CODE 21 - Throttle Position Sensor
Trouble Code 21 indicates that the Throttle Position Sensor (TPS) is reading abnormally high. TPS volts should be close to 0.42 V at closed throttle and rise smoothly in about 0.02 volt increments to a maximum reading of about 4.85 volts at WOT.
The conditions for setting this code are:
- or -
Note: During a Code 21 condition, the ECM uses a default TPS value of 2.6 volts. This will cause the engine to idle very high.
Typical causes for this code include: