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 ignition cycles have occurred.
Reference Information
Schematic Reference
Exterior Lights Schematics Exterior Lights Schematics
Connector End View Reference
Component Connector End Views Outside Rearview Mirror - Driver
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 Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF, exterior lamps OFF, disconnect the harness connector at the appropriate E42 tail lamp assembly
2. Test for less than 5 ohms between the ground circuit terminal A and ground.
• If 5 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 5 ohms
3. Connect a test lamp between the control circuit terminal C and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the appropriate Rear Park lamp ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance
3. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K9 body control module.
• If the test lamp is always ON
1. Ignition OFF, disconnect the X4 harness connector at the K9 body control module, ignition ON.
2. Test for less than 1 V between the control circuit terminal and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V, replace the K9 body control module.
• If the test lamp turns ON and OFF
5. Test or replace the appropriate tail/side marker lamp.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Tail Lamp Bulb Replacement Service and Repair
* Control Module References Control Module References for BCM replacement, programming, and setup