B263A

DTC B263A

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 Descriptor
DTC B263A 02
- Exterior Illumination Lamp Circuit Short to Ground

DTC B263A 04
- Exterior Illumination Lamp Circuit Open

Diagnostic Fault Information






Circuit/System Description

The exterior courtesy lamps are located in the outside rearview mirrors. When the keyless entry control module receives a request from the keyless entry transmitter to unlock the doors, the keyless entry control module will send a serial data message to the BCM, the BCM will then command the left and right door courtesy lamps to illuminate.

Conditions for Running the DTC

When the BCM will commands the left and right door courtesy lamps to illuminate.

Conditions for Setting the DTC

B263A 02

The BCM detects a short to ground on the outside rear view mirror puddle lamp control circuit.

B263A 04

The BCM detects an open/high resistance on the outside rear view mirror puddle lamp control circuit.

Action Taken When the DTC Sets

The outside mirror courtesy lamps 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 Control Module References for scan tool information

Circuit/System Verification

Ignition ON, command the Outside Rear View Mirror Courtesy Lamp ON and OFF with a scan tool. The left and right door courtesy lamps should turn ON and OFF when changing between the selected states.

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the A9A outside rearview mirror-driver and the A9B outside rearview mirror-passenger.
2. Test for less than 30 ohm between the ground circuit terminal 4 and ground.

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

3. Connect a test lamp between the control circuit terminal 17 and ground.
4. Command the Outside Rear View Mirror Courtesy 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. Ignition OFF, connect the harness connector at the A9A outside rearview mirror-driver.
6. Ignition ON, observe the function of the left door courtesy lamp while commanding the Outside Rear View Mirror Courtesy Lamp ON and OFF with a scan tool. The left door courtesy lamp should turn ON and OFF while changing between the commanded states.

• If the left door courtesy lamp is always OFF, replace the A9A outside rearview mirror-driver.

7. If all circuits test normal, test or replace the A9B outside rearview mirror-passenger.

Repair Instructions

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

* Outside Rearview Mirror Replacement Outside Rearview Mirror Replacement
* Control Module References Control Module References for BCM replacement, setup and programming