Pinpoint Test F: The SJB Does Not Respond To The Scan Tool

WARNING: This page is about a different car, the 2013 Ford Mustang. However, it is still accessible from the selected car via links, so may be relevant.

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

NOTE: Failure to disconnect the battery when instructed results in false resistance readings. Refer to BATTERY, MOUNTING AND CABLES .

F1 CHECK THE SJB VOLTAGE SUPPLY CIRCUIT FOR AN OPEN
- Ignition ON.
- NOTE: Measurements are taken with the fuses installed.
  
  Measure the voltage between the SJB fuse 5 (10A) and ground.
  
  Fig 1: Measuring Voltage Between Back Of SJB Fuse 5 (10A) Terminals And Ground
  Courtesy of FORD MOTOR CO.
- Is the voltage greater than 10 volts?
- Yes : GO to F2.
- No : VERIFY the SJB fuse 5 (10A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool. If not OK, REFER to the SYSTEM WIRING DIAGRAMS to identify the possible causes of the circuit short.
F2 CHECK THE SJB GROUND CIRCUIT FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect: SJB C2280D.
- Measure the resistance between the SJB C2280D-8, circuit GD139 (BK/YE), harness side and ground; and between the SJB C2280D-12, circuit GD139 (BK/YE), harness side and ground.
  
  Fig 2: Measuring Resistance Between SJB C2280D-8, Circuit GD139 (BK/YE) And Ground
  Courtesy of FORD MOTOR CO.
- Is the resistance less than 5 ohms?
- Yes : GO to F3.
- No : REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
F3 CHECK THE MS-CAN CIRCUITS BETWEEN THE SJB AND THE DLC FOR AN OPEN
- Disconnect: SJB C2280B.
- Measure the resistance between the SJB C2280B-37, circuit VDB06 (GY/OG), harness side and the DLC C251-3, circuit VDB06 (GY/OG), harness side.
  
  Fig 3: Measuring Resistance Between SJB C2280B-37, Circuit VDB06 (GY/OG) And DLC C251-3
  Courtesy of FORD MOTOR CO.
- Measure the resistance between the SJB C2280B-38, circuit VDB07 (VT/OG), harness side and the DLC C251-11, circuit VDB07 (VT/OG), harness side.
  
  Fig 4: Measuring Resistance Between SJB C2280B-38, Circuit VDB07 (VT/OG) And DLC C251-11, Circuit VDB07 (VT/OG)
  Courtesy of FORD MOTOR CO.
- Are the resistances less than 5 ohms?
- Yes : CONNECT the negative battery cable. GO to F4.
- No : REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.
F4 CHECK FOR CORRECT SJB OPERATION
- Disconnect all the SJB connectors.
- Check for:
  - corrosion
  - damaged pins
  - 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 MODULES . CLEAR the DTCs. REPEAT the network test with the scan tool.
- 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 network test with the scan tool.