• | 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 00 | 1 | 2 | -- |
Ground | -- | 1 | -- | -- |
|
Battery voltage is applied at all times to the body control module (BCM) from the CHMSL/BCK-UP Fuse located in the rear fuse block. When the brake pedal is applied and the BCM receives a brake applied signal from the brake pedal position sensor (BPPS). It then applies battery voltage from the CHMSL/BCK-UP fuse through the CHMSL voltage supply circuit to the CHMSL.
The ignition is ON. The stop lamps must be commanded ON.
The BCM detects a short to ground on the CHMSL voltage supply circuit when the stop lamps are being commanded ON.
The CHMSL does not illuminate.
• | The condition responsible for setting the DTC no longer exists. |
• | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. |
Lighting Systems Connector End Views
⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
⇒ | If the test lamp is always ON, test the voltage supply circuit for a short to voltage. If the circuit tests normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the voltage supply circuit for a short to ground 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 |