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 Descriptors
DTC B3884 01: Center High Mounted Brake Lamp Circuit Short to BatteryDTC B3884 02: Center High Mounted Brake Lamp Circuit Short to Ground
DTC B3884 04: Center High Mounted Brake Lamp Circuit Open
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
Center High Mounted Brake Lamp | B3884 02 | B3884 04 | B3884 01 | -- |
Circuit/System Description
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 to the body control module (BCM). The BCM will apply battery voltage to the right, left and center stop lamp control circuits and to the trailer lighting converter if installed in the vehicle.
Conditions for Running the DTC
B3884 01
Brakes are not applied.
B3884 02 or B3884 04
Brakes are applied.
Conditions for Setting the DTC
B3884 01
The BCM detects a short to voltage on the control circuit.
B3884 02
The BCM detects a short to ground on the control circuit.
B3884 04
The BCM detects an open control circuit.
Conditions for Clearing the DTC
The condition for setting the DTC is no longer present.
Reference Information
Schematic Reference
Connector End View Reference
Description and Operation
Electrical Information Reference
Scan Tool Reference
Control Module References for scan tool information
Circuit/System Verification
Ignition ON, perform the Center Brake Lamp Command test. The center brake lamp should be ON / OFF.
Circuit/System Testing
- Ignition OFF, disconnect the harness connector at the E6 Center High Mounted Stop Lamp (CHMSL).
- Test for less than 5 Ω between the E6 Center High Mounted Stop Lamp (CHMSL) ground circuit harness connector terminal 1 and ground.
- Connect a test lamp between the E6 Center High Mounted Stop Lamp (CHMSL) control circuit harness connector terminal 2 and ground.
- Command the Center Brake Lamp Command test with a scan tool. The test lamp should turn ON and OFF when changing between the commanded states.
- If all circuits test normal, replace the E6 Center High Mounted Stop Lamp (CHMSL).
| ⇒ | If greater than the specified value, test the ground circuit for an open / high resistance. |
| ⇒ | If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 Body Control Module (BCM). |
| ⇒ | If the test lamp is always OFF, test the control circuit for a short to ground or an open / high resistance. If the circuit tests normal, replace the K9 Body Control Module (BCM). |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for BCM replacement, setup and programming |
