Blend Door Control Circuit/Performance (MTC)

B104C-BLEND DOOR CONTROL CIRCUIT/PERFORMANCE (MTC)


Theory of Operation
The A/C Heater Control monitors the door driver circuits during actuator operation for shorts to ground, shorts to battery, and shorts to other door driver circuits. If detected, the A/C Heater Control reports these types of faults as Control Circuit/Performance DTCs. It is important to note that Control Circuit/Performance DTCs do not indicate where or what type of short is present and that additional system testing is necessary to provide more details about the reported fault.

WHEN MONITORED
With the ignition on.

SET CONDITION
If the A/C Heater Control detects a short on any of the door driver circuits while attempting to drive this actuator. This DTC has a maturing time of 5 seconds and a de-maturing time of 10 seconds. If the DTC's status changes from active to stored, it will stay in memory for 100 ignition cycles.

POSSIBLE CAUSES
- Door driver circuit(s) shorted

NOTE: The DTC must be active for the results of this test to be valid. Do not perform this test if the DTC is stored. Refer to HVAC System Test (MTC) for stored DTC test procedures. HVAC System Test (MTC)

Diagnostic Test

1. RUN THE ACTUATOR DTC DETECTION TEST
Turn the ignition on.
With the scan tool in HVAC, erase DTCs.
Turn the ignition off, wait 10 seconds, and then turn the ignition on.
With the scan tool, select System Tests and then select Actuator DTC Detection. When the test is complete, select View DTCs.

Repair
Diagnose and repair the DTC(s). If multiple DTCs are present, beginning with the common circuits, diagnose and repair all short high DTCs and then all short low DTCs. Refer to the Trouble Code Diagnostic Charts for a complete list of all HVAC related symptoms.