Operation CHARM: Car repair manuals for everyone.

A/C Control A/C Switch Failure (MTC)

Tests 1 - 3:




Tests 4 - 8:




SYMPTOM
A/C CONTROL A/C SWITCH FAILURE (MANUAL A/C)

WHEN MONITORED
With the ignition ON.

SET CONDITION
The BCM detects the A/C switch stuck in the depressed position for at least 30 seconds.

POSSIBLE CAUSES
- Control head - short to ground
- Mode switch MUX circuit short to ground
- Mode switch MUX circuit short to sensor ground
- Body control module - mode switch MUX short to ground
- Control head - button sticks
- Control head - mode MUX incorrect
- Control head - open switch
- Control head switches okay