Possible Causes
WARNING: This page is about a different car, the 2002 Nissan Pathfinder and 2002 Infiniti QX4. However, it is still accessible from the selected car via links, so may be relevant.
Malfunction "A" will cause ECM to illuminate MIL and set DTC P0121 when a high voltage from the TPS is sent to ECM under light load driving conditions.
Malfunction "B" will cause ECM to illuminate MIL and set DTC P0121 when a low voltage from the TPS is sent to ECM under heavy load driving conditions. Possible causes of malfunctions "A" and "B" are:
- Poor, loose, corroded or damaged terminal connections.
- TPS circuits open or shorted.
- Faulty fuel injector.
- Faulty Crankshaft Position (CKP) sensor (REF).
- Faulty CKP sensor (POS).
- Faulty MAF sensor.
- Intake air leaks.
- Faulty TPS.