Pinpoint Test O: The Parking, Rear Or License Plate Lamps Are On Continuously
Parking, Rear and License Plate Lamps
Pinpoint Tests
Pinpoint Test O: 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
Refer to Wiring Diagram Set 140, Customer Access 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/WH) to the rear and front parking lamps.
- DTC B1578 (Lamp Park Input Circuit Short to Ground) - an on-demand DTC that may set 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
- Body builder equipment
- SJB
PINPOINT TEST O: THE PARKING, REAR OR LICENSE PLATE LAMPS ARE ON CONTINUOUSLY
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O1 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 O2.
No
GO to O4.
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O2 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 O3.
No
INSTALL a new headlamp switch. REFER to Headlamp Switch Service and Repair. CLEAR the DTCs. REPEAT the self-test.
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O3 CHECK THE PARKING LAMP REQUEST INPUT CIRCUIT FOR A SHORT TO GROUND
- Disconnect: SJB C2280b.
- Measure the resistance between the headlamp switch C205-2, circuit CLS34 (GY), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to O8.
No
REPAIR circuit CLS34 (GY) for a short to ground. CLEAR the DTCs. REPEAT the self-test.
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O4 CHECK THE REAR PARKING LAMPS VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB C2280d.
- Ignition ON.
- Do the rear parking lamps continue to illuminate?
Yes
For wagon, REPAIR circuit CLS30 (VT/WH) for a short to voltage. TEST the system for normal operation.
For cutaway and stripped chassis vehicles, GO to O5.
No
GO to O6.
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O5 ISOLATE THE SHORT TO VOLTAGE IN THE REAR PARKING LAMPS VOLTAGE SUPPLY CIRCUIT
- Ignition OFF.
- Disconnect: Body Builder C432.
- Ignition ON.
- Do the rear parking lamps continue to illuminate?
Yes
The vehicle is operating correctly. REFER to the body builder information to continue diagnosis.
No
REPAIR circuit CLS30 (VT/WH) for a short to voltage. TEST the system for normal operation.
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O6 CHECK THE FRONT PARKING LAMPS VOLTAGE SUPPLY CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: SJB C2280e.
- Ignition ON.
- Do the front parking lamps continue to illuminate?
Yes
For wagon, REPAIR circuit CLS30 (VT/WH) for a short to voltage. TEST the system for normal operation.
For cutaway and stripped chassis vehicles, GO to O7.
No
GO to O8.
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O7 ISOLATE THE SHORT TO VOLTAGE IN THE FRONT PARKING LAMPS VOLTAGE SUPPLY CIRCUIT
- Ignition OFF.
- Disconnect: Body Builder C1010.
- Ignition ON.
- Do the front parking lamps continue to illuminate?
Yes
The vehicle is operating correctly. REFER to the body builder information to continue diagnosis.
No
REPAIR circuit CLS30 (VT/WH) for a short to voltage. TEST the system for normal operation.
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O8 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.
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