Pinpoint Test H: The Autolamps Are On Continuously
Autolamps
Pinpoint Test H: The Autolamps Are On Continuously
Refer to Wiring Diagram Set 85 (Fusion/Milan/MKZ, Fusion Hybrid, Milan Hybrid, MKZ Hybrid), Headlamps/Autolamps for schematic and connector information. Diagrams By Number
Normal Operation
The Smart Junction Box (SJB) sends a voltage signal to the headlamp switch to monitor the request for autolamps and a voltage signal to the light sensor to determine the ambient light level.
When the headlamp switch is placed in the AUTOLAMPS ON position, the voltage signal is routed to ground. When the SJB detects the headlamp switch in the AUTOLAMPS ON position, the SJB monitors the light sensor input. The light sensor determines the amount of light based on the input received from the ambient lighting conditions. When the ambient level has reached a point (determined by the internal programming of the SJB), the SJB provides voltage to the headlamps, parking and license plate lamps.
The SJB also monitors the windshield wiper motor status by sending a voltage signal to the wiper/washer module. When the windshield wiper is on (except during a mist wipe or while the wipers are on to clear washer fluid during a wash condition), the wiper/washer module grounds the circuit to indicate to the SJB that the wipers are on.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Light sensor
- Headlamp switch
- Wiper/washer module
- SJB
PINPOINT TEST H: THE AUTOLAMPS 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.
-------------------------------------------------
H1 CHECK THE SJB AUTOLAMP ON REQUEST PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- NOTE: Make sure the headlamp switch is in the OFF position.
- While placing the headlamp switch in the AUTOLAMPS ON and then OFF position, monitor the SJB headlamp switch PID (HDLMP_AUT_CKT).
- Does the PID indicate ON with the headlamp switch in the AUTOLAMPS ON position and OFF when the headlamp switch is in the OFF position?
Yes
GO to H5.
No
GO to H2.
-------------------------------------------------
H2 CHECK FOR A VOLTAGE SIGNAL TO THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Measure the voltage between the headlamp switch C205-4, circuit CLF19 (VT/GN), harness side and ground.
- Is voltage greater than 10 volts?
Yes
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. TEST the system for normal operation.
No
GO to H3.
-------------------------------------------------
H3 CHECK THE AUTOLAMPS REQUEST INPUT CIRCUIT FOR A SHORT TO GROUND
- Disconnect: SJB C2280b.
- Measure the resistance between the headlamp switch C205-4, circuit CLF19 (VT/GN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to H4.
No
REPAIR circuit CLF19 (VT/GN) for a short to ground. TEST the system for normal operation.
-------------------------------------------------
H4 CHECK THE AUTOLAMPS REQUEST INPUT CIRCUIT FOR AN OPEN
- Measure the resistance between the headlamp switch C205-4, circuit CLF19 (VT/GN), harness side and the SJB C2280b-50, circuit CLF19 (VT/GN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to H15.
No
REPAIR circuit CLF19 (VT/GN) for an open. TEST the system for normal operation.
-------------------------------------------------
H5 USE THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB self-test.
- Was DTC B2008, B1791 or B1793 recorded?
Yes
For DTC B2008, GO to H7.
For DTC B1791, GO to H9.
For DTC B1793, GO to H13.
No
GO to H6.
-------------------------------------------------
H6 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (NO DTCs)
- Ignition OFF.
- Disconnect: Light Sensor C286 or C287.
- Ignition ON.
- Place the headlamp switch in the AUTOLAMPS ON position.
- For vehicles with automatic temperature control, measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- For vehicles with manual temperature control, measure the voltage between the light sensor C287-A, circuit VLF14 (BU/BN), harness side and ground.
- Is the voltage approximately 5 volts?
Yes
INSTALL a new light sensor. REFER to Light Sensor Service and Repair. TEST the system for normal operation.
No
GO to H15.
-------------------------------------------------
H7 CHECK THE WIPER/WASHER MODULE
- Ignition OFF.
- Disconnect: Wiper/Washer Module C2157.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Repeat the SJB self-test.
- Is DTC B2008 still present?
Yes
GO to H8.
No
INSTALL a new wiper/washer module. REFER to Wipers and Washers Service and Repair. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
H8 CHECK THE WIPERS ON INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280f.
- Measure the resistance between the wiper/washer module C2157-2, circuit CRW01 (WH), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to H15.
No
REPAIR circuit CRW01 (WH) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
H9 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (DTC B1791)
- Ignition OFF.
- Disconnect: Light Sensor C286.
- Ignition ON.
- Place the headlamp switch in the AUTOLAMPS ON position.
- For vehicles with automatic temperature control, measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- For vehicles with manual temperature control, measure the voltage between the light sensor C287-A, circuit VLF14 (BU/BN), harness side and ground.
- Is the voltage approximately 5 volts?
Yes
GO to H12.
No
GO to H10.
-------------------------------------------------
H10 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Place the headlamp switch in the OFF position.
- Disconnect: SJB C2280b.
- Ignition ON.
- For vehicles with automatic temperature control, measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- For vehicles with manual temperature control, measure the voltage between the light sensor C287-A, circuit VLF14 (BU/BN), harness side and ground.
- Is any voltage present?
Yes
REPAIR circuit VLF14 (BU/BN) for a short to voltage. CLEAR the DTCs. REPEAT the self-test.
No
GO to H11.
-------------------------------------------------
H11 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- For vehicles with automatic temperature control, measure the resistance between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and the SJB C2280b-46, circuit VLF14 (BU/BN), harness side.
- For vehicles with manual temperature control, measure the resistance between the light sensor C287-A, circuit VLF14 (BU/BN), harness side and the SJB C2280b-46, circuit VLF14 (BU/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to H15.
No
REPAIR circuit VLF14 (BU/BN) for an open. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
H12 CHECK FOR VOLTAGE TO THE LIGHT SENSOR USING THE CONNECTOR GROUND
- For vehicles with automatic temperature control, measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and the light sensor C286-4, circuit GD116 (BK/VT), harness side.
- For vehicles with manual temperature control, measure the voltage between the light sensor C287-A, circuit VLF14 (BU/BN), harness side and the light sensor C287-B, circuit GD116 (BK/VT), harness side.
- Is the voltage approximately 5 volts?
Yes
INSTALL a new light sensor. REFER to Light Sensor Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
REPAIR circuit GD116 (BK/VT) for an open. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
H13 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (DTC B1793)
- Disconnect: Light Sensor C286.
- Ignition ON.
- Place the headlamp switch in the AUTOLAMPS ON position.
- For vehicles with automatic temperature control, measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- For vehicles with manual temperature control, measure the voltage between the light sensor C287-A, circuit VLF14 (BU/BN), harness side and ground.
- Is the voltage approximately 5 volts?
Yes
INSTALL a new light sensor. REFER to Light Sensor Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
GO to H14.
-------------------------------------------------
H14 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280b.
- For vehicles with automatic temperature control, measure the resistance between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- For vehicles with manual temperature control, measure the resistance between the light sensor C287-A, circuit VLF14 (BU/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to H15.
No
REPAIR circuit VLF14 (BU/BN) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
-------------------------------------------------
H15 CHECK FOR CORRECT SJB OPERATION
- Ignition OFF.
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB 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 SJB. REFER to Multifunction Electronic Modules Service and Repair. 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.
-------------------------------------------------