Daytime Running Lamps Malfunction
Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. Diagnostic Fault Information
| Circuit | Circuit Function | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performan |
|---|---|---|---|---|---|
| 278 | Signal | B108E 00 | B108E 00 | B108E 00 | 2 |
| 7538 | Control | B19A3 11 | 1 | 1 | — |
| 7539 | Control | B19A4 11 | 1 | 1 | — |
| 407 | Low Reference | — | B108E 00 | — | — |
| 150 | Ground | — | 1 | — | — |
| 250 | Ground | — | 1 | — | — |
| 1. Daytime running lamp malfunction 2. Ambient light sensor malfunction |
Scan Tool Functions K9 Body Control Module – Data Display – Front Exterior Lighting Data
| Data Parameter | Description |
|---|---|
| Ambient Light Intensity | This data parameter will show the status of the Ambient Light Sensor as a high LX value under bright ambient light conditions and a low LX value under dark ambient light conditions. |
K219 Lighting Control Module – Control Functions – Exterior Lighting
| Control Function | Description | ||
|---|---|---|---|
| Left Daytime Running Lamps | This control function will control the left daytime running lamp on/off | ||
| Right Daytime Running Lamps | This control function will control the right daytime running lamp on/off |
i i / i i Circuit/System Description The B10D Sun Load and Ambient Light and Security Indicator Sensor is used to monitor outside lighting conditions. The ambient light sensor provides a voltage signal that will vary between 0.2 and 4.9 V depending on outside lighting conditions. The K9 Body Control Module (BCM) provides signal circuit 278 and low reference circuit 407 to the ambient light sensor. The BCM monitors the ambient light sensor signal circuit to determine if outside lighting conditions are correct for either daytime running lamps (DRL) or automatic lamp control when the headlamp switch is in the AUTO position. In daylight conditions, the BCM will send a serial data message to the K219 Lighting Control Module to command the DRLs on. The Lighting Control Module responds by applying pulse width modulated (PWM) voltage to both DRL control circuits, illuminating the DRLs. During low light conditions, the BCM will send a serial data message to the Lighting Control Module to command the low beam headlamps ON. Diagnostic Aids Daytime running lamps (DRL) have different intensities based on ambient light conditions. The DRLs will be fully illuminated under bright ambient light conditions and have less intensity under dark ambient light conditions. Reference Information Schematic Reference Headlights/Daytime Running Lights (DRL) Schematics Connector End View Reference Master Electrical Component List Description and Operation Exterior Lighting Systems Description and Operation Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References for scan tool information Circuit/System Verification
- Ignition on/vehicle in service mode.
- Verify the Ambient Light Intensity data parameter value changes appropriately: LX value increases with an incandescent light shined on the B10D Sun Load and Ambient Light and Security Indicator Sensor to simulate bright conditions. LX value decreases with a towel covering the B10D Sun Load and Ambient Light and Security Indicator Sensor to simulate dark conditions. ⇒ If the value does not change Refer to Circuit/System Testing – Ambient Light Sensor Malfunction ⇓ If the value changes
- Verify the left and right daytime running lamps turn ON and OFF when commanding the appropriate Daytime Running Lamp ON and OFF with a scan tool. ⇒ If a daytime running lamp does not turn ON and OFF Refer to Circuit/System Testing – Daytime Running Lamps Malfunction. ⇓ If a daytime running lamp turns ON and OFF
- A fault is not currently present and may be an intermittent condition. Circuit/System Testing Ambient Light Sensor Malfunction
- Ignition OFF, disconnect the connector at the B10D Sun Load and Ambient Light and Security Indicator Sensor, ignition on.
- Verify a test lamp illuminates between low reference terminal 6 and B+. ⇒ If the test lamp does not illuminate 2.1. Test circuit 407 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 2.2. Replace the K9 Body Control Module. ⇓ If the test lamp illuminates
- Test for 4.8 V – 5.2 V between signal circuit terminal 3 and ground. ⇒ If less than 4.8 V 3.1. Test circuit 278 for a short to ground. ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found. 3.2. Test circuit 278 for an open/high resistance. ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found. 3.3. Replace the K9 Body Control Module. ⇓ If greater than 5.2 V 3.1. Test circuit 278 for a short to voltage. ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 3.2. Replace the K9 Body Control Module. ⇓ If between 4.8 V – 5.2 V
- Replace the B10D Sun Load and Ambient Light and Security Indicator Sensor.
- Ignition OFF, disconnect the connector at the appropriate component: E13LA Front Headlamp – Left = X110 E13RA Front Headlamp – Right = X120
- Verify a test lamp illuminates between ground circuit terminal 1 and B+. ⇒ If the test lamp does not illuminate 2.1. Repair the open/high resistance on the ground circuit or ground connection. ⇓ If the test lamp illuminates
- Ignition on/vehicle in service mode, verify a test light illuminates between B+ circuit terminal 2 and ground ⇒ If the test light does not illuminate and the circuit fuse is OK 3.1. Test the appropriate circuit for an open/high resistance: E13LA Front Headlamp – Left = Circuit 640 E13RA Front Headlamp – Right = Circuit 740 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 3.2. Verify there is voltage at the fuse. ⇒ If the test light does not illuminate and the circuit fuse is open 3.1. Test the appropriate circuit for a short to ground: E13LA Front Headlamp – Left = Circuit 640 E13RA Front Headlamp – Right = Circuit 740 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 3.2. Replace the appropriate E13 Headlamp Assembly. ⇓ If the test light illuminates
- Connect a test lamp between control circuit terminal 5 and ground.
- Verify the test lamp turns on and off when commanding the appropriate Daytime Running Lamp on and off with a scan tool. ⇒ If the test lamp is always OFF 5.1. Test the appropriate circuit for a short to ground: E13LA Front Headlamp – Left = Circuit 7538 E13RA Front Headlamp – Right = Circuit 7539 ⇒ If a short to ground is found, repair the fault on the circuit. ⇓ If a short to ground is not found 5.2. Test the appropriate circuit for an open/high resistance: E13LA Front Headlamp – Left = Circuit 7538 E13RA Front Headlamp – Right = Circuit 7539 ⇒ If an open/high resistance is found, repair the fault on the circuit. ⇓ If an open/high resistance is not found 5.3. Replace the K219 Lighting Control Module. ⇒ If the test lamp is always ON 5.1. Test the appropriate circuit for a short to voltage: E13LA Front Headlamp – Left = Circuit 7538 E13RA Front Headlamp – Right = Circuit 7539 ⇒ If a short to voltage is found, repair the fault on the circuit. ⇓ If a short to voltage is not found. 5.2. Replace the K219 Lighting Control Module. ⇓ If the test lamp turns ON and OFF
- Replace the appropriate E13 Headlamp Assembly. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Lighting Component Replacement Reference Control Module References for BCM replacement, programming, and setup