Pinpoint Test L: The Reversing Lamps Are Inoperative

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.

L1 CHECK CIRCUIT 57 (BK) FOR AN OPEN

Key in OFF position.
Disconnect: Inoperative Reversing Lamp.

Measure the resistance between an inoperative reversing lamp, harness side and ground as follows:

CONNECTOR PIN SPECIFICATION

Inoperative Reversing Lamp	Connector-Pin	Circuit
LH reversing lamp (except stripped chassis)	C451-1	57 (BK)
RH reversing lamp (except stripped chassis)	C461-1	57 (BK)
LH reversing lamp (stripped chassis)	C414-2	57 (BK)
RH reversing lamp (stripped chassis)	C417-2	57 (BK)

Is the resistance less than 5 ohms?

Yes : GO to L2.
No : REPAIR the circuit. TEST the system for normal operation.

L2 DETERMINE THE TRANSMISSION TYPE
- Connect: Inoperative Reversing Lamp.
- Check the vehicle transmission type.
- Is the vehicle equipped with a TorqShift transmission?
- Yes : GO to L5.
- No : GO to L3.
L3 CHECK CIRCUIT 296 (WH/VT) FOR AN OPEN (WITHOUT TORQSHIFT)
- Disconnect: Digital TR Sensor C167.
- Key in ON position.
- Measure the voltage between the digital TR sensor C167-9, circuit 296 (WH/VT), harness side and ground.
  
  Fig 1: Measuring Voltage Between Digital TR Sensor And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to L4.
- No : VERIFY the CJB fuse 12 (15A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation.
L4 CHECK THE DIGITAL TR SENSOR
- Key in OFF position.
- Connect a fused (15A) jumper wire between the digital TR sensor C167-9, circuit 296 (WH/VT), harness side and the digital TR sensor C167-11, circuit 140 (BK/PK), harness side.
  
  Fig 2: Connecting Fused (15A) Jumper Wire Between Digital TR Sensor Circuits 296 And 140
  Courtesy of FORD MOTOR CO.
- Key in ON position.
- Do the reversing lamps illuminate?
- Yes : INSTALL a new digital TR sensor. REFER to AUTOMATIC TRANSAXLE/TRANSMISSION - 4R70W/4R75W . TEST the system for normal operation.
- No : REPAIR circuit 140 (BK/PK). TEST the system for normal operation.
L5 CHECK FOR PCM DIAGNOSTIC TROUBLE CODES (DTCs)
- Key in ON position.
- Carry out the PCM self-test.
- Retrieve and record any PCM DTCs.
- Are any PCM DTCs retrieved?
- Yes : See INTRODUCTION - GASOLINE and/or INTRODUCTION -- 6.0L DIESEL articles to continue diagnosis of the PCM DTCs.
- No : GO to L6.
L6 CHECK THE REVERSING LAMP RELAY
- Key in OFF position.
- Disconnect: Reversing Lamp Relay C121.
- Carry out the reversing lamp relay component test. Refer to COMPONENT TESTING for component testing.
- Is the reversing lamp relay OK?
- Yes : GO to L7.
- No : INSTALL a new reversing lamp relay. TEST the system for normal operation.
L7 CHECK CIRCUIT 296 (WH/VT) FOR AN OPEN (WITH TORQSHIFT)
- Key in ON position.
- Measure the voltage between the reversing lamp relay C121-3, circuit 296 (WH/VT), harness side and ground.
  
  Fig 3: Measuring Voltage Between Reversing Lamp Relay Circuit 296 And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to L8.
- No : VERIFY the CJB fuse 12 (15A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation.
L8 CHECK CIRCUIT 140 (BK/PK) FOR AN OPEN
- Key in OFF position.
- Install a fused (5A) jumper wire between the reversing lamp relay C121-5 circuit 140 (BK/PK), harness side and the reversing lamp relay C121-3 circuit 296 (WH/VT), harness side.
  
  Fig 4: Installing Fused (5A) Jumper Wire Between Reversing Lamp Relay Circuits 140 And 296
  Courtesy of FORD MOTOR CO.
- Key in ON position.
- Do the reversing lamps illuminate?
- Yes : REMOVE the jumper wire. GO to L9.
- No : REPAIR the circuit. TEST the system for normal operation.
L9 CHECK CIRCUIT 361 (RD) FOR AN OPEN
- Measure the voltage between the reversing lamp relay C121-2, circuit 361 (RD), harness side and ground.
  
  Fig 5: Measuring Voltage Between Reversing Lamp Relay Circuit 361 And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to L10.
- No : REPAIR the circuit. TEST the system for normal operation.
L10 CHECK CIRCUIT 1362 (DG/OG) FOR AN OPEN
- Key in OFF position.
- Disconnect: PCM C175a (Gasoline Engine) or C176b (Diesel Engine).
- Measure the resistance between the PCM C175a-24, circuit 1362 (DG/OG), harness side and the reversing lamp relay C121-1, circuit 1362 (DG/OG), harness side; or between the PCM C176b-3, circuit 1362 (DG/OG), harness side and the reversing lamp relay C121-1, circuit 1362 (DG/OG), harness side.
  
  Fig 6: Measuring Resistance Between PCM Circuit 1362 And Reversing Lamp Relay Circuit 1362
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to L11.
- No : REPAIR the circuit. TEST the system for normal operation.
L11 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 - DIESEL ENGINE . 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.