• | 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 |
---|---|---|---|---|
Headlamp Switch High Beam Signal | 2 | 2 | 2 | -- |
Headlamp Switch Headlamps ON Signal | 3 | 3 | 3 | -- |
Headlamp Switch Headlamps OFF Signal | 3 | 3 | 3 | -- |
Headlamp High Beam Relay Control | B2582 00 | 2 | 2583 00 | -- |
Headlamp Low Beam Relay Control | 1 | 1 | B2575 00 | -- |
LF High Beam Headlamp Control | 2 | 2 | 2 | -- |
LF Low Beam Headlamp Control | 1 | 1 | 1 | -- |
RF High Beam Headlamp Control | 2 | 2 | 2 | -- |
RF Low Beam Headlamp Control | 1 | 1 | 1 | -- |
LF Headlamp Ground | -- | 1 | -- | -- |
RF Headlamp Ground | -- | 1 | -- | -- |
Turn Signal/Multifunction Switch Ground | -- | 4 | -- | -- |
1. Headlamp Malfunction - Low Beam 2. Headlamp Malfunction - High Beam 3. Headlamp Switch Malfunction 4. Dimmer Switch Malfunction |
When the body control module (BCM) receives a ground signal from the multifunction high beam or flash to pass (FTP) switch commanding to illuminate the high beam headlamps, the BCM will energize the HI/LO BEAM relay by applying B+ to the HI/LO BEAM relay control circuit.
Battery voltage must be between 9-16 volts.
When the BCM receives a high beam switch on command and the front fog lamp relay control circuit is shorted to ground.
When the BCM receives a high beam switch off command and the front fog lamp relay control circuit is shorted to voltage.
The high beam headlamps will not operate or will remain always on.
• | This DTC will clear on current status after the condition for setting the fault is corrected. |
• | A history DTC will clear after 100 consecutive ignition cycles without a fault present. |
Headlights/Daytime Running Lights (DRL) Schematics
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
⇒ | If less than the specified value, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the control circuit for a short to ground 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. |