Codes P1515 and C0235

CASSANDRA JOY HOLLINS

MEMBER
2003 CHEVROLET TRAILBLAZER
4.2L
V6
4WD
AUTOMATIC
250,000 MILES

My husband was driving it one day and it just quit running and wouldn't start back. We pulled it home and tried starting it when we turned the key over the gauges started jumping up and down and the key got stuck in the ignition. I hooked up a tester and it read code P1515 TP Sensor to MAF Sensor Correlation it also read ABS antilock brake system, C0235 left rear wheel speed signal circuit open. I bought a used throttle body and changed it but nothing changed? What else could be wrong?

1 Reply

KASEKENNY

MECHANIC
18,907 POSTS

This P1515 code is telling you that the throttle position is not in its expected position based on what the accelerator pedal position sensor is telling the PCM.

In other words, when you press the accelerator pedal it expect the throttle position to tell it the same info that the throttle blade in the throttle body has moved there. When they are not in that expected range it sets the code.

The speed sensor code is not causing this so we can address that later if it is still there. However, if the ABS light is not on the I suspect that was an issue but the code is stored and no longer an issue.

I attached the testing for the P1515 for us to run through and I suspect there will be a circuit issue so let's run through this testing and go from there.

Here is a guide that will help with this:

https://www.2carpros.com/articles/how-to-check-wiring

Images (Click to make bigger)