Pinpoint Test M: The Reversing Lamps Are On Continuously

WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. However, it is still accessible from the selected car via links, so may be relevant.

M1 DETERMINE THE TRANSMISSION TYPE
- Check the vehicle transmission type.
- Is the vehicle equipped with a TorqShift transmission?
- Yes : GO to M3.
- No : GO to M2.
M2 CHECK THE DIGITAL TR SENSOR
- Key in OFF position.
- Disconnect: Digital TR Sensor C167.
- Key in ON position.
- Do the reversing lamps continue to illuminate?
- Yes : REPAIR circuit 140 (BK/PK). TEST the system for normal operation.
- No : INSTALL a new digital TR sensor. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70W/4R75W . TEST the system for normal operation.
M3 CHECK CIRCUIT 140 (BK/PK) FOR A SHORT TO VOLTAGE
- Key in OFF position.
- Disconnect: Reversing Lamp Relay C121.
- Key in ON position.
- Do the reversing lamps continue to illuminate?
- Yes : REPAIR the circuit. TEST the system for normal operation.
- No : GO to M4.
M4 CHECK THE REVERSING LAMP RELAY
- Key in OFF position.
- Carry out the reversing lamp relay component test. Refer to COMPONENT TESTING for component testing.
- Is the reversing lamp relay OK?
- Yes : GO to M5.
- No : INSTALL a new reversing lamp relay. TEST the system for normal operation.
M5 CHECK CIRCUIT 1362 (DG/OG) FOR A SHORT TO GROUND
- Key in OFF position.
- Connect: Reversing Lamp Relay C121.
- Disconnect: PCM C175a (Gasoline Engine) or C176b (Diesel Engine).
- Key in ON position.
- Do the reversing lamps continue to illuminate?
- Yes : REPAIR the circuit. TEST the system for normal operation.
- No : GO to M6.
M6 CHECK FOR CORRECT PCM OPERATION
- Disconnect all the PCM connectors.
- Check for:
  - corrosion
  - 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 - GASOLINE ENGINES or ELECTRONIC ENGINE CONTROLS - GASOLINE ENGINES . 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.