Pinpoint Test M: The Turn Signal Lamps Are Inoperative

WARNING: This page is about a different car, the 2010 Mercury Milan, 2010 Lincoln MKZ, and 2010 Ford Fusion. 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.

M1 CHECK FOR CORRECT HIGH BEAM OPERATION
- Place the headlamp switch in the HEADLAMPS ON position.
- Place the multifunction switch in the HIGH BEAM position while observing the high beam headlamps.
- Do the high beams illuminate?
- Yes: PLACE the headlamp switch in the OFF position.
  For Fusion, GO to M2.
  
  For Milan or MKZ, VERIFY the SJB fuse 6 (20A) is OK. If OK, GO to M3. If not OK, REFER to the appropriate SYSTEM WIRING DIAGRAMS article to identify the possible causes of the circuit short.
- No: PLACE the headlamp switch in the OFF position. Go To PINPOINT TEST A .
M2 CHECK FOR CORRECT STOPLAMP OPERATION
- Apply and release the brake pedal.
- Do the stoplamps operate correctly?
- Yes: GO to M3.
- No: REFER to STOPLAMPS .
M3 BYPASS THE MULTIFUNCTION SWITCH
- Ignition OFF.
- Disconnect: Multifunction Switch C202.
- For an inoperative LH turn signal, connect a fused jumper wire between the multifunction switch C202-2, circuit CLS39 (VT/WH), harness side and the multifunction switch C202-8, circuit GD116 (BK/VT), harness side.
  
  Fig 1: Connecting Fused Jumper Wire Between Multifunction Switch C202-2 & Multifunction Switch C202-8
  Courtesy of FORD MOTOR CO.
- For an inoperative RH turn signal, connect a fused jumper wire between the multifunction switch C202-3, circuit CLS41 (GY/YE), harness side and the multifunction switch C202-8, circuit GD116 (BK/VT), harness side.
  
  Fig 2: Connecting Fused Jumper Wire Between Multifunction Switch C202-3 & Multifunction Switch C202-8
  Courtesy of FORD MOTOR CO.
- Ignition ON.
- Do the turn signals in question flash on and off?
- Yes: REMOVE the jumper wire. INSTALL a new multifunction switch. REFER to REMOVAL AND INSTALLATION . TEST the system for normal operation.
- No: REMOVE the jumper wire. GO to M4.
M4 CHECK THE TURN SIGNAL REQUEST INPUT CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280b.
- For an inoperative LH turn signal, measure the resistance between the multifunction switch C202-2, circuit CLS39 (VT/WH), harness side and the SJB C2280b-42, circuit CLS39 (VT/WH), harness side.
  
  Fig 3: Measuring Resistance Between Multifunction Switch C202-2 & SJB C2280B-42
  Courtesy of FORD MOTOR CO.
- For an inoperative RH turn signal, measure the resistance between the multifunction switch C202-3, circuit CLS41 (GY/YE), harness side and the SJB C2280b-29, circuit CLS41 (GY/YE), harness side.
  
  Fig 4: Measuring Resistance Between Multifunction Switch C202-3 & SJB C2280B-29
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes: GO to M5.
- No: REPAIR circuit CLS39 (VT/WH) (LH turn signal) or circuit CLS41 (GY/YE) (RH turn signal) for an open. TEST the system for normal operation.
M5 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 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.