B2605
DTC B2600 or B2605
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 B2600 01
- Left Daytime Running Lamps Control Circuit Short to Battery
DTC B2600 02
- Left Daytime Running Lamps Control Circuit Short to Ground
DTC B2600 04
- Left Daytime Running Lamps Control Circuit Open
DTC B2605 01
- Right Daytime Running Lamps Control Circuit Short to Battery
DTC B2605 02
- Right Daytime Running Lamps Control Circuit Short to Ground
DTC B2605 04
- Right Daytime Running Lamps Control Circuit Open
Diagnostic Fault Information
Circuit/System Description
When the headlight switch is in the Auto position and the ambient light sensor detects sunlight, the body control module (BCM) will command the daytime running lamps to illuminate by providing 12 volts to the daytime running lamp control circuit.
Conditions for Running the DTC
* The engine is running.
* Headlamp switch in AUTO position.
* The ambient light is day.
Conditions for Setting the DTC
B2600 01 or B2605 01
The BCM detects a short to voltage on the daytime running lamp control circuit
B2600 02 or B2605 04
The BCM detects a short to ground on the daytime running lamp control circuit
B2600 04 or B2605 04
The BCM detects an open/high resistance on the daytime running lamp control circuit
Action Taken When the DTC Sets
B2600 01 or B2605 01
The daytime running lamp will be continuously illuminated.
B2600 02, B2600 04, B2605 02 or B2605 04
The 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
Headlights/Daytime Running Lights (DRL) Schematics (Headlights/Daytime Running Lights (DRL) 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
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 X1 harness connector K9 BCM.
2. Ignition ON, verify that a test lamp illuminates between the B+ circuit terminal 3 and ground.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance.
3. Ignition OFF, connect the X1 harness connector K9 BCM
4. Ignition OFF, disconnect the inline harness connector listed below:
* E4C daytime running lamp - left X111 inline harness connector
* E4D daytime running lamp - right X116 inline harness connector
5. Connect a test lamp between the control circuit terminal G and ground.
6. Command the appropriate Dedicated Daytime Running 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 circuits test normal, replace the K9 BCM.
7. If all circuits test normal, replace the daytime running lamp bulb.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Daytime Running Lamp Bulb Replacement (TT6,TT7,TT8 Passenger Side Headlamp) (Daytime Running Lamp Bulb Replacement (TT6,TT7,TT8 Passenger Side Headlamp))Daytime Running Lamp Bulb Replacement (T84, T85 Passenger Side Headlamp) (Daytime Running Lamp Bulb Replacement (T84, T85 Passenger Side Headlamp))Daytime Running Lamp Bulb Replacement (T84, T85 Driver Side Headlamp) (Daytime Running Lamp Bulb Replacement (T84, T85 Driver Side Headlamp))Daytime Running Lamp Bulb Replacement (TT6,TT7,TT8 Driver Side Headlamp) (Daytime Running Lamp Bulb Replacement (TT6,TT7,TT8 Driver Side Headlamp))
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming