Pinpoint Test G: The Autolamps Are On Continuously
Autolamps
Pinpoint Tests
Pinpoint Test G: 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 for the autolamps request. The SJB also sends a voltage signal to the light sensor. 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 sends voltage to the exterior lamps if the ambient light conditions are dark. The light sensor determines the amount of light based on the input received from the ambient sky conditions. When the ambient level has reached a point (determined by the internal programming of the SJB), the SJB sends voltage to the headlamps, parking, and license plate lamps.
The SJB also sends a voltage signal to the windshield wiper motor. When the windshield wiper motor is on, the voltage signal is routed to ground.
If the SJB detects a fault with the headlamp switch inputs, the exterior lamps are faulted on.
- DTC B1696 (Autolamp On Circuit Short to Ground) - an on-demand DTC that sets when the SJB detects a short to ground from the autolamps on input circuit.
- DTC B1791 (Autolamp Sensor Input Circuit Open) - a continuous and on-demand DTC that sets when the SJB detects an open or short to voltage from the light sensor input circuit.
- DTC B2008 (Wipers On Signal Circuit Short to Ground) - an on-demand DTC that sets when the SJB detects a short to ground from the wipers on input circuit.
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Light sensor
- Headlamp switch
- Windshield wiper motor
- SJB
PINPOINT TEST G: 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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G1 CHECK THE RECORDED DTCs FROM THE SJB SELF-TEST
- Ignition OFF.
- Check the recorded results from the SJB self-test.
- Were any DTCs recorded?
Yes
For DTC B1696, GO to G4.
For DTC B1791, GO to G7.
For DTC B2008, GO to G11.
For all other DTCs, REFER to Diagnostic Trouble Code (DTC) Chart [1][2]Diagnostic Trouble Code Descriptions.
No
GO to G2.
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G2 CHECK THE SJB HEADLAMP SWITCH PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB headlamp switch PID (AUTOLMP) while moving the headlamp switch from the OFF to the AUTOLAMPS ON position.
- Do the headlamp switch positions agree with the PID?
Yes
GO to G3.
No
GO to G4.
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G3 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (NO DTC)
- Ignition OFF.
- Disconnect: Light Sensor C286.
- Ignition ON.
- 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. TEST the system for normal operation.
No
GO to G13.
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G4 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 G5.
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G5 CHECK THE AUTOLAMP REQUEST INPUT CIRCUIT FOR A SHORT TO GROUND
- Disconnect: SJB C2280d.
- 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 G6.
No
REPAIR circuit CLF19 (VT/GN) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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G6 CHECK THE AUTOLAMP REQUEST INPUT CIRCUIT FOR AN OPEN
- Measure the resistance between the headlamp switch C205-4, circuit CLF19 (VT/GN), harness side and the SJB C2280d-9, circuit CLF19 (VT/GN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to G13.
No
REPAIR circuit CLF19 (VT/GN) for an open. CLEAR the DTCs. REPEAT the self-test.
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G7 CHECK FOR VOLTAGE TO THE LIGHT SENSOR (DTC B1791)
- 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 G8.
No
GO to G9.
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G8 CHECK FOR VOLTAGE TO THE LIGHT SENSOR USING THE CONNECTOR GROUND
- Measure the voltage between the light sensor C286-2, circuit VLF14 (BU/BN), harness side and the light sensor C286-5, circuit GD145 (BK/BU), harness side.
- 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
REPAIR circuit GD145 (BK/BU) for an open. CLEAR the DTCs. REPEAT the self-test.
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G9 CHECK THE LIGHT SENSOR INPUT CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB C2280d.
- 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 G10.
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G10 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 C2280d-22, circuit VLF14 (BU/BN), harness side.
- Is the resistance less than 5 ohms?
Yes
GO to G13.
No
REPAIR circuit VLF14 (BU/BN) for an open. CLEAR the DTCs. REPEAT the self-test.
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G11 CHECK THE WINDSHIELD WIPER MOTOR
- Disconnect: Windshield Wiper Motor C125.
- 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 G12.
No
INSTALL a new windshield wiper motor. REFER to Wiper and Washer Systems. CLEAR the DTCs. REPEAT the self-test.
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G12 CHECK THE WINDSHIELD WIPER INPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: SJB C2280e.
- Measure the resistance between the windshield wiper motor C125-2, circuit CRW22 (WH/BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to G13.
No
REPAIR circuit CRW22 (WH/BU) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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G13 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 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. CLEAR the DTCs. REPEAT the self-test.
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