Pinpoint Test A: No Power In All Ignition Switch Positions - Vehicles With An Ignition Switch

WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

NOTE: Use the Flex Probe Kit for all test connections to prevent damage to the wiring terminals. Do not use standard multi-meter probes.

A1 CHECK THE IGNITION SWITCH
- Ignition OFF.
- Disconnect: Ignition Switch C250 .
- Carry out the IGNITION SWITCH .
  Refer to OEM WIRING DIAGRAMS COMPONENT TESTING .
Is the ignition switch OK?
- Yes : GO to A2 .
- No : INSTALL a new ignition switch. REFER to IGNITION SWITCH . CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
A2 CHECK FOR POWER TO THE IGNITION SWITCH
- Measure the voltage between ignition switch C250-4 , circuit SBP28 (BU/RD), harness side and ground.
  
  Fig 1: Measuring Voltage Between Ignition Switch C250-4, Circuit SBP27 (BU/RD) And Ground
  Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts?
- Yes : GO to A4.
- No : VERIFY BCM fuse 28 (15A) Is OK. If OK, GO to A3 . If not OK, REFER to the SYSTEM WIRING DIAGRAMS to identify the possible cause of the circuit short. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.
A3 CHECK FOR POWER TO BCM FUSE 28 (15A)
- Measure the voltage between BCM fuse 28 (15A), circuit SBP28 (BU/RD), output cavity and ground.
  
  Fig 2: Measuring Voltage Between BCM Fuse 28 (15A), Circuit SBP28 (BU/RD), Output Cavity And Ground
  Courtesy of FORD MOTOR CO.
Is the voltage greater than 10 volts?
- Yes : REPAIR circuit SBP28 (BU/RD). CLEAR the DTCs. REPEAT the self-test. TEST the system for normal operation.
- No : VERIFY MEGA fuse (120A) is OK. If OK, REPAIR circuit SDC02 (RD). If not OK, REFER to the SYSTEM WIRING DIAGRAMS to identify the possible cause of the circuit short. CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.

A4 CHECK THE BCM IGNITION SWITCH INPUT CIRCUITS FOR AN OPEN

Disconnect: BCM C2280B .

Measure the resistance between ignition switch C250 , harness side and BCM C2280B , harness side as follows:

Ignition Switch	Circuit	BCM
C250-6	CDC33 (VT/GN)	C2280B-35
C250-1	CDC34 (WH/OG)	C2280B-29
C250-7	CDC35 (BU/WH)	C2280B-47

Fig 3: Checking BCM Ignition Switch Input Circuits For Open

Courtesy of FORD MOTOR CO.

Are the resistances less than 5 ohms?

Yes : GO to A5 .
No : REPAIR the affected circuit(s). CLEAR the DTC. REPEAT the self-test. TEST the system for normal operation.

A5 CHECK FOR CORRECT BCM OPERATION
- Disconnect all BCM connectors.
- Check the connectors for:
  - corrosion
  - damaged pins
  - pushed-out pins
- Connect all BCM connectors and make sure they are seated correctly.
- Connect: Ignition Switch C250 .
- 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 . CLEAR the DTCs. REPEAT the self-test. 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. TEST the system for normal operation.