• | 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 |
---|---|---|---|---|
CHMSL Voltage Supply | B3445 | 1 | 2 | -- |
1. Stop Lamps Inoperative 2. Stop Lamps Always On |
Battery voltage for the center high mounted stop lamp (CHMSL) is applied from the CHMSL/DIMR 15 amp Fuse in the I/P electrical center to the body control module (BCM). When the brake pedal is applied, a signal is applied to the BCM. The BCM then applies a voltage to the CHMSL voltage supply circuit to the CHMSL.
The ignition is ON. The stop lamps must be commanded ON.
The BCM receives a ground signal on the CHMSL voltage supply circuit when the stop lamps are being commanded ON.
The CHMSL does not illuminate.
The BCM clears this code from current when the fault is removed from the system.
Lighting Systems Connector End Views
Ignition ON, press the brake pedal. The CHMSL should illuminate.
⇒ | If the test lamp illuminates, test for a short to ground in the CHMSL voltage supply circuit. If all circuits/connections test normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
• | Control Module References for BCM replacement, setup, and programming |