Pinpoint Test Q: The Parking, Rear Or License Plate Lamps Are On Continuously
WARNING: This page is about a different car, the 2006 Mercury Grand Marquis and 2006 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
- Q1 CHECK THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCs) FROM THE LCM
- Use the recorded results from the LCM self-test.
- Is DTC B1578 present?
Yes : GO to Q2.
No : GO to Q4.
- Q2 VERIFY DTC B1578
- Key in OFF position.
- Disconnect: LCM C2145a.
- Measure the resistance between the LCM C2145a-9, circuit 1032 (WH/BK), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes : GO to Q5.
No : GO to Q3.
- Q3 CHECK CIRCUIT 1032 (WH/BK) FOR A SHORT TO GROUND
- Disconnect: Headlamp Switch C205a.
- Measure the resistance between the LCM C2145a-9, circuit 1032 (WH/BK), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes : INSTALL a new headlamp switch. REFER to HEADLAMP SWITCH . CLEAR the DTCs. REPEAT the self-test.
No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
- Q4 CHECK CIRCUIT 14 (BN) FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Disconnect: LCM C2145d.
- Key in ON position.
- Do the exterior lamps continue to illuminate?
Yes : REPAIR the circuit. TEST the system for normal operation.
No : GO to Q5.
- Q5 CHECK FOR CORRECT LCM OPERATION
- Key in OFF position.
- Disconnect all the LCM connectors.
- Check for:
- corrosion
- 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. REFER to MULTIFUNCTION ELECTRONIC MODULES . 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.