Pinpoint Test D: The 4X4 Control Module Does Not Respond To The Scan Tool

Communications Network

Pinpoint Tests

Pinpoint Test D: The 4X4 Control Module Does Not Respond To The Scan Tool

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

Refer to Wiring Diagram Set 34, All Wheel Drive (AWD) for schematic and connector information. Diagrams By Number

Normal Operation

The 4X4 control module communicates with the scan tool through the High Speed Controller Area Network (HS-CAN). Circuits VDB04 (WH/BU) (HS-CAN +) and VDB05 (WH) (HS-CAN -) provide the network connection to the 4X4 control module. The 4X4 control module shares the HS-CAN with the PCM, the Accessory Protocol Interface Module (APIM), the Steering Effort Control Module (SECM), the ABS module, the Restraints Control Module (RCM), Occupant Classification System Module (OCSM) and the Instrument Cluster (IC). Voltage for the 4X4 control module is provided by circuit CBP34 (VT/BN) and SBP11 (BU/RD). Ground is provided by circuit GD148 (BK/YE).

This pinpoint test is intended to diagnose the following:

- Fuse
- Wiring, terminals or connectors
- 4X4 control module



PINPOINT TEST D: THE 4X4 CONTROL MODULE 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.

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D1 CHECK THE VOLTAGE SUPPLY CIRCUIT FOR AN OPEN


- Ignition OFF.
- Disconnect: 4X4 Control Module C281.
- Ignition ON.
- Measure the voltage between the 4X4 control module C281-4, circuit CBP34 (VT/BN), harness side and ground, and between the 4X4 control module C281-5, circuit SBP11 (BU/RD), harness side and ground.




- Is the voltage greater than 10 volts?

Yes
GO to D2.

No
VERIFY the Smart Junction Box (SJB) fuses 34 (5A) and 11 (10A) are OK. If OK, REPAIR the circuit. If not OK, Refer to the Wiring Diagrams to identify the possible causes of the short circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.

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D2 CHECK THE GROUND CIRCUIT FOR AN OPEN


- Ignition OFF.
- Measure the resistance between the 4X4 control module C281-15, circuit GD148 (BK/YE), harness side and ground.




- Is the resistance less than 5 ohms?

Yes
GO to D3.

No
REPAIR the circuit. CLEAR the DTCs. REPEAT the network test with the scan tool.

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D3 CHECK THE HS-CAN CIRCUITS BETWEEN THE 4X4 CONTROL MODULE AND THE DATA LINK CONNECTOR (DLC) FOR AN OPEN


- Measure the resistance between the 4X4 control module C281-3, circuit VDB04 (WH/BU), harness side and the DLC C251-6, circuit VDB04 (WH/BU), harness side.




- Measure the resistance between the 4X4 control module C281-11, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.




- Are the resistances less than 5 ohms?

Yes
GO to D4.

No
REPAIR the circuit in question. CLEAR the DTCs. REPEAT the network test with the scan tool.

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D4 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION


- Disconnect the 4X4 control module connector.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect the 4X4 control module connector and make sure it seats correctly.
- Operate the system and verify the concern is still present.
- Is the concern still present?

Yes
INSTALL a new 4X4 control module. 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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