Pinpoint Test G: The Transmission Control Module (TCM) Does Not Respond To The Scan Tool

Communications Network

Pinpoint Test G: The Transmission Control Module (TCM) Does Not Respond To The Scan Tool


Normal Operation

The Transmission Control Module (TCM) is used on automatic transmission-equipped diesel engine vehicles only. The TCM (Transmission Control Module) 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

- TCM (Transmission Control Module)

PINPOINT TEST G : THE TCM (Transmission 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.

G1 CHECK THE TCM (Transmission Control Module) VOLTAGE SUPPLY CIRCUITS FOR AN OPEN

- Disconnect: TCM (Transmission Control Module) C1750.

- Ignition ON.

- Measure the voltage between the TCM (Transmission Control Module), harness side and ground as follows:

Connector-Pin Circuit C1750-1 SBB46 (BN/RD) C1750-31 SBB46 (BN/RD) C1750-33 CBB52 (GN/WH)






Are the voltages greater than 10 volts?

Yes
GO to G2.

No
VERIFY the Battery Junction Box (BJB) fuses 46 (10A) and 52 (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. [1][2]Diagrams By Number

G2 CHECK THE TCM (Transmission Control Module) GROUND CIRCUIT FOR AN OPEN

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- Measure the resistance between the TCM (Transmission Control Module), harness side and ground as follows:

Connector-Pin Circuit C1750-9 GD177 (BU/GY) C1750-39 GD177 (BU/GY) C1750-41 GD120 (BK/GN)






Are the resistances less than 5 ohms?

Yes
GO to G3.

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

G3 CHECK THE HS-CAN (High Speed Controller Area Network) CIRCUITS BETWEEN THE TCM (Transmission Control Module) AND THE DLC (Data Link Connector) FOR AN OPEN

- Measure the resistance between the TCM (Transmission Control Module) C1750-47, circuit VDB04 (WH/BU), harness side and the Data Link Connector (DLC) C251-6, circuit VDB04 (WH/BU), harness side.





- Measure the resistance between the TCM (Transmission Control Module) C1750-48, circuit VDB05 (WH), harness side and the DLC (Data Link Connector) C251-14, circuit VDB05 (WH), harness side.





Are the resistances less than 5 ohms?

Yes
CONNECT the negative battery cable. GO to G4.

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

G4 CHECK FOR CORRECT TCM (Transmission Control Module) OPERATION

- Disconnect the TCM (Transmission Control Module) connector.

- Check for:
- corrosion

- damaged pins

- pushed-out pins


- Connect the TCM (Transmission 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 TCM (Transmission 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.