Diagnostic Instructions
| • | 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. |
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Park Lamp Voltage Supply | 4 | 4 | 3 | -- |
Park Lamp Relay Control | 3 | 4 | 4 | -- |
Park Lamp Switch Signal | 3 | 4 | 4 | -- |
License Lamp Supply Voltage | 1 | 1 | 3 | -- |
Marker Lamp Voltage Supply | 2 | 2 | 3 | -- |
License Lamp Ground | -- | 1 | 4 | -- |
Marker Lamp Ground | -- | 2 | 4 | -- |
Park/Turn Signal/DRL Lamps - LF Ground | -- | 4 | 4 | -- |
Park/Turn Signal/DRL Lamps - RF Ground | -- | 4 | 4 | -- |
Tail/Stop and Turn Signal Lamps - LR Ground | -- | 4 | 4 | -- |
Tail/Stop and Turn Signal Lamps - RR Ground | -- | 4 | 4 | -- |
Turn Signal/Multifunction Switch Ground | -- | 4 | 4 | -- |
1. License Lamps Inoperative 2. Marker Lamps Inoperative 3. Park Lamps Always On 4. Park Lamps Inoperative | ||||
Circuit/System Description
Battery voltage is applied at all times to the coil and switch sides of the PARK LAMP Relay located in the underhood fuse block. Ground is applied at G201 to the turn signal/multifunction switch at all times. When the headlamp switch is placed in either the HEAD or PARK position, ground is applied to the park lamp switch signal circuit to the body control module (BCM). The BCM reacts to the signal from the park lamp switch by applying ground to the park lamp relay control circuit. This energizes the PARK LAMP Relay and applies battery voltage to the PARK LPS fuse. Voltage flows through the PARK LPS fuse to all park, tail, license, and side marker lamps. Ground for the front park and side marker lamps is supplied at G101 for the left and G102 for the right. Ground for the license and right rear tail lamps is supplied at G402, and the left rear tail lamps at G400.
Reference Information
Schematic Reference
Connector End View Reference
Lighting Systems Connector End Views
Electrical Information Reference
Scan Tool Reference
Circuit/System Testing
- Ignition OFF , disconnect the park lamp relay.
- Ignition ON, the park lamps should turn OFF.
- Connect a test lamp between the park lamp relay control circuit and the park lamp relay coil side supply voltage circuit at the underhood fuse block relay terminals.
- Ignition ON, turn the park lamps ON and OFF. The test lamp should turn ON and OFF as the switch is cycled.
- Connect the park lamp relay.
- Ignition OFF, disconnect the BCM C1 harness connector.
- Ignition ON, the park lamps should turn OFF.
- Ignition OFF, connect the BCM C1 harness connector.
- Disconnect the C1 harness connector at the turn signal/multifunction switch.
- Ignition ON, the park lamps should turn OFF.
- If all circuits test normal, replace the turn signal/multifunction switch.
| ⇒ | If the park lamps remain illuminated, repair the park lamps voltage supply circuit for a short to voltage. If the circuit tests normal, replace the underhood fuse block. |
| ⇒ | If the test lamp turns ON and OFF as the turn signal/multifunction switch is cycled, replace the park lamp relay. |
| ⇒ | If the park lamps remain illuminated, repair the park lamp relay control circuit for a short to ground. |
| ⇒ | If the park lamps remain illuminated, repair the park lamp switch signal circuit for a short to ground. If the circuit tests normal, replace the BCM. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
