No Communication With ECM (Stored)

Test 1:

SYMPTOM
NO COMMUNICATION WITH ECM (STORED)

TEST NOTE
This symptom is diagnosed using the test A/C COMPRESSOR CONTROL HIGH OR OPEN (STORED).

WHEN MONITORED
With the ignition on.

SET CONDITION
This DTC will set if the Automatic Temperature Control (ATC) fails to receive all messages from the ECM.

POSSIBLE CAUSES
- Check for active automatic temperature control (ATC) DTC's
- Intermittent condition