Pinpoint Test H: The Smart Junction Box (SJB) Does Not Respond to the Scan Tool

Communications Network

Pinpoint Tests

Pinpoint Test H: The Smart Junction Box (SJB) Does Not Respond To The Scan Tool

Refer to Wiring Diagram Set 10, Grounds for schematic and connector information. Diagrams By Number

Refer to Wiring Diagram Set 13, Power Distribution/SJB for schematic and connector information. Diagrams By Number

Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. Diagrams By Number

Normal Operation

The Smart Junction Box (SJB) communicates with the scan tool through the Medium Speed Controller Area Network (MS-CAN). Circuits VDB06 (GY/OG) (MS-CAN +) and VDB07 (VT/OG) (MS-CAN -) provide the network connection to the SJB. Voltage for the SJB is provided by circuit SBB19 (BU/RD). Circuit GD116 (BK/VT) provides ground.

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- SJB



PINPOINT TEST H: THE SJB DOES NOT RESPOND TO THE SCAN TOOL

NOTICE: 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 will result in false resistance readings. Refer to Battery.

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H1 CHECK THE SJB VOLTAGE SUPPLY CIRCUIT FOR AN OPEN


- Ignition OFF.
- Disconnect: SJB C2280a.
- Ignition ON.
- Measure the voltage between the SJB C2280a-4, circuit SBB19 (BU/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to H2.

No
VERIFY the Battery Junction Box (BJB) fuse 19 (40A) is OK. If OK, REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short.

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H2 CHECK THE SJB GROUND CIRCUIT FOR AN OPEN


- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Disconnect: SJB C2280d.
- Measure the resistance between the SJB C2280d-6, circuit GD116 (BK/VT), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to H3.

No
REPAIR the circuit. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.

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H3 CHECK THE MS-CAN CIRCUITS BETWEEN THE SJB AND THE DLC FOR AN OPEN


- Measure the resistance between the SJB C2280d-17, circuit VDB06 (GY/OG) , harness side and the Data Link Connector (DLC) C251-3, circuit VDB06 (GY/OG), harness side.




- 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.




- Are the resistances less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to H4.

No
REPAIR the circuit in question. CONNECT the negative battery cable. CLEAR the DTCs. REPEAT the network test with the scan tool.

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H4 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 Body Control Systems. 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.

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