Pinpoint Test Q: Both Fog Lamps Are Inoperative

WARNING: This page is about a different car, the 2013 Ford F-550 Super Duty, 2013 Ford F-450 Super Duty, 2013 Ford F-350 Super Duty, and 2013 Ford F-250 Super Duty. 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.

Q1 CHECK THE FOG LAMP SWITCH PID
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: SCCM DataLogger.
- Monitor the SCCM fog lamp switch PID while engaging the fog lamp switch.
- Does the PID indicate the fog lamp switch is on?
- Yes : VERIFY the BCM fuse 47 (15A) is OK. If OK, GO to Q4. If not OK, REFER to the SYSTEM WIRING DIAGRAMS to identify the possible causes of the circuit short.
- No : GO to Q2.
Q2 CHECK FOR A VOLTAGE SIGNAL TO THE HEADLAMP SWITCH
- Ignition OFF.
- Disconnect: Headlamp Switch C205.
- Measure the voltage between the headlamp switch C205-5, circuit CLF21 (GY/VT), harness side and ground.
  
  Fig 1: Measuring Voltage Between Headlamp Switch C205-5, Circuit CLF21 (GY/VT) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 5 volts?
- Yes : INSTALL a new headlamp switch. REFER to HEADLAMP SWITCH . TEST the system for normal operation.
- No : GO to Q3.
Q3 CHECK THE FOG LAMP REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SCCM C2414a.
- Measure the resistance between the headlamp switch C205-5, circuit CLF21 (GY/VT), harness side and the SCCM C2414a-1, circuit CLF21 (GY/VT), harness side.
  
  Fig 2: Measuring Resistance Between Headlamp Switch C205-5, Circuit CLF21 (GY/VT) And SCCM C2414A-1, Circuit CLF21 (GY/VT)
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to Q6.
- No : REPAIR circuit CLF21 (GY/VT) for an open. TEST the system for normal operation.
Q4 BYPASS THE BCM
NOTE: If the fuse in the jumper wire fails, refer to the SYSTEM WIRING DIAGRAMS to identify the possible causes of the circuit short.
- Ignition OFF.
- Disconnect: BCM C2280e.
- Connect a fused jumper wire between the BCM C2280e-5, circuit CLF12 (BN/YE), harness side and battery positive.
  
  Fig 3: Connecting Fused Jumper Wire Between BCM C2280E-5, Circuit CLF12 (BN/YE) And Battery Positive
  Courtesy of FORD MOTOR CO.
- Do the fog lamps illuminate?
- Yes : REMOVE the jumper wire. GO to Q7.
- No : LEAVE the jumper wire connected. GO to Q5.
Q5 CHECK FOR VOLTAGE TO THE FOG LAMP
- Disconnect: LH Fog Lamp C152.
- Measure the voltage between the LH fog lamp C152-A, circuit CLF12 (BN/YE), harness side and ground.
  
  Fig 4: Measuring Voltage Between LH Fog Lamp C152-A, Circuit CLF12 (BN/YE) And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : REMOVE the jumper wire. REPAIR circuit GD122 (BK) 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.
Q6 CHECK FOR CORRECT SCCM OPERATION
- Disconnect all the SCCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the SCCM 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 SCCM. REFER to STEERING COLUMN SWITCHES .
  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.
Q7 CHECK FOR CORRECT BCM OPERATION
- Disconnect all the BCM connectors.
- Check for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all the BCM 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 BCM. 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.