B260B

DTC B260B or B260C

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 B260B 01
- Left Daytime Running Lamp Relay Control Circuit Short to Battery

DTC B260B 02
- Left Daytime Running Lamp Relay Control Circuit Short to Ground

DTC B260B 04
- Left Daytime Running Lamp Relay Control Circuit Open

DTC B260C 01
- Right Daytime Running Lamp Relay Control Circuit Short to Battery

DTC B260C 02
- Right Daytime Running Lamp Relay Control Circuit Short to Ground

DTC B260C 04
- Right Daytime Running Lamp Relay Control Circuit Open

Diagnostic Fault Information





Circuit/System Description

The headlamp switch is supplied with ground at all times. When the headlamp switch is placed in either the park or low beam position, ground is applied to the tail lamp signal circuit to the body control module (BCM). The BCM responds by applying battery voltage to the left/right park lamps, left/right side marker lamps and left/right tail lamps. This energizes the appropriate lamp.

Conditions for Running the DTC

* The engine is running.
* Headlamp switch in AUTO position.
* The ambient light is day.

Conditions for Setting the DTC

B260B 01 or B260C 01

The BCM detects a short to voltage on the daytime running lamp relay control circuit.

B260B 02 or B260C 02

The BCM detects a short to ground on the daytime running lamp relay control circuit.

B260B 04 or B260C 04

The BCM detects an open/high resistance on the daytime running lamp relay control circuit.

Action Taken When the DTC Sets

B260B 01 or B260C 01

The appropriate daytime running lamp will be continuously illuminated.


B260B 02, B260C 04, B260B 02 or B260C 04

The appropriate daytime running 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)

Circuit/System Verification

Ignition ON, command the Left Dedicated Daytime Running Lamp and the Right Dedicated Daytime Running Lamp ON and OFF with a scan tool. The E4C daytime running lamp - left and the E4D daytime running lamp - right should turn ON and OFF while changing between the commanded states.

Circuit/System Testing

1. Ignition OFF, disconnect the appropriate KR42 daytime running lamp relay.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 86 and ground.

• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.

3. Connect a test lamp between the B+ circuit terminal 86 and the control circuit terminal 85.
4. Command the appropriate Front Park Lamp test 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 ground. If the circuit tests normal, replace the K9 BCM.
• If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K9 BCM.

5. If all circuits test normal, test or replace the KR42 daytime running lamp relay.

Component Testing

Relay Test
1. Ignition OFF, disconnect the appropriate KR42 daytime running lamp relay.
2. Test for 60-180 ohm between terminals 85 and 86.

• If not within the specified range, replace the KR42 daytime running lamp relay.

3. Test for infinite resistance between the following terminals:

* 30 and 86
* 30 and 87
* 30 and 85
* 85 and 87

• If not the specified value, replace the KR42 daytime running lamp relay.

4. Install a 15A fused jumper wire between relay terminal 85 and 12 V. Install a jumper wire between relay terminal 86 and ground. Test for less than 2 ohm between terminals 30 and 87.

• If greater than the specified range, replace the KR42 daytime running lamp relay.

Repair Instructions

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

* Headlamp Replacement (Headlamp Replacement)
* Relay Replacement (Attached to Wire Harness) (Relay Replacement (Attached to Wire Harness))Relay Replacement (Within an Electrical Center) (Relay Replacement (Within an Electrical Center))
* Control Module References (Programming and Relearning) for BCM replacement, setup and programming