as I get motivated enough and he has an air blower, the torx screwdriver, and anything else I could possibly need. I am supposed to be working there today but I have 1) a REALLY BAD SUNBURN 2) a possible ear infection 3) a lot of stuff to take care of today. 
So it looks like I will be working there on my own stuff today.
So it looks like I will be working there on my own stuff today.
Racer
Joined: Aug 2003
Posts: 327
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From: Metamora IL
so to be clear, pull both body grounds and rough the terminals up, maybe some terminal cleaner. There was a post under the battery and one on the drivers front wheel well. Cant hurt to make sure that stuff is squeaky clean!
Thread Starter
Drifting
Joined: Feb 2008
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From: Waveland MS
Pro
Joined: Feb 2009
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From: North Port Florida
Was the beach on the ocean? You just cannot believe how corrosive salt water is unless you've had a boat and trailer and used it in salt water. It's like an acid bath. Please,oh please, stay away from the beach with your Corvette!
Thread Starter
Drifting
Joined: Feb 2008
Posts: 1,952
Likes: 1
From: Waveland MS