HVAC, ATC

B10B2-A/C COOL DOWN TEST PERFORMANCE

For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The A/C Heater Controller has software to enable it to perform an A/C Cool Down Test by a command using a scan tool. This test checks for evaporator temperature drop over a predetermined time. If the test fails, this DTC will set. However, certain test conditions are required to perform this test. Failure to run this test within those parameters can result in failure of the test.

- When Monitored:
With ever an A/C Cooldown Test is performed.

- Set Condition:
This DTC is set whenever the A/C Cooldown Test is performed and the desired temperature drop is not achieved by the system. The DTC will go to stored after a successful A/C Cooldown Test.





Always perform the HVAC Pre-Diagnostic Troubleshooting procedure before proceeding. Initial Inspection and Diagnostic Overview.
CONDITIONS FOR A/C COOLDOWN TEST
1. The following condition must be met before running the A/C Cooldown test.
- No Powertrain Control Module (PCM) DTCs present
- Condenser cooling fan working properly
- No active HVAC evaporator temperature sensor, sun sensor, recirculation, mode, or blend door actuator DTCs present
- The refrigerant system must be fully charged
- The blower motor must operate correctly in all speeds
- The evaporator temperature must be above 12.7° C (55° F)
- The A/C compressor must be turned off
- Blower must be on high

Are all of the above conditions met before running the A/C Cooldown Test?

Yes

- Refer to the additional Cooldown Test related diagnostic information and testing procedures and repair as necessary.

NOTE: Run the Cooldown Test again after any repairs are performed.

- If the Cooldown Test passes, perform HVAC VERIFICATION TEST HVAC Verification Test.

No

- Run the A/C Cooldown test again with the above test conditions.