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

Parking, Rear and License Plate Lamps

Pinpoint Tests

Pinpoint Test P: 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 SJB sends a reference signal to the headlamp switch through circuit CLS34 (GY) to monitor for a parking lamp on request. When the headlamp switch is placed in the PARKING LAMPS ON position, the voltage signal is routed to ground. The SJB then energizes an internal relay, routing voltage through circuit CBP26 (BU/WH) to the rear and 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 lamp request input circuit.

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Headlamp switch
- SJB



PINPOINT TEST P: THE PARKING, REAR OR LICENSE PLATE LAMPS 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.

-------------------------------------------------
P1 CHECK THE RECORDED DTCs FROM THE SJB SELF-TEST


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

Yes
GO to P2.

No
GO to P4.

-------------------------------------------------
P2 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 P3.

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

-------------------------------------------------
P3 CHECK CIRCUIT CLS34 (GY) FOR A SHORT TO GROUND


- Disconnect: SJB C2280d.
- 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 P6.

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.

-------------------------------------------------
P4 CHECK CIRCUIT CBP26 (BU/WH) FOR A SHORT TO VOLTAGE (TO REAR LAMPS)


- Disconnect: SJB C2280a.
- Do any parking lamps continue to illuminate?

Yes
If the rear parking lamps continue to illuminate, REPAIR circuit CBP26 (BU/WH) for a short to voltage. TEST the system for normal operation.

If the front parking lamps continue to illuminate, GO to P5.

No
REPAIR circuit CAT17 (BN) for a short to voltage. TEST the system for normal operation.

-------------------------------------------------
P5 CHECK CIRCUIT CBP26 (BU/WH) FOR A SHORT TO VOLTAGE (TO FRONT LAMPS)


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

Yes
REPAIR the circuit. TEST the system for normal operation.

No
GO to P6.

-------------------------------------------------
P6 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. 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.

-------------------------------------------------