Pinpoint Test E: The 4X4 Control Module Does Not Respond To The Scan Tool
Communications Network
Pinpoint Tests
Pinpoint Test E: 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, Four Wheel Drive Systems 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. Voltage is supplied by circuits CBP18 (GY/OG), SBB23 (RD/WH) and SBB26 (RD/BK). Ground is supplied by circuits GD138 (BK/WH) and GD145 (BK/BU).
This pinpoint test is intended to diagnose the following:
- Fuse
- Wiring, terminals or connectors
- 4X4 control module
PINPOINT TEST E: 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. Refer to Battery.
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E1 CHECK THE 4X4 CONTROL MODULE VOLTAGE SUPPLY CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: 4X4 Control Module C281a.
- Disconnect: 4X4 Control Module C281b.
- Ignition ON.
- Measure the voltage between the 4X4 control module, harness side and ground as follows:
- Are the voltages greater than 10 volts?
Yes
GO to E2.
No
VERIFY the Battery Junction Box (BJB) fuse 23 (20A) or fuse 26 (20A) is OK and the Smart Junction Box (SJB) fuse 18 (10A) is 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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E2 CHECK THE 4X4 CONTROL MODULE GROUND CIRCUITS FOR AN OPEN
- Ignition OFF.
- Disconnect: Negative Battery Cable.
- Measure the resistance between the 4X4 control module, harness side and ground as follows:
- Are the resistances less than 5 ohms?
Yes
GO to E3.
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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E3 CHECK THE HS-CAN CIRCUITS BETWEEN THE 4X4 CONTROL MODULE AND THE DLC FOR AN OPEN
- Measure the resistance between the 4X4 control module C281a-10, 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 C281a-9, circuit VDB05 (WH), harness side and the DLC C251-14, circuit VDB05 (WH), harness side.
- Are the resistances less than 5 ohms?
Yes
CONNECT the negative battery cable. GO to E4.
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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E4 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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