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

Communications Network

Pinpoint Tests

Pinpoint Test P: 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 55, Automatic Climate Control System for schematic and connector information. Diagrams By Number

Normal Operation

The 4X4 control module communicates with the scan tool through the International Standards Organization (ISO) 9141 communications network. Circuit VDB10 (GY) provides the diagnostic connection to the Data Link Connector (DLC). Voltage for the 4X4 module is provided by circuits CBP35 (YE/GY), CBP43 (GY) and SBP40 (VT/RD). Circuit GD115 (BK/GY) provides ground.

This pinpoint test is intended to diagnose the following:

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



PINPOINT TEST P: 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.

NOTE: Failure to disconnect the battery when instructed will result in false resistance readings.

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P1 CHECK THE 4X4 CONTROL MODULE VOLTAGE SUPPLY CIRCUITS FOR AN OPEN


- Ignition OFF.
- Disconnect: 4X4 Control Module C281b.
- Ignition ON.
- Measure the voltage between the 4X4 control module, harness side and ground as follows:









- Are the voltages at each pin greater than 10 volts?

Yes
GO to P2.

No
VERIFY the Smart Junction Box (SJB) fuses 35 (10A), 40 (20A) and 43 (10A) are OK. If OK, REPAIR the circuit in question. If not OK, REFER to the Wiring Diagrams to identify the possible causes of the circuit short. CLEAR the DTCs. REPEAT the network test with the scan tool.

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P2 CHECK THE 4X4 CONTROL MODULE GROUND CIRCUIT FOR AN OPEN


- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the 4X4 control module C281b-3, GD115 (BK/GY) and ground.




- Is the resistance less than 5 ohms?

Yes
GO to P3.

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

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P3 CHECK THE ISO 9141 CIRCUIT FOR AN OPEN BETWEEN THE 4X4 CONTROL MODULE AND THE DLC


- Disconnect: 4X4 Control Module C281a.
- Measure the resistance between the 4X4 control module C281a-10, circuit VDB10 (GY), harness side and the Data Link Connector (DLC) C251-7, circuit VDB10 (GY), harness side.




- Is the resistance less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to P4.

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

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P4 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION


- Disconnect all the 4X4 control module connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the 4X4 control module 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 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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