Pinpoint Test D: No Power In Start

WARNING: This page is about a different car, the 2010 Lincoln MKX and 2010 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.

D1 CHECK THE IGNITION SWITCH
- Carry out the Ignition Switch - Electrical Component Test.
- Does the ignition switch test OK?
- Yes: GO to D2 .
- No: INSPECT the connector for corrosion, pushed-out pins or spread terminals. REPAIR as necessary. If the connector is OK, INSTALL a new ignition switch. REFER to IGNITION SWITCH . TEST the system for normal operation.
D2 CHECK THE IGNITION SWITCH START OUTPUT CIRCUIT FOR AN OPEN
- Disconnect: Ignition Switch C250.
- Disconnect: PCM C175B.
- Disconnect: Start Diode.
- Measure the resistance between ignition switch C250-7, circuit CDC35 (BU/WH), harness side and:
  - PCM C175B-9, circuit CDC35 (BU/WH), harness side.
  - start diode, circuit CDC35 (BU/WH), input side.
    
    Fig 1: Checking Ignition Switch Start Output Circuit For Open
    Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes: GO to D3 .
- No: REPAIR circuit CDC35 (BU/WH). TEST the system for normal operation.
D3 CHECK THE IGNITION SWITCH START OUTPUT CIRCUIT FOR A SHORT TO GROUND
- Measure the resistance between ignition switch C250-7, circuit CDC35 (BU/WH), harness side and ground.
  
  Fig 2: Measuring Resistance Between Ignition Switch C250-7, Circuit CDC35 (BU/WH), Harness Side And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance greater than 10,000 ohms?
- Yes: GO to D4 .
- No: REPAIR circuit CDC35 (BU/WH). TEST the system for normal operation.
D4 ISOLATE THE START DIODE
- Test the starter diode.
- Is the starter diode OK?
- Yes: GO to D5
- No: INSTALL a new diode. TEST the system for normal operation.
D5 CHECK THE SJB START CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280B.
- Disconnect: Starter Relay.
- Measure the resistance between SJB C2280B-32, circuit CDC35 (BU/WH), harness side and:
  - PCM C175B-35, circuit CDC35 (BU/WH), harness side.
  - starter diode, circuit CDC35 (BU/WH), output side.
  - starter relay, circuit CDC35 (BU/WH).
    
    Fig 3: Checking SJB Start Circuit For Open
    Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes: GO to D6
- No: REPAIR circuit CDC35 (BU/WH). TEST the system for normal operation.
D6 CHECK FOR CORRECT SJB OPERATION
- Check SJB connector C2280B for:
  - corrosion.
  - pushed-out pins.
  - spread terminals.
- Connect: SJB C2280B.
- Make sure the connector seats correctly, then operate the system and verify the concern is still present.
- Is the concern still present?
- Yes: INSTALL a new SJB . REFER to MULTIFUNCTION ELECTRONIC MODULES . CLEAR the DTCs. REPEAT the self-test.
- No: The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector.