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

WARNING: This page is about a different car, the 2006 Mercury Milan, 2006 Lincoln Zephyr, and 2006 Ford Fusion. 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.

G1 CHECK THE SJB C2280D FOR DAMAGE
- Key in OFF position.
- Disconnect: SJB C2280d.
- Inspect the SJB C2280d for damage.
- Is the SJB C2280d OK?
Yes : GO to G2.

No : REPAIR the SJB C2280d as necessary. CONNECT the SJB C2280d. CARRY OUT the data link diagnostics test.
G2 CHECK THE MEDIUM SPEED CAN CIRCUITS BETWEEN THE DLC AND THE SJB FOR AN OPEN
- Measure the resistance between the SJB C2280d-17, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
  
  Fig 1: Checking Medium Speed CAN Circuits Between DLC And SJB For Open (1 Of 2)
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the SJB C2280d-1, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
  
  Fig 2: Checking Medium Speed CAN Circuits Between DLC And SJB For Open (2 Of 2)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
Yes : GO to G3.

No : REPAIR the circuit. CONNECT the SJB C2280d. CARRY OUT the data link diagnostics test.
G3 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - Corrosion
  - Pushed-out pins
- Connect all the SJB 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 CONTROL MODULES . CLEAR the diagnostic trouble codes (DTCs). REPEAT the self-test. CARRY OUT the data link diagnostics test.

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. CARRY OUT the data link diagnostics test.