• | 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 |
---|---|---|---|---|
Parklamp Control Circuit | B2585 00 B3867 00 | B2585 00 B3867 00 | B2585 00 B3867 00 | -- |
Headlamp Switch Parklamp Signal Circuit | 1 | 2 | -- | -- |
Headlamp Switch Parklamp Ground Circuit | -- | 2 | 2 | -- |
Headlamp Switch | 1 | 2 | 2 | -- |
1. Parklamp Always ON 2. Parklamp Inoperative |
The body control module (BCM) controls the park lamp relay by grounding the control circuit on the park lamp relay when the headlamp switch is turned to the PARK or the HEAD position. This energizes the park lamp relay, illuminating the park lamps.
A short to ground, a short to voltage or an open in the following location may cause a malfunction to occur:
• | The park lamp relay control circuit |
• | The park lamp relay |
• | The headlamp switch supply circuit |
• | The headlamp switch ground circuit |
• | The headlamp switch |
• | The BCM |
Ignition ON, turn the headlamps ON with the headlamp switch. Observes the park lamps, the park lamps should be ON.
⇒ | If not OFF, test the signal circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If not ON, test the signal circuit of the headlamp switch for a short to voltage or an open/high resistance. If circuit tests normal, replace the BCM. |
⇒ | If less than infinite resistance, replace the headlamp switch. |
⇒ | If greater than 1.5 ohms, replace the headlamp switch. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |