• | 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 |
---|---|---|---|---|
Park Lamps ON Signal | B257A 00 | B257A 00 | B257A 00 | -- |
Park Lamp Relay Control | 1 | 1 | B2585 00 | -- |
License Lamp Control | 1 | 1 | 1 | -- |
Park Lamp Control | 1 | 1 | 1 | -- |
License Lamp Ground | -- | 1 | -- | -- |
Park Lamps - LF Ground | -- | 1 | -- | -- |
Park Lamps - RF Ground | -- | 1 | -- | -- |
Tail/Stop and Turn Signal Lamps - LR Ground | -- | 1 | -- | -- |
Tail/Stop and Turn Signal Lamps - RR Ground | -- | 1 | -- | -- |
Headlamp Switch Ground | -- | 1 | -- | -- |
1. Park, License, and/or Tail Lamps Malfunction |
Battery positive voltage is applied at all times to both the coil and switched sides of the PARK LP Relay. When the headlamp switch is placed in either the HEAD or PARK position, ground is applied to the park lamp signal circuit to the body control module (BCM). The BCM responds by applying ground to the park lamp relay control circuit. This energizes the park lamp relay coil causing the relay switch contacts to close allowing battery voltage to flow through the LT PARK and RT PARK fuses to all of the park, tail, license, and marker lamps.
• | Battery voltage must be between 9-16 volts. |
• | Park lamps ON. |
The BCM detect a short to voltage in the park lamp relay control circuit.
The park lamps will not operate.
• | The condition responsible for setting the DTC no longer exists. |
• | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
⇒ | If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the 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, setup, and programming |