Reset Procedure

HVAC System Test
The HVAC System Test, provides a starting point in the diagnostic process by identifying the appropriate diagnostic procedure or system test to perform when diagnosing a given symptom, condition, or DTC. It also provides a means for testing the entire HVAC system by utilizing the A/C-heater control's On-Board System Tests. The On-Board System Tests can also assist in diagnosing stored DTCs.

A/C COOLDOWN TEST
The A/C Cooldown Test:
- is actuated with a scan tool.
- tests A/C system performance based on evaporator temperature sensor input.
- will fail if evaporator temperature is below 18.3° C (65° F) when initiating the test.
- will pass if the evaporator temperature drops 11.1° C (20° F).
- indicates an outcome by displaying one or more test status messages on the scan tool. These test status messages will clear after paging back out of this test function. Therefore, is it important to note all of the messages before doing so.
- will cause the A/C status indicator to flash while the test is running.

ACTUATOR CALIBRATION FUNCTION
The Actuator Calibration function:
- is actuated with a scan tool.
- homes and repositions door actuators.
- monitors for door span faults. Door span faults (XXX Door Travel Range Too Large or XXX Door Travel Range Too Small) will only display after calibration.
- will cause the electric backlight (EBL) status indicator (if equipped) to flash while the test is running.

ACTUATOR DTC DETECTION TEST
The Actuator DTC Detection Test:
- is actuated with a scan tool.
- supplements the continuous diagnostics on the actuator drive system.
- monitors for shorted actuator circuits allowing service to easily diagnose and troubleshoot up to three simultaneous shorts. Shorted actuator circuit faults (XXX Control Circuit High or XXX Control Circuit Low) will only display after running the Actuator DTC Detection Test.

After repairing each DTC, cycle the ignition switch, and then run the Actuator DTC Detection Test again to ensure that no new DTCs exist. If multiple DTCs are present, beginning with the common circuit, diagnose and repair all short high faults and then short low faults. When the test returns passed, clear all faults and run the Actuator Calibration function as a final check of system health.