HVAC Mode Door Stall

SYMPTOM
HVAC MODE DOOR STALL

WHEN MONITORED
With the ignition key on and battery voltage greater than 10 Volts.

SET CONDITION
The mode door fails to indicate a stall condition during motor calibration or during failed feedback calibration.

POSSIBLE CAUSES
- BCM HVAC Failure pretest
- HVAC control head - ground circuit open
- HVAC mode sense circuit open
- Mode door driver (+) circuit short to B+
- Mode door driver (-) circuit short to ground
- HVAC control head mode sense defective
- Mode door driver (+) circuit open
- Mode door driver (-) circuit open
- Mode door driver (-) circuit short to B+
- Mode door actuator drive defective
- Mode door actuator linkage bind
- BCM - mode door driver defective
- BCM - mode sense defective
- Mode door actuator default