Service Throttle Control

You have a problem with the electronic throttle control . You need to have it checked for codes , could be a few different thing's Pt 1 2007 Chevy 2500HD Reduced Engine Power Warning Fault Code P1516... P2138 APPS Accelerator Pedal Position Sensor Fix 3 5L Chevrolet Impala Lot's of codes for this , Drive by Wire Function and diagnostics by Wells

There are a few reasons this might happen. Believe it or not it could be as simple as a loose gas cap. That can cause a false reading in the throttle position sensor, and activate the traction control. Remove the gas cap and put it back on making sure to tighten it until it "clicks". Another reason may be a faulty throttle position sensor, or it has a glitch, thus activating thr traction control. Try the "Old Fashioned" fix of disconnecting the battery for about an hour, to reset the computer. After you reconnect it, turn the key to the ON position but don't start it. Slowly press the accellerator to the floor and release. Turn the key back off, wait a few seconds then start the car. This should take care of the glitch, if not it's most likely the throttle position sensor needs to be replaced.

More than likely a brake pad,or pads holding on rotor.This can be a bad caliper or bad caliper brake hose.

Reduced power is a problem with electronic throttle contol . drive by wire . Do you know what this is ? Taking the vehicle an having it hooked up to diagnostic tool an checking for DTC'S - diagnostic trouble codes is always a first step when trying to find the root cause of any trouble light ! And not auto zone , pep boys , or advance auto parts . Thier diagnostic tool will not check codes in all system control modules .

It is the APP sensors , Your vehicle has electronic throttle control . P2122 Throttle Pedal Position Sensor Switch Circuit Low Your best bet would be to take it to a qualified repair shop .

These are not codes , they are warning lights , telling you the driver that a problem exist . code says, traction control off,next code says ,service stabilitrak and the last code says...engine power reduced. DTC'S - diagnostic trouble codes could be stored in the control modules that control these system's . The main problem is more then likely with the reduced engine power. This is because of a problem with the electronic throttle control system . This problem will turn off these other thing's , turning on their light's .
Throttle Actuator Control (TAC) System Description
All newer vehicles have this ! There are position sensors in the Gas pedal and on the throttle body on the engine , The computer uses a DC volt electric motor to make the vehicle go . The sensors wear over time , the motor can wear , wiring can break etc...
Reduced Engine Power Mode
When the ECM detects a condition with the TAC system, the ECM may enter a reduced engine power mode. Reduced engine power may cause one or more of the following conditions:
• Acceleration limiting--The ECM will continue to use the accelerator pedal for throttle control; however, the vehicle acceleration is limited.
• Limited throttle mode--The ECM will continue to use the accelerator pedal for throttle control; however, the maximum throttle opening is limited.
• Throttle default mode--The ECM will turn off the throttle actuator motor and the throttle will return to the spring loaded default position.
• Forced idle mode--The ECM will perform the following actions:
- Limit engine speed to idle by positioning the throttle position, or by controlling the fuel and spark if the throttle is turned off.
- Ignore the accelerator pedal input.
• Engine shutdown mode--The ECM will disable fuel and de-energize the throttle actuator.
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I work at a chevy dealer an can not believe the one you took it to can't find the problem . Where is this dealer ? I will have a long talk with my district rep.
Drive by Wire Function and diagnostics by Wells

Start with testing the ABS system. Sounds like a wheel sensor is giving out bad signals. The vehicle is no longer under warranty?

I know this is not a solution but I too started having this same problem today. Start car, runs normal then all the sudden it feels funny, traction control light blinks on and dash displays service traction control-reduced engine power. This causes my car to sputter like it is going to stall I have to pull over and turn my car off and back on to drive off (only for it to do it within the next 10 minutes). I thought turning TC off would work for now just to drive it, no not successful stil does it : ( I TOOK IT TO AUTO ZONE AND HAD IT SCANNED HAD A CODE FOR GROSS EVAC LEAK AND SOMETHING ABOUT THE THROTTLE PLATE/BODY NOT SURE IF THAT IS RELATED BUT THAT ALL THE INFO I HAVE ON THAT.

po455 is Probable Cause[s]

1. Defective, loose or missing fuel cap
2. EVAP canister broke, hose cracked or not connected
3. Purge or vent solenoid defective
4 . Vacuum leak at engine po121 code po121 means Throttle Position Sensor/Switch A Circuit Range/Performance Problem . it is usually indicative of a faulty throttle position sensor or faulty wiring harness in the engine bay.

how do you fix the "reduced engine power" light on the dash bard of a 07 Chevy Impala LTZ and "Service Traction Control"?