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Jason "Trickflow" Z
Jason "Trickflow" Z, Chevy Technician
Category: Chevy
Satisfied Customers: 9
Experience:  Performance Automotive shop owner for 12 years
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My 2002 trailblazers reduced engine power light and service

Resolved Question:

My 2002 trailblazer's reduced engine power light and service engine soon light when I am driving. I lose power and the tranny does not shift properly. I turn off the engine and restart it and it resets the the reduced engine power and I regain power but the service engine light stays on. If I don't push the accelerator to far I seem to be able to baby it and not lose power. What sensor has gone bad?
Submitted: 7 years ago.
Category: Chevy
Expert:  Jason "Trickflow" Z replied 7 years ago.

This is usually caused by a bad Accelerator Pedal Position Sensor (APP Sensor). It is located on a bracket above the accelerator (gas) pedal. If you need a replacement sensor the GM part # XXXXX ($120.05 list)




© 2008 Mitchell Repair Information Co., LLC.

Throttle Position (1) Volts


At Idle

APP Sensor No. 1 Less Than 1.1

APP Sensor No. 2 Greater Than 3.9

Wide Open Throttle

APP Sensor No. 1 Greater Than 2.0

APP Sensor No. 2 Less Than 3.0

(1) Measured at sensor or as seen on scan tool.

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