Daytime Running Lamps Malfunction
Daytime Running Lamps Malfunction
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.
Diagnostic Fault Information
Circuit/System Description
The body control module (BCM) receives a signal from the ambient light/sunload sensor indicating a low or high ambient outside light level. Under daylight conditions the daytime running lamps are being supplied by battery voltage. The now closed relay supplies voltage to the day time running lamps. If the headlamps are illuminated the daytime running lamps (DRL) will not illuminate.
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
1. Ignition ON, Headlamps OFF, command the Low Beams Relay Command ON and OFF with a scan tool. The low beam headlamps should turn ON and OFF when changing between the commanded states.
• If the low beam headlamps do not change between the commanded states, refer to Headlamps Malfunction (Headlamps Malfunction).
2. Observe the scan tool Ambient Light Status parameter while supplying sufficient light to simulate daylight conditions to the ambient light sensor. After 30 seconds, the parameter should be Daylight.
• If not the specified value, refer to Circuit/System Testing.
Circuit/System Testing
1. Ignition OFF, disconnect the harness connector at the B10B ambient light/sunload sensor.
2. Ignition OFF, test for less than 5 ohm between the ground circuit terminal 6 and B+.
• If greater than the specific range, test the ground circuit for an open/high resistance.
3. Ignition ON, verify the scan tool Ambient Light Sensor parameter is greater than 4.65 V.
• If less than the specified range, test the signal circuit terminal 5 for a short to ground. If the circuit tests normal, replace the K9 BCM.
4. Install a 3 A fused jumper wire between the signal circuit terminal 5 and the ground circuit terminal 6. Verify the scan tool Ambient Light Sensor parameter is less than 0.196 V.
• If greater than the specified range, test the signal circuit for a short to voltage an open/high resistance. If the circuit tests normal, replace the K9 BCM.
5. If all circuits test normal, replace the B10B ambient light/sunload sensor.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.
* Headlamp Automatic Control Ambient Light Sensor Replacement (Service and Repair)
* Headlamp Replacement (Equinox) (Removal and Replacement)Headlamp Replacement (Terrain) (Removal and Replacement)
* Control Module References (Programming and Relearning) for BCM replacement, setup, and programming