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Pinpoint Test C: The Smart Junction Box (SJB) Does Not Respond To The Diagnostic Tool

WARNING: This page is about a different car, the 2005 Mercury Sable and 2005 Ford Taurus. However, it is still accessible from the selected car via links, so may be relevant.
  1. C1 CHECK SJB C2280C FOR DAMAGE 
    • Key in OFF position.
    • Disconnect: SJB C2280c.
    • Is the SJB C2280C OK? 
    • Yes  : GO to  C2.
    • No  : REPAIR the SJB C2280c. CARRY OUT the diagnostic tool data link test.
  2. C2 CHECK MEDIUM SPEED CAN CIRCUITS 1827 (WH/LG) AND 1828 (PK/LG) BETWEEN DLC C251 AND SJB C2280c FOR OPEN 
    • Measure the resistance between the SJB C2280c pin 9, circuit 1827 (WH/LG), harness side and the DLC C251 pin 3, circuit 1827 (WH/LG), harness side; and between the SJB C2280c pin 10, circuit 1828 (PK/LG), harness side and the DLC C251 pin 11, circuit 1828 (PK/LG), harness side.
      Fig 1: Checking Medium Speed CAN Circuits 1827 (WH/LG) And 1828 (PK/LG) Between DLC C251 And SJB C2280c For Open
      G03958567Courtesy of FORD MOTOR CO.
    • Are the resistances less than 5 ohms? 
    • Yes  : GO to  C3.
    • No  : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the self-test. CARRY OUT the diagnostic tool data link test.
  3. C3 CHECK FOR CORRECT SJB OPERATION 
    • Disconnect all the SJB connectors.
    • Check for:
      • corrosion
      • pushed-out pins
    • Connect all the SJB module 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 MULTIFUNCTION ELECTRONIC MODULES . CLEAR the DTCs. REPEAT the self-test. CARRY OUT the diagnostic tool data link test.
    • No  : The system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test. CARRY OUT the diagnostic tool data link test.