Pinpoint Test T: The Reversing Lamps Are On Continuously

Reversing Lamps

Pinpoint Test T: The Reversing Lamps Are On Continuously

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).

This pinpoint test is intended to diagnose the following:

- Wiring, terminals or connectors
- Auto-dimming interior mirror
- Digital TR sensor



PINPOINT TEST T: THE REVERSING LAMPS ARE ON CONTINUOUSLY

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

NOTICE: Use the correct probe adapter(s) when making measurements. Failure to use the correct probe adapter(s) may damage the connector.

-------------------------------------------------
T1 CHECK THE DIGITAL TR SENSOR


- Ignition OFF.
- If equipped with a fire suppression system, depower the fire suppression system. Refer to Fire Suppression System. Procedures
- Disconnect: Digital TR Sensor C167.
- Connect: Battery.
- Ignition ON.
- Do the reversing lamps continue to illuminate?

Yes
If equipped with an auto-dimming interior mirror, GO to T2 .

If not equipped with an auto-dimming interior mirror, REPAIR circuit 140 (BK/PK) for a short to voltage. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the fire suppression system. REFER to Fire Suppression System. Procedures

No
INSTALL a new digital TR sensor. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the fire suppression system. REFER to Fire Suppression System. Procedures

-------------------------------------------------
T2 CHECK CIRCUIT 140 (BK/PK) FOR A SHORT TO VOLTAGE


- Ignition OFF.
- Disconnect: Auto-Dimming Interior Mirror C911.
- Ignition ON.
- Do the reversing lamps continue to illuminate?

Yes
REPAIR the circuit. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the fire suppression system. REFER to Fire Suppression System. Procedures

No
INSTALL a new auto-dimming interior mirror. TEST the system for normal operation. If equipped with a fire suppression system, REPOWER the fire suppression system. REFER to Fire Suppression System. Procedures

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