Accelerator Pedal Position, Reduced Engine Power - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

Welcome Enthusiast! If you already own a Chevy TrailBlazer or GMC Envoy or perhaps thinking of purchasing such a vehicle, then you have come to the best TrailBlazer and Envoy site on the net! Rainier, Bravada, Ascender, and 9-7x owners welcome too!

You are currently viewing our site as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to search and post topics, communicate privately with other members, respond to polls, upload content, and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.
Join Today!
Go Back   Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum > 2002 - 2009 TrailBlazer/Envoy Tech > 02-09 General Tech Q&A > General

General If it doesn't fit in any other forum is the premier GMC Envoy Forum on the internet. Registered Users do not see the above ads.
Thread Tools
Old 11-20-2010, 11:17 PM
KennyTN KennyTN is offline
Junior Member
2003 Chevy TrailBlazer LT
Sandstone Metallic 4.2L I6 2WD
Join Date: Nov 2010
Location: Nashville, TN
Posts: 3
Accelerator Pedal Position, Reduced Engine Power

I recently purchased a 2003 Trailblazer 6 cyl 4.2 with 45000 miles on it. With in the first week, the reduced engine power came on and check engine light. I took it to Autozone, and the OBD displayed two codes for Accelerator Pedal Position Sensor. They didn't have one in stock so I ordered one for, a Dorman RB699100. Once I replaced it, everything seemed to be fine, then I took a trip to Texas (800 miles each way) and on first leg of the trip the Reduced Engine power and check engine light came on after 8 hours of driving and for the next 5 hours came on a total of 24 times. I had to pull of the road each time and turn off and start engine 3 times to reset the CEL and Reducer Engine Power. After I returned from Texas, contacted the seller and they arranged a return authorization but wouldn't sell me another. I place the original part back in and since then it has gone to Reduced Engine Power 5 times in 4 weeks. I take it in to Autozone and the codes are the same... Accelerator Pedal Position Sensor (either not enough voltage or failure). I;m about to make a trip to San Diego, a 30 hour drive both ways.. I'm a little nervous about this truck shutting down in the middle of the nowhere. Any suggestions???
Reply With Quote Quick reply to this message
Sponsored Links
Old 11-20-2010, 11:59 PM
the roadie's Avatar
the roadie the roadie is offline
No longer with us
2004 GMC Envoy SLT "Roadiemobile"
Extreme Offroad Pewter 4.2L I6 4X4
Join Date: Apr 2005
Posts: 26,181
The exact codes (not the Autozone interpretation, which can be wrong) would be very useful. The reference 5V voltage for the pedal sensors is shared by the throttle butterfly valve sensors and the fan clutch RPM speed sensor.

Or it could be damaged wiring between the PCM and those three sets of sensors.

Didn't we have an owner in here in the last month or two saying he couldn't find this sort of intermittent problem and he was just going to trade it in and stick the next owner with this problem?

Seriously, we hear this sort of thing monthly - owners without the chops to troubleshoot properly and they shotgun the problem poorly and end up losing their shirt on a trade-in if they're honest, or losing karma if they sell the vehicle and aren't honest.

Did you buy it from a place that gave you a warranty, or from the previous owner in a private sale?
Reply With Quote Quick reply to this message
Old 11-21-2010, 12:28 AM
KennyTN KennyTN is offline
Junior Member
2003 Chevy TrailBlazer LT
Sandstone Metallic 4.2L I6 2WD
Join Date: Nov 2010
Location: Nashville, TN
Posts: 3
from private sale

Thank you for your reply. I purchased the 2003 Trailblazer from a widow of a GMC company man here in Spring Hill. When he passed, his widow had the truck gone over and detailed by the local GMC dealership. It's a very clean auto just this weird problem. I'm hesitant to take it to the dealership as they usually charge an exorbitant price for their work. Can you recommend any honest mechanics for this vehicle in the Nashville/Franklin TN area? The codes I based my decision on was from the OBDII unit they sell in the store. I have since misplaced the sheet with the code on it but I believe it was P1271. Your recommendations? From reading the posts here, it sounds like this is a frequent problem with these vehicles. I previously had a 2003 Envoy and never had a problem like this. Thank you for your insight.
Reply With Quote Quick reply to this message
Old 10-19-2012, 08:14 PM
Kyle931 Kyle931 is offline
Junior Member
2002 Chevy TrailBlazer LS
Magnetic Red Metallic 4.2L I6 2WD
Join Date: Sep 2012
Location: Fort Irwin, CA
Posts: 1
Dorman OE Pedal Position Sensor Problems p1271

I bought an 02 trailblazer 3 months ago and soon got the Service Engine Soon light and Reduced Engine Power light. I invested in a $60 code reader from Auto Zone (the best investment that I have ever made). I pulled up the code on the code reader and it read p1271 and p1271 p/d which means Excessive voltage difference between Accelerator Pedal Position Sensor 1 and 2. After looking at my Hayne's manual and forums I decided to order a new APP Sensor which is built into the gas pedal. I went cheap and bought the Dorman OE replacement APP Sensor fir $70. For those of you who don't know, OE is a cheaper (in both ways) version of the original part. I put the new APP sensor in and it ran without lights or codes for a few weeks before getting the SES and REP lights. After tons of forums, checking wires, a throttle body, and later I found on a forum that the Dorman OE replacement is junk and there is a high chance of it going bad after a few weeks. I am about to buy an OEM replacement and I will keep you posted on how it turns out.

I have found a lot of people on forums with no decent answers, so hopefully this helps the people in the same boat as myself.
Reply With Quote Quick reply to this message
Old 10-19-2012, 11:32 PM
wcosh's Avatar
wcosh wcosh is offline
2003 Chevy TrailBlazer LT EXT
Dark Green Metallic 4.2L I6 4X4
Join Date: Aug 2009
Location: Vancouver BC
Posts: 270
I replaced my factory pedal because it was making funny clunk-clunk noises.
Went through no less than 3 aftermarket pedals that all failed after a few weeks. One actually lasted 3 months.
I am now running a new factory pedal and everything works perfect.

Sometimes it pays to stay with GM parts on certain critical components.
Reply With Quote Quick reply to this message
Old 09-04-2013, 08:51 AM
LisaPEI LisaPEI is offline
Junior Member
2003 GMC Envoy SLT XL
Summit White 4.2L I6 4X4
Join Date: Sep 2013
Location: St Peters PEI
Posts: 4

I have been having the same problem with my envoy for a few months now. Everything that I find says you HAVE to order OEM from dealership. NO ONE has had any luck with after market part. It will work for a month or two and then they end up replacing it. Everyone that has replaced with OEM from dealership says it's fixed the problem....On my way to the dealer tomorrow
Reply With Quote Quick reply to this message
Old 09-04-2013, 09:15 AM
dwright406's Avatar
dwright406 dwright406 is offline
Junior Member
2006 SAAB 9-7x
Black 5.3L V8 AWD
Join Date: Jan 2009
Location: Houston, TX
Posts: 84
When I had the same problems with my '02 Trailblazer, I ended up getting a pedal assembly out of a wrecked TB from the salvage yard for $30, never had a single problem again after that.

The bushing that the original pedal pivots on actually wore out, causing the rheostat to lose contact, tripping the code and reduced power.
Reply With Quote Quick reply to this message
Sponsored Links

reduced engine power

Quick Reply

Register Now

In order to be able to post messages on the Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum forums, you must first register.

Please enter your desired user name, your email address and other required details in the form below.
(Only letters, numbers, dashes and underscores are permitted for user names)
The user name that you choose is permanent and can never be changed.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Where you live (ex: Philadephia, PA)
Vehicle Year
Choose your year
Or enter your choice here:
Vehicle Color
Choose your factory color (Custom, Not Listed & Two-Tones; Use Text Field Below)
Or enter your choice here:
Vehicle Make
Choose your make
Or enter your choice here:
Vehicle Model
Choose your model
Or enter your choice here:
Vehicle Engine
Choose your engine
Vehicle Drivetrain
Choose your vehicle drivetrain
Security Question
Fill in the blanks: Tra___oy
Please select your insurance company (Optional)


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Thread Tools

Posting Rules
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

» Sponsors

Advertising Info

All times are GMT -4. The time now is 01:22 AM.

Chevy TrailBlazer and GMC Envoy Enthusiasts - Copyright 2004 - 2009 All Rights Reserved.
All trademarks referenced herein are property of their respective owners.
RSS Feed