Pinpoint Test I: All The STOPLAMPS Are Inoperative

WARNING: This page is about a different car, the 2012 Ford Pickup. 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.

I1 CHECK FOR VOLTAGE TO THE STOPLAMP SWITCH
- Ignition OFF.
- Disconnect: Stoplamp Switch C278.
- Measure the voltage between the stoplamp switch C278-4, circuit SBB46 (BN/RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between Stoplamp Switch C278-4, Circuit SBB46 (BN/RD), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
  - Yes : GO to I2.
  - No : VERIFY the BJB fuse 46 (10A) is OK. If OK, REPAIR circuit SBB46 (BN/RD) for an open. TEST the system for normal operation. If not OK, REFER to the Wiring Diagrams information to identify the possible causes of the circuit short.
I2 BYPASS THE STOPLAMP SWITCH
- Connect a fused jumper wire between the stoplamp switch C278-4, circuit SBB46 (BN/RD), harness side and the stoplamp switch C278-1, circuit CCB08 (VT/WH), harness side.
  
  Fig 2: Connecting Fused Jumper Wire Between Stoplamp Switch C278-4, Circuit SBB46 (BN/RD) And C278-1, Circuit CCB08 (VT/WH)
  Courtesy of FORD MOTOR CO.
- Are the stoplamps illuminated?
  - Yes : REMOVE the jumper wire. INSTALL a new stoplamp switch. REFER to STOPLAMP SWITCH . TEST the system for normal operation.
  - No : LEAVE the jumper wire connected. GO to I3.
I3 CHECK THE STOPLAMP SWITCH SIGNAL TO THE BCM
- Disconnect: BCM C2280B.
- Measure the voltage between the BCM C2280B-28, circuit CCB08 (VT/WH), harness side and ground.
  
  Fig 3: Measuring Voltage Between BCM C2280B-28, Circuit CCB08 (VT/WH), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
  - Yes : REMOVE the jumper wire. GO to I4.
  - No : REMOVE the jumper wire. REPAIR circuit CCB08 (VT/ WH) for an open. TEST the system for normal operation.
I4 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.