Pinpoint Test Q: The Transfer Case Control Module (TCCM) Does Not Respond To The Scan Tool

Communications Network

Pinpoint Test Q: The Transfer Case Control Module (TCCM) Does Not Respond To The Scan Tool


Normal Operation

The Transfer Case Control Module (TCCM) communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

This pinpoint test is intended to diagnose the following:

- Fuse

- Wiring, terminals or connectors

- TCCM (Transfer Case Control Module)

PINPOINT TEST Q : THE TCCM (Transfer Case 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.

Q1 CHECK THE TCCM (Transfer Case Control Module) CONTROL MODULE VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

- Ignition OFF.

- Disconnect: TCCM (Transfer Case Control Module) C2371A and C2371B.

- Ignition ON.

- Measure the voltage between the TCCM (Transfer Case Control Module) C2371B-7, circuit CBB53 (GY/BN), harness side and ground.





- Measure the voltage between the TCCM (Transfer Case Control Module) C2371A-6, circuit SBB84 (GN/RD), harness side and ground; and between the TCCM (Transfer Case Control Module) C2371A-7, circuit SBB40 (VT/RD), harness side and ground.





Are the voltages greater than 10 volts?

Yes
GO to Q2.

No
VERIFY the Battery Junction Box (BJB) fuses 40 (15A), 53 (20A) and 84 (30A) 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. [1][2]Diagrams By Number

Q2 CHECK THE TCCM (Transfer Case Control Module) GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- Measure the resistance between the TCCM (Transfer Case Control Module) C2371A-3, circuit GD124 (BK/VT), harness side and ground; and between the TCCM (Transfer Case Control Module) C2371A-10, circuit GD124 (BK/VT), harness side and ground.





Are the resistances less than 5 ohms?

Yes
GO to Q3.

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

Q3 CHECK THE HS-CAN (High Speed Controller Area Network) CIRCUITS BETWEEN THE TCCM (Transfer Case Control Module) AND THE DLC (Data Link Connector) FOR AN OPEN

- Measure the resistance between the TCCM (Transfer Case Control Module) C2371B-10, circuit VDB04 (WH/BU), harness side and the DLC (Data Link Connector) C251-6, circuit VDB04 (WH/BU), harness side.





- Measure the resistance between the TCCM (Transfer Case Control Module) C2371B-9, circuit VDB05 (WH), harness side and the DLC (Data Link Connector) C251-14, circuit VDB05 (WH), harness side.





Are the resistance less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to Q4.

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

Q4 CHECK FOR CORRECT TCCM (Transfer Case Control Module) OPERATION

- Disconnect all the TCCM (Transfer Case Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect all the TCCM (Transfer Case 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 TCCM (Transfer Case 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.