Pinpoint Test W: The Reversing Lamps Are On Continuously
Reversing Lamps
Pinpoint Tests
Pinpoint Test W: The Reversing Lamps Are On Continuously
Refer to Wiring Diagram Set 93, Reversing Lamps for schematic and connector information. Diagrams By Number
Normal Operation
Voltage is supplied from the Battery Junction Box (BJB) fuse 26 (15A) to the coil side of the reversing lamps relay through circuit CBB26 (BU/WH). The reversing lamps relay switch side is supplied voltage by the BJB fuse 7 (10A) through circuit SBB07 (WH/RD). The reversing lamps relay coil ground is controlled by the PCM through circuit CLS28 (BU/WH). When the transaxle is in REVERSE (R), the PCM completes the ground, energizing the reversing lamps relay. When the reversing lamps relay is energized, voltage is routed to the reversing lamps and the auto-dimming interior rear view mirror (if equipped) through circuit CLS10 (GN/BN).
Automatic Transaxle
The PCM sets digital Transmission Range (TR) sensor related DTCs if any concerns exist with inputs from the TR sensor.
Manual Transaxle
The PCM sends a voltage reference signal to the reversing lamps switch through circuit CET47 (BU). When the transaxle is in REVERSE (R), the voltage reference signal is routed to back to the PCM through the signal return circuit RE242 (GN).
This pinpoint test is intended to diagnose the following:
- Wiring, terminals or connectors
- Reversing lamps relay
- Reversing lamp switch (manual transaxle)
- Interior rear view mirror
- PCM
PINPOINT TEST W: 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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W1 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 an auto-dimming interior rear view mirror, GO to W2.
If not equipped with an auto-dimming interior rear view mirror, REPAIR circuit CLS10 (GN/BN) for a short to voltage. TEST the system for normal operation.
No
GO to W3.
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W2 CHECK CIRCUIT CLS10 (GN/BN) FOR A SHORT TO VOLTAGE
- Ignition OFF.
- Disconnect: Interior Rear View Mirror C911.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
INSTALL a new interior rear view mirror. TEST the system for normal operation.
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W3 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 W4.
No
REMOVE the known good relay. INSTALL a new reversing lamps relay. TEST the system for normal operation.
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W4 CHECK CIRCUIT CLS28 (BU/WH) FOR A SHORT TO GROUND
- Ignition OFF.
- Connect: Reversing Lamps Relay.
- Disconnect: PCM C175t.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
REPAIR the circuit. TEST the system for normal operation.
No
For vehicles with an automatic transaxle, GO to W5.
For vehicles with a manual transaxle, GO to W6.
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W5 CHECK THE DIGITAL TR SENSOR INPUT
- Ignition OFF.
- Connect: PCM C175t.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: PCM DataLogger.
- Monitor the PCM transmission gear status PID (TR) while placing the gear selector lever through all its positions.
- Does the PID agree with the gear selection?
Yes
GO to W8.
No
REFER to Transmission Control Systems to continue diagnosis of the digital TR sensor. Testing and Inspection
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W6 CHECK THE REVERSING LAMP SWITCH
- Ignition OFF.
- Connect: PCM C175t.
- Disconnect: Reversing Lamp Switch C169.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
Yes
GO to W7.
No
INSTALL a new reversing lamp switch. REFER to Reversing Lamp Switch Service and Repair. TEST the system for normal operation.
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W7 CHECK CIRCUIT CET47 (BU) FOR A SHORT TO GROUND
- Ignition OFF.
- Disconnect: PCM C175t.
- Measure the resistance between the reversing lamp switch C169-2, circuit CET47 (BU), harness side and ground.
- Is the resistance greater than 10,000 ohms?
Yes
GO to W8.
No
REPAIR the circuit. TEST the system for normal operation.
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W8 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the PCM 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 PCM. 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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