Pinpoint Test P: One Or More Parking, Rear Or License Plate Lamps Is Inoperative
Parking, Rear and License Plate Lamps
Pinpoint Tests
Pinpoint Test P: One Or More Parking, Rear or License Plate Lamps Is Inoperative
Refer to Wiring Diagram Set 92, Parking, Rear and License Lamps for schematic and connector information. Diagrams By Number
Normal Operation
When the headlamp switch is placed in the PARKING LAMPS ON position, the Smart Junction Box (SJB) provides a ground for the parking lamp relay coil (integral to the SJB). When the parking lamp relay is energized, voltage is routed through circuits CLS30 (VT) to the rear parking lamps and CLS30 (VT/WH) to the front parking lamps. Ground is provided to the rear parking and license plate lamps through circuits GD147 (BK/VT) and GD148 (BK/YE). Ground is provided to the front parking and side marker lamps through circuit GD120 (BK/GN) and GD123 (BK/GY).
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Bulb holder
- Rear lamp jumper harness
- Rear lamp assembly
- SJB
PINPOINT TEST P: ONE OR MORE PARKING, REAR OR LICENSE PLATE LAMPS IS INOPERATIVE
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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P1 DETERMINE IF ALL THE PARKING LAMPS ARE INOPERATIVE
- Ignition OFF.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Are all the parking lamps inoperative?
Yes
PLACE the headlamp switch in the OFF position. VERIFY the SJB fuse 22 (15A) is OK. If OK, GO to P7. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the circuit short.
No
If all the front parking lamps are inoperative, GO to P2.
If all the rear parking and license plate lamps are inoperative, GO to P3.
For all others, GO to P4.
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P2 CHECK THE SJB FRONT PARKING LAMPS OUTPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280e.
- Connect a fused jumper wire between the SJB C2280e-1, circuit CDC34 (WH/OG), harness side and the SJB C2280e-6, circuit CLS30 (VT/WH), harness side.
- Ignition ON.
- Do the front parking lamps illuminate?
Yes
REMOVE the jumper wire. GO to P7.
No
REMOVE the jumper wire. REPAIR the circuit. TEST the system for normal operation.
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P3 CHECK THE SJB REAR PARKING LAMPS OUTPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280d.
- Connect a fused jumper wire between the positive battery terminal and the SJB C2280d-20, circuit CLS30 (VT), harness side.
- Do the rear parking lamps illuminate?
Yes
REMOVE the jumper wire. GO to P7.
No
REMOVE the jumper wire. REPAIR the circuit. TEST the system for normal operation.
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P4 CHECK FRO VOLTAGE TO THE INOPERATIVE PARKING LAMP
- Disconnect: Inoperative Lamp.
- Place the headlamp switch in the PARKING LAMPS ON position.
- Measure the voltage between the inoperative lamp, harness side and ground as follows:
Taurus:
Sable:
Taurus X:
- Is the voltage greater than 10 volts?
Yes
For the license plate lamps, REPAIR circuit CLS30 (VT) for an open. TEST the system for normal operation.
For all others, GO to P5.
No
REPAIR the circuit in question. TEST the system for normal operation.
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P5 CHECK FOR VOLTAGE TO THE INOPERATIVE PARKING LAMP USING THE CONNECTOR GROUND
- Measure the voltage between the inoperative lamp connector, harness side as follows:
Taurus:
Sable:
Taurus X:
- Is the voltage greater than 10 volts?
Yes
For any front lamp or license plate lamp, INSTALL a new bulb holder. TEST the system for normal operation.
For Taurus rear lamp, REPAIR or INSTALL a new rear lamp jumper harness. TEST the system for normal operation.
For Sable or Taurus X rear lamp, GO to P6.
No
REPAIR the ground circuit in question for an open. TEST the system for normal operation.
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P6 CHECK THE REAR LAMP JUMPER HARNESS
- Place the headlamp switch in the OFF position.
- Inspect the rear lamp jumper harness for opens
- Is the rear lamp jumper harness OK?
Yes
INSTALL a new rear lamp assembly. REFER to Rear Lamp Assembly Service and Repair. TEST the system for normal operation.
No
REPAIR or INSTALL a new rear lamp jumper harness. TEST the system for normal operation.
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P7 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.
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