Pinpoint Test R: Both Reversing Lamps Are Inoperative
Reversing Lamps
Pinpoint Test R: Both Reversing Lamps Are Inoperative
Refer to Wiring Diagram Set 93, Reversing Lamps for schematic and connector information. Diagrams By Number
Normal Operation
When the ignition switch is in the RUN position, voltage is provided to the digital Transmission Range (TR) sensor from the Central Junction Box (CJB) through circuit 1789 (VT/WH). When the transmission is placed in REVERSE(R), the digital TR sensor routes voltage to the reversing lamps through circuit 140 (BK/PK). The reversing lamps share a ground with the license plate lamps through circuit 57 (BK).
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- Digital TR sensor
PINPOINT TEST R: BOTH REVERSING LAMPS ARE 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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R1 CHECK CIRCUIT 57 (BK) FOR AN OPEN
- Ignition OFF.
- Place the headlamp switch in the PARKING LAMPS ON position and observe the license plate lamps.
- Do the license plate lamps illuminate?
Yes
GO to R2.
No
REPAIR circuit 57 for an open. TEST the system for normal operation.
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R2 CHECK THE DIGITAL TR SENSOR ADJUSTMENT
WARNING: If equipped with fire suppression system, refer to Fire Suppression System for Important Safety Warnings. Failure to follow this instruction may result in serious personal injury. Procedures
- Place the headlamp switch in the OFF position.
- If equipped with a fire suppression system, depower the system. Refer to Fire Suppression System. Procedures
- Check the digital TR sensor adjustment.
- Is the digital TR sensor adjusted correctly?
Yes
GO to R3.
No
ADJUST the digital TR sensor. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the system. REFER to Fire Suppression System. Procedures
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R3 CHECK CIRCUIT 1789 (VT/WH) FOR AN OPEN
- Disconnect: Digital TR Sensor C167.
- Connect: Battery.
- Ignition ON.
- Measure the voltage between the digital TR sensor C167-9, circuit 1789 (VT/WH), harness side and ground.
- Is the voltage greater than 10 volts?
Yes
GO to R4.
No
VERIFY the CJB fuse 20 (10A) is OK. If OK, REPAIR the circuit for an open. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the system. REFER to Fire Suppression System. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. Procedures
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R4 CHECK CIRCUIT 140 (BK/PK) FOR AN OPEN
- Ignition OFF.
- Connect a fused jumper wire between the digital TR sensor C167-9, circuit 1789 (VT/WH), harness side and the digital TR sensor C167-11, circuit 140 (BK/PK), harness side.
- Ignition ON.
- Do the reversing lamps illuminate?
Yes
REMOVE the jumper wire. INSTALL a new digital TR sensor. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the system. REFER to Fire Suppression System. Procedures
No
REMOVE the jumper wire. REPAIR the circuit. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the system. REFER to Fire Suppression System. Procedures
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