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. |
DTC Descriptor
DTC B3884 00: Stoplamp CircuitDiagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Stop Lamp Relay Coil Control | B3884 00 | 1 | 1 | -- |
1. Auxiliary Stop Lamps Malfunction | ||||
Circuit/System Description
Battery voltage is applied at all times to the body control module (BCM) from the BCM 5 Fuse located in the underhood fuse block. When the brake pedal is applied, battery voltage is applied through the stop lamp switch and the stop lamp signal circuit to the BCM. The BCM then applies battery voltage through the stop lamp relay coil supply voltage circuit energizing the STOP LAMPS PCB Relay. With the relay energized, battery voltage is applied through the switch side of the relay and the control circuit to the auxiliary stop lamps.
Conditions for Running the DTC
| • | Ignition ON. |
| • | Brakes applied. |
Conditions for Setting the DTC
The BCM detects a short to ground in the stop lamp relay coil supply voltage circuit when the stop lamps are commanded ON.
Action Taken When the DTC Sets
The BCM will deactivate power to the auxiliary stop lamps.
Conditions for Clearing the DTC
| • | The condition responsible for setting the DTC no longer exists. |
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Exterior Lighting Systems Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, press the brake pedal. The CHMSL should illuminate.
Circuit/System Testing
- Ignition OFF, disconnect the X5 harness connector at the BCM.
- Ignition ON, verify that a test lamp does not illuminate between the control circuit terminal 5 and ground.
- Ignition ON, connect a 3A fused jumper wire between the control circuit terminal 5 and B+. Verify the auxiliary stop lamps illuminate.
- If all circuits test normal, replace the BCM.
| ⇒ | If the test lamp illuminates, test the control circuit for a short to voltage. |
| ⇒ | If the stop lamps do not illuminate, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the underhood fuse block. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup, and programming |
