A/C Cool Down Test

The heater-A/C control module can perform an A/C cool down test, which is a test performed during the manufacturing process to confirm that the air conditioning system is performing satisfactorily This test can also provide a quick confirmation of air conditioning system performance to the service technician. If the test is completed satisfactorily no further service is required. If the test is failed, proceed to the A/C Performance Test to confirm the a/c system is operating properly or use a DRB III scan tool to diagnose the A/C system control and distribution systems. Refer to the appropriate diagnostic information.

Manual Temperature Control
The front blower speed and rear blower speed (if equipped with rear HVAC) must be set to High and the evaporator temperature sensor must be greater than 55 °F or the test will fail immediately. The test is activated by depressing the A/C and PWR buttons simultaneously and holding them depressed for no less than five seconds. The PWR and A/C LEDs will blink ON and OFF until the test is complete. If the LEDs stop blinking before two minutes, then the cool down test has been completed successfully If the two minutes expire without the expansion valve temperature reaching 20 °F less than the outside air temperature, then the cool down test has been failed and further A/C system diagnosis is required. If the test is failed, the LEDs will continue to blink until the vehicle has been driven for greater than (8 miles).

Automatic Temperature Control
The ambient air temperature in the room where the vehicle will be tested must be a minimum of 21 °C (70 °F) for this test. The test is activated by depressing the A/C and PWR buttons simultaneously and holding them depressed for no less than four seconds. The snowflake icon and the DELAY text in the ATC display will blink ON and OFF alternately until the test is complete. If the snowflake icon and the DELAY text stop blinking before two minutes, then the cool down test has been completed successfully If the two minutes expire without the evaporator temperature reaching 20 °F less than the evaporator initial temperature, then the cool down test has been failed and further A/C system diagnosis is required. If the test is failed, the snowflake icon and the DELAY text will continue to blink across ignition cycles until the vehicle has been driven for greater than (8 miles).