B2600
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 Descriptors
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
The ambient light sensor is used to monitor outside lighting conditions. The body control module (BCM) provides a 5-volt reference signal to the ambient light sensor. Depending on outside lighting conditions, the ambient light sensor provides a voltage signal to the BCM that will vary between 0.2 and 4.9 volts. The BCM monitors the ambient light sensor signal circuit to determine if outside lighting conditions are correct for either daytime running lights (DRL) or automatic headlamp system control when the headlamp switch is in the AUTO position. In daylight conditions, the BCM will command the low beam headlamps (DRLs) ON by applying low voltage to the low beam headlamp control circuits illuminating the low beam headlamps at reduced intensity. Any function or condition that turns on the headlamps will cancel DRL operation.
Conditions for Running the DTC
* Battery voltage must be between 9-16 V.
* Headlamp switch in AUTO position.
Conditions for Setting the DTC
DTC B2600 01
The BCM detects a short to voltage in the left DRL control circuit.
DTC B2600 02
The BCM detects a short to ground in the left DRL control circuit.
DTC B2600 04
The BCM detects an open/high resistance in the left DRL control circuit.
DTC B2605 01
The BCM detects a short to voltage in the right DRL control circuit.
DTC B2605 02
The BCM detects a short to ground in the right DRL control circuit.
DTC B2605 04
The BCM detects an open/high resistance in the right DRL control circuit.
Actions Taken When the DTC Sets
* When DTC B2600 sets, the left DRL will be inoperative.
* When DTC B2605 sets, the right DRL will be 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
Headlights/Daytime Running Lights (DRL) Schematics Headlights/Daytime Running Lights (DRL) Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly - Primary
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 E4 daytime running lamp.
2. Test for less than 5 ohms between the ground circuit terminal 2 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 1 and ground, ignition ON.
4. Verify the test lamp turns ON and OFF when commanding the Dedicated Daytime Running Lamp Command 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 E4 daytime running lamp.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Daytime Running Lamp Replacement (RS) Daytime Running Lamp Replacement (RS)Daytime Running Lamp Replacement (ZL1) Daytime Running Lamp Replacement (ZL1)
* Daytime Running Lamp Bulb Replacement (RS) Daytime Running Lamp Bulb Replacement (RS)Daytime Running Lamp Bulb Replacement (SS) Daytime Running Lamp Bulb Replacement (SS)Daytime Running Lamp Bulb Replacement (ZL1) Daytime Running Lamp Bulb Replacement (ZL1)
* Control Module References Control Module References for BCM replacement, programming, and setup