Loopback Test Failure (Stored)

Test 1:

SYMPTOM
LOOPBACK TEST FAILURE (STORED)

TEST NOTE
This symptom is diagnosed using the test A/C SWITCH FAULT (STORED).

WHEN MONITORED
When the A/C - Heater Control Module executes an internal loopback test.

SET CONDITION
If the A/C - Heater Control Module fails to send a message, or none of the expected messages arrive for 5 seconds, an internal loopback test is executed. If the internal loopback test fails, the DTC will set.

POSSIBLE CAUSES
- Check for active HVAC DTCs and system test fault messages
- stored code(s) test complete