Diagnostic Aids

A skewed MAP sensor may cause this DTC to set. If the TP sensor is operating properly, and if this DTC continues to set, test the MAP sensor for proper operation.

The PCM 5-volt reference circuits are internally connected within the PCM. If all the TP sensor circuits are okay, inspect the MAP sensor for malfunctions.

If DTC P0121 is intermittent, see DTC P1121: TP SENSOR CIRCUIT - INTERMITTENT HIGH VOLTAGE .