BrewDay09

I had a track day this weekend and during the third session I got a CEL for TPS Circuit Low Voltage (P1022). It didn't affect the running of the engine on track but it did idle at about 1500 rpm when I came back into the paddock. I was able to reset it through OBD2 which also corrected the idle and it stayed off until I went back to full speed on track. Each successive session saw it appear sometime during the first or second lap, again with no symptoms. I reset it between each session and continued on my way. On my drive home it never reappeared.

Per the service manual I checked the throttle position at closed and WOT with the OBD2 and both were normal (6.3% and 88.9%). I also checked the voltage and resistance across the connector and sensor terminals. Again all in spec. I then ran it through the full range throttle with the OBD2 connected and found one spot where it dropped down to -0.4% where it should have been about 8%. Seems like this could be it. However, I started the car and ran it at this throttle position for about 15-20 seconds and was not able to reproduce the CEL.

Is this just a bad TPS or should I be looking for something else? Search results for this CEL code seem to be accompanied by several other codes which I did not get.

The previous owner replaced the TPS at some point with an aftermarket unit since the flanges have been buzzed with a Dremel. Not sure which brand/model. Is the Omnipower unit still the aftermarket replacement of choice?

Thanks in advance.

Billman250

Very likely TPS. Can you post the feeeze data?

I wonder what an OEM TB goes for these days...

BrewDay09

Thank you for the response Bill.

Will the freeze frame data still be stored even though I cleared the CEL? If so, I will see if I can get it through the Torque app and bluetooth scanner I am using.

BTW. Majestic sells the new throttle body for $610. Ouch. That's pretty steep for a new potentiometer.

Billman250

Freeze data is gone.

BrewDay09

Ok. When the CEL returns, I'll capture the freeze data and share it.

BrewDay09

Thought I should update and (hopefully) close out this thread.

During the last 4 months of spirited street driving, the TPS CEL never came back. I also ran another track day this weekend and the TPS issue did not show itself there either.

To recap, I got repeated CELs on track for TPS circuit low voltage in May, which could be reset but eventually came back. I cleaned and calibrated the TPS and put dielectric grease on the contacts. No occurrences since then.