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Chevy Impala "REDUCED ENGINE POWER" message



  • gmcustsvcgmcustsvc Posts: 4,055
    Sorry for my misunderstanding!

    If you want for us to check into this further, if for nothing else than further documentation, please don't hesitate to contact us at (include your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation).

    Sarah, GM Customer Service
  • My 2008 outlook 8J118867 has left me stranded twice this last week. I get a computer message of traction control off and much reduced power. Out of desperation I have discovered if I turn off the car, it can “reset” itself and go back into drive mode with a check engine signal. The codes given are:
    P1516 Electronic throttle mod VS, Throttle Position Performance
    P2119 Throttle Closed Position Performance
    P2135 TP Sensor 1-2 Correlation
    It needs to be fixed quickly as I live in a mountainous area and I literally “get stuck” with my two young girls.

    My trusted mechanic owns Sabaru here in Colorado springs. We have not had the best of luck going to dealers here and in Denver. We had transmission replaced when we were stranded near Denver and had to push car off the road (literally). It was amazing that it was replaced “no questions asked’ and the dealer there admitted they had to replace “a lot”. That told us that the car brand was having lots of problems.

    Our local dealership is: Mike Shaw GM 1313 Motor City Dr 719-636-3881. This is the same place that argued with us about our headlight problems and then after we paid to have them fixed at a cheaper shop, a month later the recall went out about the light connectors.

    Right now it is sitting at Sabaru Repair (they have been AWESOME on our subarus and I trust them totally) and Martin and I are researching the problem – and I came upon this website.
    Please let us know what GM is doing about this problem. Thank you-
    Brenda S
  • gmcustsvcgmcustsvc Posts: 4,055
    Looking at your VIN, outlook2008, your powertrain warranty expires today (unless you're mileage is already past 100,420 MI). I understand you have a good relationship with your mechanic, but if you had wanted to see if what's happening with your vehicle would be covered it would be better to act on that sooner rather than later.

    Sarah, GM Customer Service
  • hi. i have a 2010 chevy impala. they are GARBAGE. service light came on when i left chevy dealer ship. they are saying nothing they can do since i left their property. i have no service warranties they say.. i was sold garbage. now i get the same message everyone is getting service traction control engine powering down. i was driving 2 days ago and it came on i went to pull over to shut vehicle off. it seems to work for a bit. as i went to turn. steering locked brakes and gas peddle went stiff. i had no control of the car went into opposing lane. and stopped. that scared the living day lights out of me. i could have been killed. i dont know what to do. i need help.. i drive granddaughter back and fourth and scared to dealth only vehicle i have. i need it for job. i only had this garbage a yr and half. nothing but headached. will NEVER BUY A NOTHER CHEVY AGAIN. THOSE PPL SHOULD BE SUED.
  • Funny story, Dealership diagnosed my car as having a bad throttle body, replaced it, still got the p2135 throttle position sensor error, dealership was stumped and said anymore poking around would start costing me money. so My dad said I'll be there to pick it up. While he was there, he picked up a wiring diagram for the throttle body harness to check ourselves since it doesn't cost us 60-100$ an hour whatever labor cost is these days. He voltage tested two wires in the harness i don't know which but the voltage was 11 almost 12 volts, which is full battery voltage... that's a lot higher than normal 4.5ish or something I read it should be... so the garage suggested I get a new battery, I had the original AC Delco battery that came with the car so it's 4-5 years old, we have a spare lying around we connected the spare and the voltage dropped to normal levels. So fingers crossed a bad battery and a possible bad throttle body caused my problem. I have no idea if the throttle body was the issue as even after they replaced it, it threw the voltage code pertaining to the Throttle position sensors, we're gonna give it a few days and see if the new battery fixes it, otherwise we have to chase electrical gremlins as they are not covered under GM's warranty when your bumper to bumper runs out. I will keep you all posted. Fingers crossed!
  • gmcustsvcgmcustsvc Posts: 4,055
    What is the mileage on your Impala, christine68?

    Sarah, GM Customer Service
  • I have a 2006 chevy impala and my service throttle control and reduce engine power lights keep coming on!! I have had a something replaced on the gas pedal already (cant remember what) it was good for a while now its doing it everyday!!! I can pull over and cut the car off and some times it fixes the problem. It is sooooo aggrivating only going 40 mph i am scared I'm gonna cause a wreck!! I have noticed my car heater will not heat up while its in idle.are the two connected? I dont know what to do
  • gmcustsvcgmcustsvc Posts: 4,055

    We're sorry to hear that you don't feel safe in your vehicle. Are you at all considering working with a GM dealership to get this looked into? Let us know if we can be of any assistance in that process! We can be reached at (include your name and contact information, the last 8 digits of your VIN and mileage, and a summary of the situation).

    Sarah, GM Customer Service
  • Man so many replies top this message, my impala has 44,000 miles and is a 2009. Seem to be different fixes for same message. Unless I'm misreading. So a little confused. Replies would be welcomed. This is a scary thing to happen driving anywhere. My dealership is one that went by by. So not much help, was purchased new late Oct of 09.
  • trumble09trumble09 Posts: 13
    edited February 2013
    Depending on the code your car is throwing when it goes into Reduced Engine Power it can be several different fixes... P2138- Accelerator Pedal Position seems to indicate a bad Gas Pedal Sensor(Which isn't covered outside of the 3 year 36k bumper to bumper), P2135 a throttle body problem, more specifically Throttle Position sensors not agreeing on a voltage. So have your codes read at the dealer or an Auto parts store (usually for free) and it will indicate which problem you're having... my 2009 was throwing a throttle body code and the dealer replaced mine for free under the 100k mile Powertrain warranty, after 2009 they removed it from the powertrain warranty. After replacing the throttle body it still persisted, so We've kind of narrowed it down to a bad battery or bad wiring to the throttle body. If you've read previous posts the gas pedal is an easy 70$ self-fix that involves removing some bolts, plugging the new pedal in and putting the bolts back. I would go get a free scan at a parts store before taking it to the dealer, as my diagnostic fee at the dealer runs 100$.
  • i am having same issue with my 2010 chevy impala. i contacted gm dealer headoffice told them if i get killed or someone else ill sue them for everypenny> i have contacted a lawyer he said i got strong case. they sell these iece of [non-permissible content removed] and there is so many ppl on saying same thing happening to their impalas.they are ignoring it only want the money if will be funny when they have none.when ppl sue them
  • jlg7jlg7 Posts: 16
    Im having the same problem with my Chevy Traverse. GM really needs to step up to the plate and do a recall on this issue before someone gets killed in an accident. Same problem seems to be happening in the Saturn cars and Equinox too! Hey GM since you monitor these boards, YOU need to fix this problem now!!!!! :lemon:

    I have the same promlem, mine is included with Traction control needs service.
    for icy weather, when its warm no problems but suxx in the winter I love my chevy but dont know what to do went to garage change wheel bearing but came back shortly after
  • lil100lil100 Posts: 12
    Now I am having trouble again with my Impala - just had the gas pedal replaced - now apparently it's the gas caps or something. This is ridiculous. I think I"m going to write a letter to write letters to newspapers and tv news shows. If GM is not going to do anything - we need to start doing something.
    Very unhappy.
  • trumble09trumble09 Posts: 13
    edited February 2013
    Battery didn't help after a weekend test drive "Reduced Engine Power/Service Throttle" were back, My dad started tracing wiring and found this in the PCM Box.

    PCM Pic 1
    PCM Pic 2
    PCM Pic 3

    The Blue in the terminal is a bunch of Icemelt salt that had found its way into the airbox with water and rode the wires down into the PCM plug and corroded some terminals, including the Throttle body wire connection. He cleaned the terminals with air and got the corrosion off them and the gunk out of the plug and got the moisture out and for 3 days my car has been running with no hiccups even when the traction control has kicked on a bunch of times on slick snowy roads (which caused the reduced engine power before) The PCM is located in the bottom of the airbox as it requires air to cool it, although it doesn't require salt. Someone who owned the car before me apparently had the PCM box off ripped a gasket and put it back on with half a gasket. Luckily so far it doesn't seem like permanent damage was done to the PCM.
  • gmcustsvcgmcustsvc Posts: 4,055
    Hello dandd2009,

    If you need assistance locating another dealership in your area to get this looked into, please let us know! Send us an email at with your request and ZIP code.

    Sarah, GM Customer Service
  • gmcustsvcgmcustsvc Posts: 4,055
    Good morning newhaven,
    Was your garage one of our GM dealerships? If so, we'd be happy to follow up on your visit there. Please email us at (include your name and contact information, the last 8 digits of your VIN and mileage, and as summary of the situation so far).

    Sarah, GM Customer Service
  • I have a 2011 Chevy Impala LT, I have been experiencing 3 messages SERVICE STABILITRAK, SERVICE TRACTION CONTROL AND REDUCING ENGINE POWER. This has been going on for months and the dealership wants to charge $129.00 for diagnostic. I took it to Autozone and got it for free. Just as I suspected that the Throttle Position Sensor (TPS) is broken or burned out. I also did a google search and found that many others are having the very same problem. The car would jerk and downshift. This morning I also received another message after I pulled over, STARTER DIABLED, SERVICE THROTTLE. I had to wait for minutes before starting again and 15-25 min there after.
  • Look at my posts above I had the same issue, my throttle body was covered under the powertrain warranty but after 2009 they removed it. If you're still in bumper to bumper it may be covered, if not you can review other posts for cost of a replacement throttle body. They replaced my throttle body and it persisted. Other possible causes for the throttle body code include a bad throttle body wiring harness, or a gunked up PCM plug like we found in my car.
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