Pinpoint Test X: The Reversing Lamps Are On Continuously

WARNING: This page is about a different car, the 2010 Mercury Mariner and 2010 Ford Escape. However, it is still accessible from the selected car via links, so may be relevant.

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

X1 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 interior rear view mirror, GO to X2 .
  If not equipped with an interior rear view mirror, REPAIR circuit CBB07 (GN/BU) for a short to voltage. TEST the system for normal operation.
- No: GO to X3.
X2 CHECK THE REAR VIEW MIRROR
- Ignition OFF.
- Disconnect: Interior Rear View Mirror C9039, C9030 or C9012.
- Ignition ON.
- Do the reversing lamps continue to illuminate?
- Yes: REPAIR circuit CBB07 (GN/BU) for a short to voltage. TEST the system for normal operation.
- No: INSTALL a new interior rear view mirror. REFER to REAR VIEW MIRRORS . TEST the system for normal operation.
X3 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 X4 .
- No: REMOVE the known good relay. INSTALL a new reversing lamps relay. TEST the system for normal operation.
X4 CHECK THE REVERSING LAMPS RELAY COIL GROUND CONTROLLED CIRCUIT FOR A SHORT TO GROUND
- Ignition OFF.
- Connect: Reversing Lamps Relay.
- Disconnect: Reversing Lamp Switch C169 (Manual Transaxle).
- Disconnect: PCM C175t (Automatic Transaxle).
- Ignition ON.
- Do the reversing lamps continue to illuminate?
- Yes: REPAIR circuit CLS28 (BU/WH) for a short to ground. TEST the system for normal operation.
- No: For vehicles with an automatic transaxle, GO to X5 .
  For vehicles with a manual transaxle, INSTALL a new reversing lamp switch. REFER to REVERSING LAMP SWITCH . TEST the system for normal operation.
X5 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. REFER to ELECTRONIC ENGINE CONTROLS - 2.5L , ELECTRONIC ENGINE CONTROLS - 3.0L (4V) or ELECTRONIC ENGINE CONTROLS - HYBRID . 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.