• | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. |
• | Review Strategy Based Diagnosis for an overview of the diagnostic approach. |
• | Diagnostic Procedure Instructions provides an overview of each diagnostic category. |
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
---|---|---|---|---|
LED Dimming Control | B0951 | B0951 | 1 | -- |
Headlamp On Indicator Control | 1 | 1 | 1 | -- |
Headlamp ON Indicator Low Reference | 1 | 1 | 1 | -- |
Headlamp Switch Ground | -- | 1 | -- | -- |
1. Headlamp Switch Malfunction |
The headlamp switch indicators are supplied by the LED dimming control circuit from the BCM. The indicators are controlled on and off by the BCM through low side drive control circuits. When a headlamp switch function is activated that requires an indicator to be illuminated, the BCM will ground the control circuit and the indicator will be illuminated at the level of brightness determined by the LED dimming control.
Headlights/Daytime Running Lights (DRL) Schematics
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
Ignition ON, with the IP dimmer switch at the full bright position, operate the headlamp switch to the headlamps ON position, and back to the automatic headlamps OFF position. The headlamp switch indicators should turn ON and OFF when changing between the commanded states.
⇒ | If the test lamp does not illuminate, test the LED dimming control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the headlamp ON indicator control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, programming, and setup |