Backlight Dimming RX Failure (Active)

Test 1 - 2:

Test 3:

SYMPTOM
BACKLIGHT DIMMING RX FAILURE (ACTIVE)

WHEN MONITORED
With the ignition on.

SET CONDITION
If the A/C - Heater Control Module does not receive the dimming function message from the Instrument Cluster for more than 5 seconds, then the A/C - Heater Control Module backlighting will default to full brightness and the DTC will set.

POSSIBLE CAUSES
- Check for instrument cluster (MIC) DTCs
- Dimming message not seen at rate expected
- A/C - heater control module
- MIC - no dim message to a/c - heater control module