• | 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 |
---|---|---|---|---|
Body Control Module (BCM) B+ Terminal 1 X4 | 1 | 1 | -- | -- |
Body Control Module (BCM) B+ Terminal 3 X4 | 2 | 2 | -- | -- |
Brake Pedal Position Sensor 5-Volt Reference | C0277 06, C0890 03 | C0277 06 | C0277 06 | -- |
Brake Applied Signal | C0297 00 | 4 | 4 | -- |
Brake Pedal Position Sensor Signal | C0277 06 | C0277 06 | C0277 07 | C0277 09, C0277 4B |
Center High Mounted Stop Lamp (CHMSL) Control | B3445 00, B3884 00 | 3 | 3 | -- |
Left Rear Stop/Turn Lamp Control | 1 | 1 | 1 | -- |
Right Rear Stop/Turn Lamp Control | 2 | 2 | 2 | -- |
Brake Pedal Position Sensor Low Reference | -- | C0277 06 | 1 | -- |
Center High Mounted Stop Lamp (CHMSL) Ground | -- | 3 | -- | -- |
Left Rear Stop/Turn Lamp Ground | -- | 1 | -- | -- |
Right Rear Stop/Turn Lamp Ground | -- | 2 | -- | -- |
1. Stop Lamps Malfunction - Left 2. Stop Lamps Malfunction - Right 3. Center High Mounted Stop Lamp (CHMSL) Malfunction 4. Cruise Control Malfunction |
The brake pedal position sensor is used to sense the action of the driver application of the brake pedal. The brake pedal position sensor provides an analog voltage signal that will increase as the brake pedal is applied. The body control module (BCM) provides a low reference signal and a 5-volt reference voltage to the brake pedal position sensor. When the variable signal reaches a voltage threshold indicating the brakes have been applied, the BCM will apply battery ltage to the stop lamps, center high mounted stop lamp (CHMSL), transmission control module (TCM), and engine control module (ECM).
• | Battery voltage must be between 9-16 volts. |
• | Brakes APPLIED. |
The BCM detects a short to ground in the brake applied signal circuit.
• | The BCM stores the DTC to memory. |
• | The Service Vehicle Soon indicator is commanded ON. |
• | The condition responsible for setting the DTC no longer exists. |
• | A history DTC will clear once 50 malfunction-free ignition cycles have occurred. |
Exterior Lighting Systems Description and Operation
Control Module References for scan tool information
• | Brake applied signal terminal 7 - with LS4 |
• | Brake applied signal terminal 9 - with LZE, LZ4, or LZ8 |
⇒ | If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit test normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the BCM. |
• | Brake applied signal terminal 7 - with LS4 |
• | Brake applied signal terminal 9 - with LZE, LZ4, or LZ8 |
⇒ | If the test lamp does not turn ON and OFF when commanded, replace the ECM. |
⇒ | If the test lamp is always ON, test the signal circuit for a short to voltage. If the circuit test normal, replace the BCM. |
⇒ | If the test lamp is always OFF, test the signal circuit for a short to ground or an open/high resistance. If the circuit test normal, replace the BCM. |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for BCM, ECM or TCM replacement, setup and programming