Actuator Calibration/Diagnostics and Cool-Down Test

AUTOMATIC TEMPERATURE CONTROL (ATC)

The AC Cooldown Test:
- is actuated with the DRBIII(R).
- checks A/C system performance based on evaporator temperature sensor input.

- will not run:
- if ambient temperature is below 12° C(53° F).
- if A/C pressure is below 50 psi or above 300 psi
- if the evaporator temperature sensor/circuit is open.
- if the evaporator temperature sensor/circuit is shorted.

- will pass if the evaporator temperature drops either 6.7° C(20° F) within two minutes at ambient temperatures of 21° C(70° F) or above, or if the evaporator temperature drops 9.4° C(15° F) within two minutes at ambient temperatures below 21° C(70° F).
- messages display on the DRBIII(R) after running this test.
- These messages will clear after paging back out of this test. Therefore, it is important to note all of the AC Cooldown test messages before doing so.
- will cause the DELAY VF segment and Snowflake LED on the ATC to flash. If the test fails the VF segment and LED will continue to flash until either the vehicle is driven more than three miles or a successful AC Cooldown Test is performed.

Actuator Calibration:
- occurs after turning on the ignition after a battery reconnect.
- occurs after ATC installation or replacement. - occurs after 20 ignition cycles.
- can be initiated by the DRBIII(R) by selecting Body, Automatic Temperature Control, Miscellaneous, and Reset ATC Head.
- can be initiated by pressing the PWR and RE-CIRC buttons simultaneously for five seconds.
- Manual motor calibration will cause the DELAY and RECIRC VF segments on the ATC to flash. If the test fails the VF segments will continue to flash until either the vehicle is driven more than three miles or a successful calibration occurs.

MANUAL TEMPERATURE CONTROL (MTC)

The A/C Cooldown Test:
- is actuated with the DRBIII(R).
- checks A/C system performance based on evaporator temperature sensor input.
- will not run if ambient temperature is below 12.7° C(55° F).
- will pass if the evaporator temperature drops 6.7° C(20° F) within two minutes of starting the test.
- faults display on the DRBIII(R) as test messages only after running the test.
- faults will not display on the DRBIII(R) as Diagnostic Trouble Codes.
- will cause the PWR and A/C status indicators on the A/C Heater Control to flash alternately while the test is running.
- The A/C status indicator will flash twice per second to indicate that the A/C Cooldown Test needs to be run. The A/C status indicator will stop flashing twice per second if either the A/C Cooldown Test returns passed, or if any button on the control is pressed, or if the ignition is cycled and the odometer shows greater than eight miles.

The HVAC Door Recalibration function:
- is actuated with the DRBIII(R).
- After completing HVAC Door Recalibration, the DRBIII(R) stores the total span and the status of each door actuator. Selecting HVAC Door Cal Monitor in the System Tests will display this information.

- homes and repositions door actuators.
- monitors for door span faults on the actuator circuits.
- faults display on the DRBIII(R) as test messages only after running the test.
- faults will not display on the DRBIII(R) as Diagnostic Trouble Codes.
- will cause the PWR and RECIRC status indicators on the A/C Heater Control to flash alternately while the test is running.
- The RECIRC status indicator will flash twice per second to indicate that the HVAC Door Recalibration Test needs to be run. The RECIRC status indicator will stop flashing twice per second if either the HVAC Door Recirculation Test returns passed, or if any button on the control is pressed, or if the ignition is cycled and the odometer shows greater than eight miles.