Pinpoint Test R: Both Fog Lamps Are Inoperative

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.

R1 CHECK THE HEADLAMP SWITCH PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SJB DataLogger.
- Monitor the SJB headlamp switch PID (FOG SW) while engaging the fog lamp switch.
- Does the PID indicate the fog lamp switch is on?
- Yes: VERIFY the SJB fuse 21 (15A) is OK. If OK, GO to R4. If not OK, REFER to the appropriate SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short.
- No: GO to R2 .
R2 CHECK FOR VOLTAGE TO THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Measure the voltage between the headlamp switch C205-6, circuit CLF29 (BN), harness side and ground.
  
  Fig 1: Measuring Voltage Between Headlamp Switch C205-6, Circuit CLF29 (BN), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: INSTALL a new headlamp switch. REFER to HEADLAMP SWITCH . TEST the system for normal operation.
- No: GO to R3 .
R3 CHECK THE FOG LAMP REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280b.
- Measure the resistance between the headlamp switch C205-6, circuit CLF29 (BN), harness side and the SJB C2280b-49, circuit CLF29 (BN), harness side.
  
  Fig 2: Checking Fog Lamp Request Input Circuit For An Open
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes: GO to R6.
- No: REPAIR circuit CLF29 (BN) for an open. TEST the system for normal operation.
R4 BYPASS THE SJB
- Ignition OFF.
- Disconnect: SJB C2280e.
- Connect a fused jumper wire between the SJB C2280e-1, circuit CDC34 (WH/OG), harness side and the SJB C2280e-3, circuit CLF12 (BN/YE), harness side.
  
  Fig 3: Connecting Fused Jumper Wire Between SJB C2280E-1, Circuit CDC34 (WH/OG) And SJB C2280E-3, Circuit CLF12 (BN/YE)
  Courtesy of FORD MOTOR CO.
- Ignition ON.
- Do the fog lamps illuminate?
- Yes: REMOVE the jumper wire. GO to R6.
- No: LEAVE the jumper wire connected. GO to R5 .
R5 CHECK FOR VOLTAGE TO THE FOG LAMPS
- Disconnect: Inoperative Fog Lamps.
- Ignition ON.
- Place the headlamp switch in the PARKING LAMPS ON position and engage the fog lamp switch.
- For Escape, measure the voltage between the LH fog lamp C1322-B, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C1323-B, circuit CLF12 (BN/YE), harness side and ground.
  
  Fig 4: Checking Voltage To Fog Lamps (1 Of 2)
  Courtesy of FORD MOTOR CO.
- For Mariner, measure the voltage between the LH fog lamp C152-2, circuit CLF12 (BN/YE), harness side and ground; or between the RH fog lamp C162-2, circuit CLF12 (BN/YE), harness side and ground.
  
  Fig 5: Checking Voltage To Fog Lamps (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes: REMOVE the jumper wire. REPAIR circuit GD120 (BK/GN) for an open. TEST the system for normal operation.
- No: REMOVE the jumper wire. REPAIR circuit CLF12 (BN/YE) for an open. TEST the system for normal operation.
R6 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the SJB 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 SJB . REFER to MULTIFUNCTION ELECTRONIC MODULES . 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.