B3882

DTC B3881 or B3882

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Diagnostic System Check - Vehicle) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Strategy Based Diagnosis) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Diagnostic Procedure Instructions) provides an overview of each diagnostic category.

DTC Descriptors
DTC B3881 02
- Tail Lamp Circuit Short to Ground

DTC B3881 04
- Tail Lamp Circuit Open

DTC B3882 02
- Right Tail Lamp Circuit Short to Ground

DTC B3882 04
- Right Tail Lamp Circuit Open

Diagnostic Fault Information





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.

Conditions for Running the DTC

Brake pedal is applied.

Conditions for Setting the DTC

B3881 01

The BCM detects a short to voltage on the left rear brake lamp control circuit.

B3881 02

The BCM detects a short to ground on the left rear brake lamp control circuit.

B3882 01

The BCM detects a short to voltage on the right rear brake lamp control circuit.

B3882 02

The BCM detects a short to ground on the right rear brake lamp control circuit.

Action Taken When the DTC Sets

The appropriate brake lamp will be inoperative.

Conditions for Clearing the DTC

* The DTC will be current for as long as the fault is present.
* When the fault is no longer present, the DTC will be a history DTC.
* A history DTC will clear after 50 ignition cycles.

Reference Information
Schematic Reference

Exterior Lights Schematics (Exterior Lights Schematics)
Connector End View Reference

Component Connector End Views (Connector End Views By Name)
Description and Operation

Exterior Lighting Systems Description and Operation (Exterior Lighting Systems)
Electrical Information Reference

* Circuit Testing (Circuit Testing)
* Connector Repairs (Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (Wiring Repairs)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Verification

1. Ignition ON, observe the function of the E5L stop lamp-left while commanding the Left Brake Lamp ON and OFF with a scan tool. The E5L stop lamp-left should turn ON and OFF while changing between the commanded states
2. Observe the function of the E5R stop lamp-right while commanding the Right Brake Lamp ON and OFF with a scan tool. The E5R stop lamp-right should turn ON and OFF while changing between the commanded states.

Circuit/System Testing

1. Ignition OFF, disconnect the X1 harness connector at the appropriate E5 tail lamp.
2. Test for less than 30 ohm between the ground circuit terminal C and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance

3. Connect a test lamp between the control circuit terminal A and ground
4. Ignition ON, command the Brake Lamp ON and OFF with a scan tool, the test lamp should turn ON and OFF when changing between the commanded states.

• If the test lamp is always ON, test the control circuit for a short to voltage. If the circuit tests normal, replace the K9 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 BCM.

5. If all circuits test normal, test or replace the E5 tail lamp.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Tail Lamp Replacement (Service and Repair)
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming