Note On Intermittents

If Code E21 is intermittent, manipulate related wiring while observing ECM parameter P.0.1. Check TPS and TPS test point connectors for shorts to voltage.

Cycle TPS through its travel and tap on TPS with a pencil or pocket screwdriver to test for intermittent TPS. If fault is induced, the parameter will skip to a high throttle angle.

Fig 1: Code E21 Schematic - Shorted Throttle Position Sensor Circuit

Fig 2: Code E21 Flow Chart - Shorted Throttle Position Sensor Circuit