Pinpoint Test W: The Reversing Lamps Are On Continuously

WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

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

W1 CHECK THE REVERSING LAMPS RELAY OUTPUT
- Key in OFF position.
- Disconnect: Reversing Lamps Relay
- Key in ON position.
- Do the reversing lamps continue to illuminate?
1. YES : Go to W2.
2. NO : Go to W4.
W2 CHECK THE REAR VIEW MIRROR
- Key in OFF position.
- Disconnect: Interior Rear View Mirror C911 or C9012 (if equipped)
- Key in ON position.
- Do the reversing lamps continue to illuminate?
1. YES : If equipped with rear parking aid, go to W3.
  If not equipped with rear parking aid, REPAIR circuit CBB07 (GN/BU) for a short to voltage. TEST the system for normal operation.
2. NO : INSTALL a new interior rear view mirror. REFER to REAR VIEW MIRRORS article. TEST the system for normal operation.
W3 CHECK CIRCUIT CBB07 (GN/BU) FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Disconnect: Parking Aid Module C4014
- Key in ON position.
- Do the reversing lamps continue to illuminate?
1. YES : REPAIR the circuit. TEST the system for normal operation.
2. NO : Go to W6.
W4 CHECK THE REVERSING LAMPS RELAY
- Key in OFF position.
- Carry out the reversing lamps relay component test. Refer to appropriate COMPONENT TESTING article.
- Is the reversing lamps relay OK?
1. YES : Go to W5.
2. NO : INSTALL a new reversing lamps relay. TEST the system for normal operation.
W5 CHECK CIRCUIT CLS28 (BU/WH) FOR A SHORT TO GROUND
- Key in OFF position.
- Disconnect: Digital TR Sensor C167 (automatic transaxle - except Hybrid)
- Disconnect: Reversing Lamp Switch C169 (manual transaxle)
- Disconnect: PCM C175e (Hybrid only)
- Key in ON position.
- Do the reversing lamps continue to illuminate?
1. YES : REPAIR the circuit. TEST the system for normal operation.
2. NO : For non-Hybrid vehicles with an automatic transaxle, INSTALL a new digital TR sensor. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION EXTERNAL CONTROLS - CD4E article. TEST the system for normal operation.
  For non-Hybrid vehicles with a manual transaxle, INSTALL a new reversing lamp switch. REFER to Reversing Lamp Switch . TEST the system for normal operation.
  
  For Hybrid vehicles, go to W7.
W6 CHECK FOR CORRECT PARKING AID MODULE OPERATION
- Disconnect the parking aid module connector.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect the parking aid module connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?
1. YES : INSTALL a new parking aid module. REFER to PARKING AID article. TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR any DTCs. REPEAT the self-test.
W7 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?
1. YES : INSTALL a new PCM. REFER to ELECTRONIC ENGINE CONTROLS - HYBRID article. TEST the system for normal operation.
2. NO : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.