Pinpoint Test Q: The Parking, Rear Or License Plate Lamps Are On Continuously

Parking, Rear and License Plate Lamps

Pinpoint Tests

Pinpoint Test Q: The Parking, Rear Or License Plate Lamps Are On Continuously

Refer to Wiring Diagram Set 92, Parking, Rear and License Lamps for schematic and connector information. Diagrams By Number

Normal Operation

The Smart Junction Box (SJB) monitors the parking lamp request input from the headlamp switch through circuit CLS34 (GY). The SJB provides a ground for the parking lamp relay coil (integral to the SJB) when a request for the parking lamps is received. When the parking lamp relay is energized, voltage is routed through circuit CLS30 (VT) to the rear parking lamps and through circuit CLS30 (VT/WH) to the front parking lamps.

- DTC B1578 (Lamp Park Input Circuit Short to Ground) - an on-demand DTC that sets when the SJB detects a short to ground from the parking lamps on input circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Headlamp switch
- SJB



PINPOINT TEST Q: THE PARKING, REAR OR LICENSE PLATE LAMPS ARE ON CONTINUOUSLY

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Q1 USE THE RECORDED DTCs FROM THE SJB SELF-TEST


- Check the recorded results from the SJB self-test.
- Is DTC B1578 present?

Yes
GO to Q2.

No
GO to Q4.

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Q2 CHECK THE HEADLAMP SWITCH


- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Carry out the headlamp switch component test.

- Is the headlamp switch OK?

Yes
GO to Q3.

No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.

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Q3 CHECK THE PARKING LAMPS ON INPUT CIRCUIT FOR A SHORT TO GROUND


- Disconnect: SJB C2280b.
- Measure the resistance between the headlamp switch C205-5, circuit CLS34 (GY), harness side and ground.




- Is the resistance greater than 10,000 ohms?

Yes
GO to Q6.

No
REPAIR circuit CLS34 (GY) for a short to ground. CLEAR the DTCs. REPEAT the self-test.

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Q4 CHECK THE SJB REAR PARKING LAMPS OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: SJB C2280d.
- Ignition ON.
- Do the rear parking lamps continue to illuminate?

Yes
REPAIR circuit CLS30 (VT) for a short to voltage. TEST the system for normal operation.

No
GO to Q5.

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Q5 CHECK THE SJB FRONT PARKING LAMPS OUTPUT CIRCUIT FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: SJB C2280e.
- Ignition ON.
- Do the front parking lamps continue to illuminate?

Yes
REPAIR circuit CLS30 (VT/WH) for a short to voltage. TEST the system for normal operation.

No
GO to Q6.

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Q6 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. 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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