Code 51, No A/C Signal: Notes
The A/C amplifier supplies a signal to the ECM when A/C is selected. This signal allows the ECM to adjust engine speed to compensate for additional load on engine. Code 51 will set if this signal is not present.
NOTE:
Test numbers refer to test numbers on diagnostic chart.
- This determines that a signal is being sent from the A/C switch.
- This determines that A/C amplifier is sending a signal to the ECM (VIN 5) or if A/C amplifier is sending signal to the A/C clutch relay (VIN 6).