reduced engine power

[cnowlin]

I have a 2005 pontiac grand pix that has been giving me the reduced engine power signal. i took it in to have the codes read and it gives me codes p1125 and p2138. someone suggested i clean the throttle plate which helped for awhile, but its doing it again.any suggestions on how i should go about fixing this.

[GTP Dad]

Welcome to AF!!

The one code the P1125 indicates that the throttle position sensor is probably going bad. I would replace it after cleaning the throttle body. A good cleaning can't hurt. The throttle position sensor tells the computer to send fuel to the engine. If the tps is not working correctly it doesn't send a correct signal and the engine doesn't get the required fuel to make power. As for the other code, I can't find a reference that will give me an explanation so maybe someone else can help with that one.

[BNaylor]

It would help to post what engine. The '04 and up technically DO NOT have a throttle position sensor (TPS) like the previous generation '97 - '03. It is "drive by wire" and a control module (TAC - Throttle Actuator Control) at the throttle body throttle plate.

DTC P2138 like the P1125 is an Accelerator Pedal Position Error (APP).


BTW - GM has various TSBs out on "drive by wire" issues so a trip to the dealership may be necessary.

[cnowlin]

I have v6 05 pontiac grand prix. i did have someone order a new accelerator pedal to change out and the car felt alot better when driving. of course it did end up shutting off again and gave the same codes.