Pinpoint Test X: The Reversing Lamps Are On Continuously
Reversing Lamps
Pinpoint Tests
Pinpoint Test X: The Reversing Lamps Are On Continuously
Refer to Wiring Diagram Set 93, Reversing Lamps for schematic and connector information. Diagrams By Number
Normal Operation
The PCM monitors the transaxle gear status. When the PCM detects the transaxle is in REVERSE (R), the PCM provides ground for the reversing lamps relay coil.
Voltage is supplied when the ignition is in the RUN or START position (from the PCM relay output) to the coil side of the reversing lamps relay and at all times from the Battery Junction Box (BJB) fuse 26 (20A) to the switched side of the reversing lamps relay. When the reversing lamps relay is energized, voltage is routed through the BJB fuse 38 (10A) for the trailer tow reversing lamps and through the BJB fuse 36 (10A) to the reversing lamps and the auto-dimming interior mirror.
- DTC P1910 (Reverse Lamp Control Circuit/Open) - sets when the PCM detects no voltage from the reversing lamp relay coil ground control circuit (if the coil ground control circuit is short to ground).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Reversing lamps relay
- Auto-dimming interior mirror
- PCM
PINPOINT TEST X: THE REVERSING 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.
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X1 CHECK FOR PCM TR SENSOR DTCs FROM THE SELF-TEST
- Review the DTCs from the PCM Key ON Engine OFF (KOEO) self-test.
- Are any TR sensor DTCs present?
Yes
REFER to Automatic Transaxle/Transmission - 6F50/6F55 Testing and Inspection.
No
GO to X2.
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X2 CHECK THE REVERSING LAMPS RELAY OUTPUT
- Ignition OFF.
- Disconnect: Reversing Lamps Relay.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
If equipped with trailer tow, GO to X3.
If not equipped with trailer tow, GO to X4.
No
GO to X6.
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X3 CHECK THE TRAILER TOW REVERSING LAMP CIRCUIT FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: BJB Fuse 38 (10A).
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
GO to X4.
No
REPAIR circuit CAT03 (GN/BN) for a short to voltage. TEST the system for normal operation.
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X4 CHECK THE AUTO-DIMMING INTERIOR MIRROR FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Auto-Dimming Interior Mirror C911 or C9012.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
GO to X5.
No
INSTALL new auto-dimming interior mirror. REFER to Rear View Mirrors Interior Rear View Mirror. TEST the system for normal operation.
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X5 ISOLATE THE SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: BJB Fuse 36 (10A).
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
REPAIR circuit CLS10 (GN/BN) between the fuse and the reversing lamps. TEST the system for normal operation.
No
REPAIR circuit CLS10 (GN/BN) between the reversing lamps relay and BJB fuse(s). TEST the system for normal operation.
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X6 CHECK THE REVERSING LAMPS RELAY
- Ignition OFF.
- Substitute a known good relay.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
REMOVE the known good relay. GO to X7.
No
REMOVE the known good relay. INSTALL a new reversing lamps relay. TEST the system for normal operation.
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X7 CHECK THE REVERSING LAMPS RELAY OUTPUT CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Connect: Reversing Lamps Relay.
- Disconnect: PCM C175t or C1381t.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
REPAIR circuit CLS28 (BU/WH) for a short to voltage. TEST the system for normal operation.
No
GO to X8.
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X8 CHECK FOR CORRECT PCM OPERATION
- Disconnect the PCM connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the PCM connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
Yes
INSTALL a new PCM. REFER to Electronic Engine Controls Service and Repair. 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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