P2138 GMC - 2007 sierra 1500 4.8 engine

Question

I can erase the code p2138 sometimes but then it comes back on after i let it set for a while or the last time it came on when i got off the freway and came up to the stop light. The trans shift real hard from first to second but not in the other gears. It also has reduce engine power on dash read out and its has no power when it on. What causes this problem

Answer 1

Hi there

This code is for the accelerator pedal position sensor.

Usually its a problem with the APP sensor, however bad wiring or a problem with the throttle actuator can cause the code as well. 

P2138 GMC - Accelerator Pedal Position Sensor 1-2 Correlation

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