VF Dimming Messages Missing (Active)

Test 1:

SYMPTOM
VF DIMMING MESSAGE MISSING (ACTIVE)

WHEN MONITORED
Every 8 seconds with the ignition ON.

SET CONDITION
This DTC is set if the ATC does not receive the VF dimming message within 8 seconds.

POSSIBLE CAUSES
- ATC - VF dimming message missing
- Body control module