DDEC III/IV Single ECM Troubleshooting – Section 21.1 Description of Flash Code 21

Section 21.1
Description of Flash Code 21

Flash Code 21 indicates that the Throttle Position Sensor (TPS), see Figure "Throttle Position Sensor " , input to the ECM has exceeded 95% (normally >4.75 volts) of the sensor supply voltage.‪

This diagnostic condition is typically:‪

  • Open sensor return circuit
  • Sensor signal circuit is shorted to the sensor +5 volt supply


DDEC III/IV Single ECM Troubleshooting Guide - 6SE497
Generated on 10-13-2008

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