Pinpoint Test T: The Fog Lamps Are Inoperative

WARNING: This page is about a different car, the 2006 Mercury Montego, 2006 Ford Freestyle, and 2006 Ford Five Hundred. However, it is still accessible from the selected car via links, so may be relevant.

T1 USE THE RECORDED DIAGNOSTIC TROUBLE CODES (DTCs) FROM THE SJB SELF-TEST
- Key in OFF position.
- Using the recorded results from the SJB self-test:
- Was DTC B2030 present?
Yes: GO to T2.

No: GO to T6.
T2 CHECK CIRCUIT 1205 (BK) FOR AN OPEN
- Disconnect: Fog Lamp Relay C1007.
- Measure the resistance between the fog lamp relay C1007-2, circuit 1205 (BK), harness side and ground.
  
  Fig 1: Measuring Resistance Between Fog Lamp Relay C1007-2, Circuit 1205 (BK), Harness Side & Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to T3.

No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
T3 CHECK THE FOG LAMP RELAY (DTC B2030)
- Carry out the fog lamp relay component test, refer to SYSTEM WIRING DIAGRAMS - FIVE HUNDRED , SYSTEM WIRING DIAGRAMS - FREESTYLE and SYSTEM WIRING DIAGRAMS - MONTEGO for component testing.
- Is the fog lamp relay OK?
Yes: GO to T4.

No: INSTALL a new fog lamp relay. CLEAR the DTCs. REPEAT the self-test.
T4 CHECK CIRCUIT 1347 (DB/WH) FOR AN OPEN
- Connect: Fog Lamp Relay C1007.
- Disconnect: SJB 02280a.
- Connect a fused (5A) jumper wire between the SJB C2280a-29, circuit 1231 (RD/WH), harness side and the SJB C2280a-5, circuit 1347 (DB/WH), harness side.
- Do the fog lamps illuminate?
Yes: REMOVE the jumper wire. GO to T5.

No: REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test.
T5 CHECK CIRCUIT 1407 (LB/OG) FOR A SHORT TO GROUND
- Disconnect: SJB C2280d.
- Disconnect: Headlamp Switch C205.
- Measure the resistance between the headlamp switch C205-3, circuit 1407 (LB/OG), harness side and ground.
  
  Fig 3: Measuring Resistance Between Headlamp Switch C205-3, Circuit 1407 (LB/OG), Harness Side & Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
Yes: GO to T11.

No: REPAIR the circuit. TEST the system for normal operation.
T6 CHECK THE FOG LAMP SWITCH INPUT
- Key in ON position.
- Enter the following diagnostic mode on the scan tool: SJB Headlamp Switch PID.
- Monitor the SJB headlamp switch PID and engage the fog lamp switch.
- Does the PID indicate the fog lamp switch is active?
Yes: GO to T9.

No: GO to T7.
T7 CHECK CIRCUIT 1406 (YE/LG) FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Key in OFF position.
- Disconnect: Headlamp Switch C205.
- Disconnect: SJB C2280d.
- Measure the resistance between the headlamp switch C205-6, circuit 1406 (YE/LG), harness side and the SJB C2280d-9, circuit 1406 (YE/LG), harness side.
  
  Fig 4: Checking Circuit 1406 (YE/LG)
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes: GO to T8.

No: REPAIR the circuit. TEST the system for normal operation.
T8 CHECK THE HEADLAMP SWITCH
- Carry out the headlamp switch component test. Refer to COMPONENT TESTING article for component testing.
- Is the headlamp switch OK?
Yes: GO to T11.

No: INSTALL a new headlamp switch. TEST the system for normal operation.
T9 CHECK CIRCUIT 477 (LB/BK) FOR AN OPEN
- Place the headlamp switch in the OFF position.
- Key in OFF position.
- Disconnect: Fog Lamp Relay C1007.
- Measure the voltage between the fog lamp relay C1007-3, circuit 477 (LB/BK), harness side and ground.
  
  Fig 5: Measuring Voltage Between Fog Lamp Relay C1007-3, Circuit 477 (LB/BK), Harness Side & Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes: GO to T10.

No: VERIFY the BJB fuse 24 (15A) is OK. If OK, REPAIR the circuit. TEST the system for normal operation.
T10 CHECK CIRCUIT 1776 (TN/OG) FOR AN OPEN
- Connect a fused (15A) jumper wire between the fog lamp relay C1007-3, circuit 477 (LB/BK), harness side and the fog lamp relay C1007-5, circuit 1776 (TN/OG), harness side.
  
  Fig 6: Checking Circuit 1776 (TN/OG)
  Courtesy of FORD MOTOR CO.
- Do the fog lamps illuminate?
Yes: INSTALL a new fog lamp relay. TEST the system for normal operation.

No: REPAIR the circuit. TEST the system for normal operation.
T11 CHECK FOR CORRECT SJB OPERATION

Disconnect all the SJB connectors.
Check for:
- corrosion
- 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 REMOVAL AND INSTALLATION . 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. CLEAR the DTCs. REPEAT the self-test.