HVAC Mode Door Feedback Failures
NAME OF CODEMode Door Motor Feedback Too High/Low
WHEN MONITORED
With the ignition key on and battery voltage greater than 10 volts.
SET CONDITION
The feedback signal difference between the two ends of the door travel is not equal to or larger than a predetermined value during door calibration, or the feedback signal measured by the body control module is not within the calibrated range during normal operation.
THEORY OF OPERATION
During ATC calibration, the body control module drives the mode door fully to each end of its travel (defrost and panel) while monitoring feedback voltage. The feedback voltage at each end is recorded in body control module memory. During normal operation, the body control module monitors feedback voltage to determine door position.
POSSIBLE CAUSES
- Blocked door
- Open wire
- Broken linkage
- Grounded wire
- Broken mode wire
- Shorted wire