Pinpoint Test Q: The Parking, Rear And License Plate Lamps Are On Continuously
Parking, Rear and License Plate Lamps
Pinpoint Test Q: The Parking, Rear And License Plate Lamps Are On Continuously
Refer to Wiring Diagram Set 92, Parking, Rear and License Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The Central Junction Box (CJB) supplies voltage to the Lighting Control Module (LCM) through circuit 195 (TN/WH). When a request for the parking lamps is detected, the LCM provides voltage to the parking and license plate lamps through circuit 14 (BN).
- DTC B1578 (Lamp Park Input Short to Ground) - an on-demand DTC that sets when the LCM detects a short to ground from the parking lamps on input circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Headlamp switch
- LCM
PINPOINT TEST Q: THE PARKING, REAR AND LICENSE PLATE LAMPS ARE ON CONTINUOUSLY
NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
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Q1 CHECK THE RECORDED DTCs FROM THE LCM SELF-TEST
- Use the recorded results from the LCM self-test.
- Is DTC B1578 present?
Yes
GO to Q2.
No
GO to Q4.
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Q2 CHECK THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205a.
- Carry out the headlamp switch component test.
- Is the headlamp switch OK?
Yes
GO to Q3.
No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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Q3 CHECK CIRCUIT 1032 (WH/BK) FOR A SHORT TO GROUND
- Disconnect: LCM C2145a.
- Measure the resistance between the headlamp switch C205a-5, circuit 1032 (WH/BK), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to Q5.
No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
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Q4 CHECK CIRCUIT 14 (BN) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: LCM C2145d.
- Ignition ON.
- Do the exterior lamps continue to illuminate?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
GO to Q5.
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Q5 CHECK FOR CORRECT LCM OPERATION
- Ignition OFF.
- Disconnect all the LCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the LCM connectors and make sure they seat correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new LCM. TEST the system for normal operation.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.
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