Reduced Engine Power - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

JeSSter · 01-17-2013, 01:54 PM

This gem came on during my drive home from work. Car still ran OK, trans downshifted kinda jerky (safe mode). Drove it to the dealer to check it. Code indicated a Accelerator Pedal Position sensor issue (didn't get the code). Service manager said I was out of warranty (69K) and this was not drive train (WTF?) Wanted me to leave it and Customer Pay for the work. Not gonna happen..........I can throw a lot of parts at it before it costs more than their hourly rate. Accelerator Pedal Position sensor is replaced by replacing the whole pedal ($61), three bolts and electrical connector.

When I restarted the car, ran normal again (still had check engine light). Drove out and stopped at the car wash on my way home (touchless). After leaving the wash, REP came on again......stopped and let it sit for a few minutes, started and ran normal. When I got home, got under the dash to press on the electrical connector in case anything came loose.

Driven it for two days now with no issues. If the connector was loose, maybe fixed. I will take it through the car wash again because the other variable is that a little more than a week ago, had windshield replaced. I have read that if the seal is not right, there could be water leaking on the electrical connectors, which could cause the REP. Anyone heard this happening?

JeSSter

jameslk55 · 01-17-2013, 02:47 PM

Sorry, nothing helpful to add other than damn, that's a lot of miles.

Juiced1 · 01-17-2013, 04:12 PM

Reduced engine power is extremely annoying! Usually, it's caused by some sort of short which can be next to impossible to find. I guarantee nothing is wrong with your pedal either. Hunt down all your main electrical connections and put a little bit of silicon on the back of the wires. That way if you do have a leak it'll keep em dry and reduce any possiblity of a short. If your windsheild was replaced I would look into that for sure as a possible leak too.

Mchlgrrsn · 01-17-2013, 04:23 PM

its called "limp mode" ... cpu doesnt like something, could be anything

SmokeScreen45th · 01-28-2013, 07:58 PM

Well mine came on tonight while at a stop. Took it to the dealership before it closed so I guess I'll find out tomorrow.

fastlane2010 · 01-28-2013, 09:09 PM

I have done them and it does fix them but i have also had the throttle body give a false code of app sensor put the pedal on and clean the throtle body your problem will go away

SmokeScreen45th · 01-29-2013, 11:36 AM

Dealer called.... Said they're upgrading the firmware in ECU and some of the harness plugs. I get the ECU but anyone know of an upgrade to wiring harness plugs?

Chevrolet Customer Svc · 01-29-2013, 01:12 PM

Quote:

Originally Posted by SmokeScreen45th

Well mine came on tonight while at a stop. Took it to the dealership before it closed so I guess I'll find out tomorrow.

What were they able to find out for you regarding this message? Please let us know.

Brandon
Chevrolet Customer Service

SmokeScreen45th · 01-29-2013, 01:16 PM

Brandon,

See post above. Also the Dealer said the codes that popped were P0442 & P0191. Said its a small evap leak. Car will be ready today.

bkscott · 01-29-2013, 02:07 PM

I had that a few weeks ago. Dealer claimed it was my ported TB. Replaced with a stock one, and so far all is well. They also reflashed the computer. My gas mileage went up about 2 mpg. I will eventually put the TB back on to see if that was really the problem.

DJ_BigC · 01-29-2013, 08:39 PM

The most common code for the APP sensor going bad and causing the car to go in limp mode is a P2138. APP sensor 1-2 correlation.

Theres two sensors inside ur accelerator pedal, they both need to read the same voltage at all times, when the dont correlate, it flags the car into limp mode. 99% of the time the car needs an accelerator pedal assembly, it's just a matter of time until the light stay on permanently. 3 bolts to remove a reinstal the new assembly just plug it in and go no programming required.

I can say with 100% certainty that your problem is not a loose connection at the pedal assembly.

DJ_BigC · 01-29-2013, 08:44 PM

And for you throttle body guys, the vehicle usually sets a P2135 throttle position sensor 1-2 correlation. Same deal, 99% of the time it usually needs a new TB sensor on some models, on others it's the whole TB assembly. This repair usually requires a reflash of the ECM with a updated calibration. This code also causes the vehicle to go into limp mode.

** I'm not saying that this is the fix for all vehicles I would need to diagnose it to confirm 100%.

JeSSter · 01-31-2013, 10:13 AM

Update: took the pedal assembly out and unplugged it. Checked plug, and pushed in wires. Reasssmbled. Ran for 6 days with no code (it was a P2138). On the sixth day, code was now P2122. Cleared that, and it came on again same day. Called dealer and ordered new pedal assy. On drive to dealer from work to pick up the pedal, light came on again. Stopped at dealer to pick up. Took about half and hour to get in and out of dealer, so I figured the light would be clear (would still have check engine) and drive home would be normal. Reduced Engine Power was still on. Read code at home and there was 2 (P2138, and P2122). Put the new pedal on and cleared codes. Drove around a bit and to work this morning, no codes yet. It probably really was the pedal this time.......

AiRDawG · 02-04-2013, 12:58 PM

Interesting thread. Very similar problem has been bothering my car for the past month and a half. Seemingly randomly will go into limp mode, giving a gamut of DTCs each time. I can use HPT to clear them out and everything is absolutely fine for another day or so, then CEL comes back on, then a few days later it will drop to reduced engine power mode.

Dealer diagnosed it as a TB problem, but only did a cleaning and it seemed fine for a week or so, then problems started coming back.

If I have the laptop with me, I can clear the DTCs out on the fly for instant gratification, but I always try to get the ignition shut off as soon as possible when it goes to limp mode. If it sits for a while (as short as 10 mins) it will start back up in normal power mode.

Here's a DTC dump from HPT, which I collected the last time it went into reduced power mode:

[] P0121 - TP Sensor Circuit Insufficient Activity (Old) (Immature)
[] P013E - HO2S Delayed Response - Rich to Lean Bank 1 Sensor 2 (SES) (Old) (History) (Immature)
[] P014A - HO2S Delayed Response - Rich to Lean Bank 2 Sensor 2 (SES) (Old) (History) (Immature)
[] P1133 - HO2S Insufficient Switching Bank 1 Sensor 1 (SES) (Old) (History) (Current) (Immature)
[] P2135 - Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation (SES) (Pending) (History) (Immature)
[] P014A - HO2S Delayed Response - Rich to Lean Bank 2 Sensor 2
[] P1133 - HO2S Insufficient Switching Bank 1 Sensor 1
[] P2135 - Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation
[] P013E - HO2S Delayed Response - Rich to Lean Bank 1 Sensor 2

01-17-2013, 01:54 PM	#1
JeSSter Drives: 2011 RS/SS Cyber Gray Metallic Join Date: Nov 2010 Location: Michigan Posts: 129	Reduced Engine Power This gem came on during my drive home from work. Car still ran OK, trans downshifted kinda jerky (safe mode). Drove it to the dealer to check it. Code indicated a Accelerator Pedal Position sensor issue (didn't get the code). Service manager said I was out of warranty (69K) and this was not drive train (WTF?) Wanted me to leave it and Customer Pay for the work. Not gonna happen..........I can throw a lot of parts at it before it costs more than their hourly rate. Accelerator Pedal Position sensor is replaced by replacing the whole pedal ($61), three bolts and electrical connector. When I restarted the car, ran normal again (still had check engine light). Drove out and stopped at the car wash on my way home (touchless). After leaving the wash, REP came on again......stopped and let it sit for a few minutes, started and ran normal. When I got home, got under the dash to press on the electrical connector in case anything came loose. Driven it for two days now with no issues. If the connector was loose, maybe fixed. I will take it through the car wash again because the other variable is that a little more than a week ago, had windshield replaced. I have read that if the seal is not right, there could be water leaking on the electrical connectors, which could cause the REP. Anyone heard this happening? JeSSter

01-17-2013, 04:23 PM	#4
Mchlgrrsn Stroked and blown Drives: 2010 LS3 2SS Join Date: Dec 2012 Location: Bridgewater, NJ Posts: 1,458 View My Garage	its called "limp mode" ... cpu doesnt like something, could be anything __________________ LME 416 LS3 shortblock/Callies Compstar 4340 4"crank/Callies 6.125 H beams rods/Wiesco 4.07 forged pistons/Cam Motion custom LS1/LME ported heads /maggie TVS2300/I West 8rib 10%OD /3.2 pulley/OD cog drive/JRE tensioner/ID850 /ADM dual fuel/Kooks LT 1 7/8/magna flow2.5 /cat delete/Roto Fab CAI /MGW short throw /SPEC super twin clutch/G Force built trans,carbon syncro rear shaft upgrade /DSS 9"single CF DS /Strange 3.70/31 spline trutrac/MT DR's/earls oil cooler /tuned KHC

01-28-2013, 09:09 PM	#6
fastlane2010 Drives: 2010 camaro with fast lane stage 2 Join Date: Apr 2011 Location: hagerstown Posts: 705	I have done them and it does fix them but i have also had the throttle body give a false code of app sensor put the pedal on and clean the throtle body your problem will go away __________________ 12.4 in 1/4 at 117mph first time custom 2tone paint fastlane stage 2 hydroformed carbon fiber cowl and cluster kooks headers and 3" xpipe with pypes axle back

01-29-2013, 02:07 PM	#10
bkscott Drives: 2010 Camaro 2SS/RS Join Date: Dec 2009 Location: Grand Prairie, Texas Posts: 1,609 View My Garage	I had that a few weeks ago. Dealer claimed it was my ported TB. Replaced with a stock one, and so far all is well. They also reflashed the computer. My gas mileage went up about 2 mpg. I will eventually put the TB back on to see if that was really the problem. __________________ 94 Firebird Formula (Drowned 08/30/05) 2010 IBM 2SS/RS 6M Arrived 3/25/10. ADM CAI, Borla Type S Cat Back, VMAX Ported TB, LG Short Throw Shifter, 1LE Shocks, Hotchkis Sway Bars, Whiteline Cradle Bushing Inserts, Custom Powdercoated ZL1's ,Michelin Pilot Supersports, Stainless Power Headers, Solo J Pipes, AAC LED Sidemarkers, ZL1 Rockers, SLP Splitter, ADM Stage II Cam,ZL1 Diffuser,Vitesse Throttle Controller.

02-04-2013, 12:58 PM	#14
AiRDawG Drives: 2011 Camaro 2SS Join Date: May 2011 Location: Maryland Posts: 232 View My Garage	Interesting thread. Very similar problem has been bothering my car for the past month and a half. Seemingly randomly will go into limp mode, giving a gamut of DTCs each time. I can use HPT to clear them out and everything is absolutely fine for another day or so, then CEL comes back on, then a few days later it will drop to reduced engine power mode. Dealer diagnosed it as a TB problem, but only did a cleaning and it seemed fine for a week or so, then problems started coming back. If I have the laptop with me, I can clear the DTCs out on the fly for instant gratification, but I always try to get the ignition shut off as soon as possible when it goes to limp mode. If it sits for a while (as short as 10 mins) it will start back up in normal power mode. Here's a DTC dump from HPT, which I collected the last time it went into reduced power mode: [] P0121 - TP Sensor Circuit Insufficient Activity (Old) (Immature) [] P013E - HO2S Delayed Response - Rich to Lean Bank 1 Sensor 2 (SES) (Old) (History) (Immature) [] P014A - HO2S Delayed Response - Rich to Lean Bank 2 Sensor 2 (SES) (Old) (History) (Immature) [] P1133 - HO2S Insufficient Switching Bank 1 Sensor 1 (SES) (Old) (History) (Current) (Immature) [] P2135 - Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation (SES) (Pending) (History) (Immature) [] P014A - HO2S Delayed Response - Rich to Lean Bank 2 Sensor 2 [] P1133 - HO2S Insufficient Switching Bank 1 Sensor 1 [] P2135 - Throttle/Pedal Position Sensor/Switch A/B Voltage Correlation [] P013E - HO2S Delayed Response - Rich to Lean Bank 1 Sensor 2 __________________ My build thread

01-17-2013, 02:47 PM	#2
jameslk55 Drives: 2012 2LT/RS, 2005 SLK55 AMG Join Date: Jul 2012 Location: Falls Church, VA Posts: 1,163	Sorry, nothing helpful to add other than damn, that's a lot of miles.

01-17-2013, 04:12 PM	#3
Juiced1 Account Suspended Drives: 2012 2SS CAMARO 45th Join Date: Apr 2011 Location: St. Charles, IL Posts: 18,648	Reduced engine power is extremely annoying! Usually, it's caused by some sort of short which can be next to impossible to find. I guarantee nothing is wrong with your pedal either. Hunt down all your main electrical connections and put a little bit of silicon on the back of the wires. That way if you do have a leak it'll keep em dry and reduce any possiblity of a short. If your windsheild was replaced I would look into that for sure as a possible leak too.

01-28-2013, 07:58 PM	#5
SmokeScreen45th Drives: 2012 2LT 45th Anniversary Join Date: Jul 2011 Location: Houston Texas Posts: 188	Well mine came on tonight while at a stop. Took it to the dealership before it closed so I guess I'll find out tomorrow.

01-29-2013, 11:36 AM	#7
SmokeScreen45th Drives: 2012 2LT 45th Anniversary Join Date: Jul 2011 Location: Houston Texas Posts: 188	Dealer called.... Said they're upgrading the firmware in ECU and some of the harness plugs. I get the ECU but anyone know of an upgrade to wiring harness plugs?

01-29-2013, 01:16 PM	#9
SmokeScreen45th Drives: 2012 2LT 45th Anniversary Join Date: Jul 2011 Location: Houston Texas Posts: 188	Brandon, See post above. Also the Dealer said the codes that popped were P0442 & P0191. Said its a small evap leak. Car will be ready today.

01-29-2013, 08:39 PM	#11
DJ_BigC Rockin' Steady Drives: 2010 Camaro 2SS Join Date: Apr 2012 Location: Timmins Posts: 216	The most common code for the APP sensor going bad and causing the car to go in limp mode is a P2138. APP sensor 1-2 correlation. Theres two sensors inside ur accelerator pedal, they both need to read the same voltage at all times, when the dont correlate, it flags the car into limp mode. 99% of the time the car needs an accelerator pedal assembly, it's just a matter of time until the light stay on permanently. 3 bolts to remove a reinstal the new assembly just plug it in and go no programming required. I can say with 100% certainty that your problem is not a loose connection at the pedal assembly.

01-29-2013, 08:44 PM	#12
DJ_BigC Rockin' Steady Drives: 2010 Camaro 2SS Join Date: Apr 2012 Location: Timmins Posts: 216	And for you throttle body guys, the vehicle usually sets a P2135 throttle position sensor 1-2 correlation. Same deal, 99% of the time it usually needs a new TB sensor on some models, on others it's the whole TB assembly. This repair usually requires a reflash of the ECM with a updated calibration. This code also causes the vehicle to go into limp mode. ** I'm not saying that this is the fix for all vehicles I would need to diagnose it to confirm 100%.

01-31-2013, 10:13 AM	#13
JeSSter Drives: 2011 RS/SS Cyber Gray Metallic Join Date: Nov 2010 Location: Michigan Posts: 129	Update: took the pedal assembly out and unplugged it. Checked plug, and pushed in wires. Reasssmbled. Ran for 6 days with no code (it was a P2138). On the sixth day, code was now P2122. Cleared that, and it came on again same day. Called dealer and ordered new pedal assy. On drive to dealer from work to pick up the pedal, light came on again. Stopped at dealer to pick up. Took about half and hour to get in and out of dealer, so I figured the light would be clear (would still have check engine) and drive home would be normal. Reduced Engine Power was still on. Read code at home and there was 2 (P2138, and P2122). Put the new pedal on and cleared codes. Drove around a bit and to work this morning, no codes yet. It probably really was the pedal this time.......