Operation CHARM: Car repair manuals for everyone.

Code 40 (A/C Compressor Signal)

A/C COMPRESSOR
Explanation
This trouble code is stored when the control unit simultaneously receives the signals 'compressor in operation' (Pin 40) and A/C switch not pressed' (Pin 41).

Troubleshooting
- Check wires to the Digital Motor Electronic (DME) control unit; break at Pin 41 and a short to battery voltage at pin 40.
- Proceed with displayed scan tool diagnostic instructions where applicable.