Alright so about last week i got a CEL and along with that i got ENG PWR REDUCED. I Plugged the scanner in, deleated it, and it was gone. 2 days later it happend again. So i took it to the dealer ship. I have a catless downpipe on my car and rear 02 sensor is deleated so they claim there not going to fix it because, i have the pcm tuned. And thats what is causing the problem. I talked to the tech and asked him how he's sure it was teh pcm and he wouldnt answer me nore look me in the eye. I got pissed and left. I was able to drive another 2 days without problems and then all the sudden i cant drive at all without getting the code to throw. And today no problems, even did a little spirited driving, and nothing. Left 30 min later and again i got the code. I dont know what the deal is. Any ideas? The code is P2135 which read Throttle/ Pedel Position Sensor

 

Bump!!

 

Well they can't turn you away because of your mods to your exhaust, if you have a PCM tune they might be able to. If your PCM is stock then the issue is unrelated to the mods and they can't say **** about it.

 

The only thing i have done is the rear o2 delete. I can have that taken care of to where that will throw the code and then they shouldnt be able to say anything.

 

This should help


Service Information
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2006 Chevrolet Cobalt | Cobalt, Pursuit (VIN A) Service Manual | Document ID: 1889565
#07-06-04-003: LSJ, L61, LK5, L52, LL8 Engine - Reduced Engine Power, MIL/SES Light, DTC P1516, P2135, P2138 (Replace PCM) - (Jan 19, 2007)

Subject: LSJ, L61, LK5, L52, LL8 Engine -- Reduced Engine Power, MIL/SES Light, DTC P1516, P2135, P2138 (Replace PCM)

Models: 2005-2006 Chevrolet Cobalt, Cobalt SS, Malibu
2006 Chevrolet Colorado, TrailBlazer
2006 GMC Canyon, Envoy
2006 HUMMER H3
2005-2006 Saturn ION, ION Red Line
2006 Saab 9-7X
with ECOTEC™ 2.0L, 2.2L I-4 Cylinder Engine (VINs P, F-- RPOs LSJ, L61) or
VORTEC™ 2.8L I-4, 3.5L I-5, 4.2L I-6 Cylinder Engine (VINs 8, 6, S -- RPOs LK5, L52, LL8)

Attention: The following bulletin information is only to be used if the customer has returned for REPEAT repairs for DTCs P1516, P2135 and/or P2138.
Condition

Some customers may comment on engine operation in the Reduce Engine Power mode with the MIL/SES light illuminated. This condition may be repeated and upon investigation, the technician may find the following DTCs set as current or in history:
• DTC P1516 Throttle Actuator Control (TAC) Module Throttle Actuator Position Performance
• DTC P2135 Throttle Position (TP) Sensor 1-2 Correlation
• DTC P2138 Accelerator Pedal Position (APP) Sensor 1-2 Correlation
Cause

This condition of a repeat DTC P1516, P2135 and/or P2138 may be caused by an internal concern with the PCM.
Correction

Object Number: 1885980 Size: SH
Click here for detailed picture of above image.

Important: DO NOT replace the APP sensor. Inspect the PCM build date first.

Before following the diagnostic information in SI on DTCs P1516, P2135 and/or P2138, an inspection of the PCM serial number year and Julian (PCM build) date will be necessary to determine if the PCM will need to be replaced to correct the repeat DTC P1516. Refer to Engine Control Module Replacement in SI in order to remove the PCM. Refer to the above graphic illustration (1) for the location of the PCM serial number.

The serial number is read left to right. The last digit of the year is the 9th character and the Julian date is comprised of the 10th, 11th and 12th characters and is used to determine the PCM build date. Refer to the example below to read a build date from the PCM serial number:

* 8 6 Y N AU K 1 5 3 2 5 0 R P N *

If the PCM year and Julian dates are between 5182 and 5304 , replace the PCM. Refer to the Part Catalog to order the correct PCM for your vehicle application, if necessary.

Vehicles with PCM built outside the dates should refer to SI diagnostics for DTCs P1516, P2135 and/or P2138.
Warranty Information

For vehicles repaired under warranty, use:

Labor Operation


Description


Labor Time

J6360


Powertrain Control Module Replacement


Use Published Labor Operation Time
Warranty Information (Saab U.S. Models)

For vehicles repaired under warranty, use:

Labor Operation


Description


Failed Object


Fault/Reason Code


Location Code


Warranty Type


Repair/Action Code


Labor Time

2481001


Powertrain Control Module Replacement


24810


67


0


01


01


Use Published Labor Operation Time

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
Š 2009 General Motors Corporation. All rights reserved.

 

Have you recently unplugged your tps sensor? i.e. the electrical plug going into the throttle body

I would start there, I got that code and problem for a while, and it ended up being a loose wire from where I had tapped the nitrous and pulled that wire a lil too hard, I pushed it back down in to the connector as far as I could and voila no more eng pwr reduced

l8r,
PD

 

Nope i have checked all connections to throttle body and pedel. Everything checks out.

 

Ok, well then I would have the PCM checked, good luck, I hope it gets to running right again soon.

l8r,
PD

 

It was the Throttle body...

 

I just want to insert my $.02. I too have been going bonkers for the last month with this engine power reduced problem. I have been having p0420, p1681, and p2135. Now p0420 im aware of because my pcm was tuned to have the o2 sensor turned off, don't really understand why its coming up. the other two codes I have I have been lead to believe that the pcm is the problem. Now that I am reading this bulletin, I'm now having second thoughts. Maybe I need to check my tps wires too, because I put nitrous on my car and possibly also pulled a tps wire too hard.

 

Just got out of the dealership with my problematic 06 SS/SC. I was getting several codes related to the throttle body position sensor, rear 02 sensor, clutch pedal position switch, engine misfiring, etc etc.

The PCM was suspected of being faulty right from the start. The julian date on the PCM confirmed it was the same type as the factory one that GM put in the car. (Every mechanic I talked to told me that original PCM was the problem with reduced engine power mode).

Make sure if you do get a new PCM that it is tuned correctly and that the dealership test drives the car before they return it to you. I have had a many unfortunate trips to the dealer because my car went into limp mode and wouldn't start.

If that doesn't work, check to make sure your connections are properly grounded, as they found several of my wires were kinda loose running to my PCM.

Hope this helps.

 

i am having this problem. my pcm is 5307....just missed the date. so i think it's my throttle body due to meth injection. i'm having an evap code come up too. must be my gas cap. i have to take care of these codes, re install my airbag, pass inspection, re-register the car in 15 days or my insurance gets dropped and my car gets reposessed. LOL. it's ok, i'll figure it out.

 

i am having the same similar issue right now car feels like i am on the pedal even in nutral and consistantly goes into "limp mode"

 

Most of the time when someone with a balt has a TPS related dtc it is the throttle body. I had the same problem as the OP and replaced the pcm but it turned out to be the throttle body. Mine gradually got to where I couldnt go a block without it going into limp mode.

 

Ya thats the boat im in waiting to hear back from gmparts direct....any issues with limp mode after replacing the throttle bdy?

 

Are the PCM's being faulty something that is covered as a recall or extended service?

 

Unless you still have warranty i dont think so. Your pcm is faulty?

 

Go to another dealership, any dealership that brings up your pcm is shitty.

 

PCM is covered under 8yr/80k mile federal emissions warranty.

 

Maybe. I started getting a TPS correlation code and found this thread. I have already replaced my gas pedal and did a write all on my PCM. Cleared it up for a week and then this morning it did it again. I was going to replace the TB but then came across this.

I dont go to dealerships. I do all of my own repairs and diagnostics.

 

A new PCM didn't fix mine. New TB didn't fix it either.

 

It is on my LSJ.
TB and connector first.
Fire if that doesnt fix it.

 

You're gonna have to burn it. If a new alternator doesn't magically fix mine, mine might have the same fate. Fortunately gas is cheap right now.

 

If I shut the code off will the car still go into limp mode?

Have your battery tested. Bad cells cause these cars to do funky things.

 

If you clear the code it should start normally till the offending code is thrown again. I don't even have to clear the code for it to start normally the next time. But different ECU.

The battery was new with the engine (douchebag dealership drained my battery while it sat there). My junkyard alternator appears to not be charging it properly, despite the positive bench test. But I will have the new one tested anyways. Could still be bad.