B3881

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 01
- Left Tail Lamp Circuit Short to Battery

DTC B3881 02
- Left Tail Lamp Circuit Short to Ground

DTC B3881 04
- Left Tail Lamp Circuit Open

DTC B3882 01
- Right Tail Lamp Circuit Short to Battery

DTC B3882 02
- Right Tail Lamp Circuit Short to Ground

DTC B3882 04
- Right Tail Lamp Circuit Open

Diagnostic Fault Information






Circuit/System Description

When the turn signal/multifunction switch is placed in the HEAD or PARK position, ground is applied to the park lamp switch ON signal circuit to the body control module (BCM). The BCM responds by applying voltage to the park lamps and license lamps control circuits illuminating the park and license lamps.

Conditions for Running the DTC

* Battery voltage must be between 9-16 V.
* Park lamps ON.

Conditions for Setting the DTC

DTC B3881 01 and B3881 04

The BCM detects a short to voltage or an open/high resistance in the left rear park lamp control circuit.

DTC B3881 02

The BCM detects a short to ground in the left rear park lamp control circuit.

DTC B3882 01 and B3882 04

The BCM detects a short to voltage or an open/high resistance in the right rear park lamp control circuit.

DTC B3882 02

The BCM detects a short to ground in the right rear park lamp control circuit.

Actions Taken When the DTC Sets

DTC B3881 01

The left rear park lamp is always ON.

DTC B3881 02 and B3881 04

The left rear park lamp is inoperative.

DTC B3882 01

The right rear park lamp is always ON.

DTC B3882 02 and B3882 04

The right rear park lamp is inoperative.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 100 consecutive malfunction-free vehicle ON/OFF switch cycles have occurred.

Reference Information
Schematic Reference

Exterior Lights Schematics Exterior Lights Schematics
Connector End View Reference

Component Connector End Views Hybrid/EV Battery Pack X1
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 Testing

1. Vehicle OFF, disconnect the harness connector at the appropriate E42 tail lamp assembly.
2. Vehicle OFF, exterior lamps OFF, test for less than 5 ohm between the ground circuit terminal 4 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 2 and ground.
4. Vehicle in Service Mode, command the appropriate Rear Park 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, replace the E42 tail lamp assembly.

Repair Instructions

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

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