Pinpoint Test J: The Smart Junction Box (SJB) Does Not Respond To The Scan Tool
WARNING: This page is about a different car, the 2008 Mercury Mariner and 2008 Ford Escape. 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.
- J1 CHECK THE SJB FUSE FOR VOLTAGE
- Key in OFF position.
- Measure the voltage between the back of the SJB fuse 5 (10A) terminals (both sides) and ground.
- Is the voltage greater than 10 volts?
- YES : Go to J2.
- NO : VERIFY the smart junction box (SJB) fuse 5 (10A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.
- J2 CHECK THE SJB GROUND CIRCUIT FOR AN OPEN
- Disconnect: SJB C2280d
- Measure the resistance between the SJB C2280d-24, circuit GD182 (BK/BU), harness side and ground; and between the SJB C2280d-12, circuit GD182 (BK/BU), harness side and ground.
- Are the resistances less than 5 ohms?
- YES : Go to J3.
- NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
- J3 CHECK THE MS-CAN CIRCUITS BETWEEN THE SJB AND THE DATA LINK CONNECTOR (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.
- 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.
- Are the resistances less than 5 ohms?
- YES : Go to J4.
- NO : REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.
- J4 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 article. 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.