Pinpoint Test J: The Autolamps Are On Continuously
Autolamps
Pinpoint Tests
Pinpoint Test J: The Autolamps Are On Continuously
Refer to Wiring Diagram Set 85, 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 and a voltage signal to the light sensor.
When the headlamp switch is placed in the AUTOLAMPS ON position, the voltage signal to the headlamp switch is routed to ground. When the SJB detects the headlamp switch in the AUTOLAMPS ON position (with the ignition on), the SJB monitors the light sensor input with a separate voltage signal. The light sensor determines the amount of light based on the input received from the ambient lighting conditions. When the ambient light 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.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Light sensor
- Headlamp switch
- Windshield wiper motor
- SJB
PINPOINT TEST J: 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.
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J1 CHECK THE SJB AUTOLAMP ON REQUEST PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- 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 J5.
No
GO to J2.
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J2 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 the voltage greater than 10 volts?
Yes
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
No
GO to J3.
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J3 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 J4.
No
REPAIR circuit CLF19 (VT/GN) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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J4 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 J16.
No
REPAIR circuit CLF19 (VT/GN) for an open. CLEAR the DTCs. REPEAT the self-test.
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J5 CHECK THE SJB HEADLAMP SWITCH PIDs
NOTE: Make sure the headlamp switch is lined up in the correct position when monitoring the PIDs.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- NOTE: Only one PID should indicate ON at each headlamp switch position.
- While moving the headlamp switch through all positions, monitor the SJB headlamp switch input PIDs (HDLMP_OFF_CKT, HDLMP_PRK_CKT, HDLMP_ON_CKT).
- Do the headlamp switch positions agree with the PIDs (with only one PID indicating ON in each position)?
Yes
GO to J6.
No
GO to Pinpoint Test E Pinpoint Test E: The Low Beam(s) Are Always On.
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J6 CHECK THE RECORDED DTCs FROM THE SJB SELF-TEST
- Check the recorded results from the SJB self-test.
- Is DTC B2008, B1791 or B1793 present?
Yes
For DTC B2008, GO to J8.
For DTC B1791, GO to J10.
For DTC B1793, GO to J14.
No
GO to J7.
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J7 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (NO DTCs)
- Ignition OFF.
- Disconnect: Light Sensor C286.
- Ignition ON.
- Place the headlamp switch in the AUTOLAMPS ON position.
- Measure the voltage between the light sensor C286-2, 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 J16.
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J8 CHECK THE WINDSHIELD WIPER MOTOR
- Disconnect: Windshield Wiper Motor C125.
- Enter the following diagnostic mode on the scan tool: SJB Self-Test.
- Clear the DTCs and repeat the SJB self-test.
- Is DTC B2008 still present?
Yes
GO to J9.
No
INSTALL a new windshield wiper motor. REFER to Wiper and Washer Systems. TEST the system for normal operation.
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J9 CHECK WIPERS ON INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280f.
- Measure the resistance between the windshield wiper motor C125-2, circuit CRW01 (WH), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to J16.
No
REPAIR circuit CRW01 (WH) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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J10 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.
- Measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- Is the voltage approximately 5 volts?
Yes
GO to J13.
No
GO to J11.
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J11 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB C2280b.
- Ignition ON.
- Measure the voltage between the light sensor C286-2, 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 J12.
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J12 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR AN OPEN
- Ignition OFF.
- 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.
- Is the resistance less than 5 ohms?
Yes
GO to J16.
No
REPAIR circuit VLF14 (BU/BN) for an open. CLEAR the DTCs. REPEAT the self-test.
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J13 CHECK THE LIGHT SENSOR GROUND CIRCUIT FOR AN OPEN
- Measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and the light sensor C286-4, circuit GD114 (BK/BU), 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 GD114 (BK/BU) for an open. CLEAR the DTCs. REPEAT the self-test.
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J14 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (DTC B1793)
- Ignition OFF.
- Disconnect: Light Sensor C286.
- Ignition ON.
- Place the headlamp switch in the AUTOLAMPS ON position.
- Measure the voltage between the light sensor C286-2, 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 J15.
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J15 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280b.
- Measure the resistance between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to J16.
No
REPAIR circuit VLF14 (BU/BN) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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J16 CHECK FOR CORRECT SJB OPERATION
- 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 Body Control Systems. 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.
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