Pinpoint Test G: The AUTOLAMPS Are On Continuously
WARNING: This page is about a different car, the 2009 Mercury Grand Marquis and 2009 Ford Crown Victoria. However, it is still accessible from the selected car via links, so may be relevant.
CAUTION:
Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.
- G1 CHECK THE LCM HEADLAMP SWITCH PIDs
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: LCM DataLogger
- Monitor the LCM headlamp switch PID (HD_LMP_SW) while moving the headlamp switch through all positions.
- Do the headlamp switch positions agree with the PID?
- G2 CHECK THE HEADLAMP SWITCH
- Key in OFF position.
- Disconnect: Headlamp Switch C205a
- Carry out the headlamp switch component test. Refer to COMPONENT TESTING article.
- Is the headlamp switch OK?
- YES : Go to G3.
- NO : INSTALL a new headlamp switch. REFER to Headlamp Switch . CLEAR the DTCs. REPEAT the self-test.
- G3 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Measure the resistance between the headlamp switch C205a-7, circuit 57 (BK), harness side and ground.
- Is the resistance less than 5 ohms?
- YES : Go to G4.
- NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
- G4 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR AN OPEN
- Disconnect: LCM C2145a and C2145b
- Measure the resistance between the headlamp switch, harness side and the LCM, harness side as follows:
Headlamp Switch Connector-Pin LCM Connector-Pin Circuit C205a-4 C2145a-15 220 (VT/OG) C205a-9 C2145b-2 1400 (TN/WH) C205a-5 C2145a-9 1032 (WH/BK) C205a-10 C2145a-3 1033 (RD/YE) - Are the resistances less than 5 ohms?
- YES : Go to G5.
- NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
- G5 CHECK THE HEADLAMP SWITCH INPUT CIRCUITS FOR A SHORT TO GROUND
- Measure the resistance between the headlamp switch, harness side and ground as follows:
Headlamp Switch Connector-Pin Circuit C205a-4 220 (VT/OG) C205a-10 1033 (RD/YE) - Are the resistances greater than 10,000 ohms?
- YES : Go to G13.
- NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test.
- Measure the resistance between the headlamp switch, harness side and ground as follows:
- G6 CHECK THE LCM WINDSHIELD WIPER MOTOR PID
- Enter the following diagnostic mode on the diagnostic tool: LCM DataLogger
- Monitor the LCM windshield wiper motor PID (WPRMTRST1).
- Does the PID indicate the windshield wiper motor is active?
- G7 CHECK THE WINDSHIELD WIPER MOTOR
- Key in OFF position.
- Disconnect: Windshield Wiper Motor C125
- Key in ON position.
- Enter the following diagnostic mode on the diagnostic tool: LCM DataLogger
- Monitor the LCM windshield wiper motor PID (WPRMTRST1).
- Does the PID indicate the windshield wiper motor ACTIVE?
- YES : Go to G8.
- NO : INSTALL a new windshield wiper motor. REFER to WIPERS & WASHERS article. CLEAR the DTCs. REPEAT the self-test.
- G8 CHECK CIRCUIT 28 (BK/PK) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: LCM C2145d
- Measure the resistance between the windshield wiper motor C125-2, circuit 28 (BK/PK), harness side and ground.
- Is the resistance greater than 10,000 ohms?
- YES : Go to G13.
- NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
- G9 CHECK CIRCUIT 676 (PK/OG) FOR AN OPEN
- Key in OFF position.
- Disconnect: Light Sensor C287
- Measure the resistance between the light sensor C287-5, circuit 676 (PK/OG), harness side and ground.
- Is the resistance less than 5 ohms?
- YES : Go to G10.
- NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
- G10 CHECK CIRCUIT 218 (WH/VT) FOR A SHORT TO VOLTAGE
- Disconnect: LCM C2145a
- Key in ON position.
- Measure the voltage between the light sensor C287-2, circuit 218 (WH/VT), harness side and ground.
- Is any voltage present?
- YES : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
- NO : Go to G11.
- G11 CHECK CIRCUIT 218 (WH/VT) FOR AN OPEN
- Key in OFF position.
- Measure the resistance between the light sensor C287-2, circuit 218 (WH/VT), harness side and the LCM C2145a-1, circuit 218 (WH/VT), harness side.
- Is the resistance less than 5 ohms?
- YES : Go to G12.
- NO : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
- G12 CHECK FOR VOLTAGE TO THE LIGHT SENSOR
- Connect: LCM C2145a
- Key in ON position.
- Place the headlamp switch in the AUTOLAMPS ON position.
- Measure the voltage between the light sensor C287-2, circuit 218 (WH/VT), harness side and ground.
- Is the voltage approximately 5 volts?
- YES : INSTALL a new light sensor. REFER to Light Sensor . CLEAR the DTCs. REPEAT the self-test.
- NO : Go to G13.
- G13 CHECK FOR CORRECT LCM OPERATION
- Key in OFF position.
- 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. REFER to MULTIFUNCTION ELECTRONIC MODULES article. 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.