CEL on, codes p0122 & p0123, try to clear codes and 122 clears 123 will not clear. Vehicle runs terrible, hesitates, trans doesn't seem to shift at correct points, sometimes almost stalls, idle rpm will jump to 1500 rpm and then settle down to 750 or so. I have another almost identical Jeep (different color), so I swap out the TPS.
No change. And the TPS works fine in my other vehicle. Notice that the cruise control will not work, light on dash comes on but the cruise will not engage. Decided to swap out clockspring. No change. The clock spring works fine in other vehicle.
The vehicle had an open air bag recall that needed to be taken care of, so I called dealer made appt. For the recall knowing he would have to put DRB111 scan tool on to check safety system when he was done with recall repair. I asked him to check P0123 code while he had tool hooked up. He came back and said the connector on the TPS was cracked and that was what was causing the problem. I was skeptical to say the least and even more so when he told me he wanted $268.00 to change the connector. So I went to another dealer and bought a new TPS connector and soldered it in place. No change on the p123 code and I still cannot clear the code. With FSM in hand traced out the circuits and decided to disconnect the horn and cruise control connector from the clock spring. (Note horn worked before I disconnected) I was now able to clear the P0123 code, drove the vehicle and it drives perfectly. But with limited electrical capability I don't know what to do next. I know the IAC, MAP, TPS, CKP, CMP, sensors all seem to be tied to the same 5-volt supply from PCM and the grounds I believe are common also. I just don't know where to start to find the bad wire or wires or confirm one of the cruise control switches is the culprit. Any guidance would be appreciated.
Friday, March 14th, 2014 AT 9:40 AM