Pinpoint Test A: No Communication With The Smart Junction Box (SJB)

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

CAUTION: Use the correct probe adaptor(s) when making measurements. Failure to use the correct probe adaptor(s) may damage the connector.

A1 CHECK THE SJB GROUND CIRCUIT
- Key in OFF position.
- Disconnect: SJB C2280a.
- Measure the resistance between the SJB C2280a-21, circuit 570 (BK/WH), harness side and ground.
  
  Fig 1: Checking SJB Ground Circuit
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
Yes : GO to A2.

No : REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. CARRY OUT the data link diagnostics test.
A2 CHECK THE SJB POWER SUPPLY CIRCUIT 785 (BK/LG)
- Disconnect: SJB C2280b.
- Key in ON position.
- For Escape Mariner, measure the voltage between the SJB C2280b-32, circuit 785 (BK/LG), harness side and ground.
  
  Fig 2: Checking SJB Power Supply Circuit 785 (BK/LG) (1 Of 2)
  Courtesy of FORD MOTOR CO.
- For Escape Hybrid measure the voltage between the SJB C2280b-4, circuit 1052 (TN/BK), harness side and ground.
  
  Fig 3: Checking SJB Power Supply Circuit 785 (BK/LG) (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
Yes : REFER to MODULE COMMUNICATIONS NETWORK to continue communication diagnosis.

No : VERIFY the (SJB) fuse 17 (15A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the self-test. CARRY OUT the data link diagnostics test.