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

Refer to Wiring Diagram Set 14, Module Communications Network for schematic and connector information. [1][2]Diagrams By Number

Refer to Wiring Diagram Set 29, Transmission Controls for schematic and connector information. [1][2]Diagrams By Number

Normal Operation

The Transmission Control Module (TCM) is present on hybrid vehicles only. The TCM (Transmission Control Module) communicates with the scan tool through the High Speed Controller Area Network (HS-CAN).

NOTE: Only vehicles with a 3.5L gasoline engine or 2.5L hybrid engine are equipped with a TCM (Transmission Control Module). The PCM controls the transmission on 2.5L gasoline and 3.0L gasoline engine vehicles.

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

- Ignition OFF.

- Disconnect: TCM (Transmission Control Module) C1458A (2.5L Hybrid).

- Disconnect: TCM (Transmission Control Module) C1533 (3.5L).

- Ignition ON.

- For 3.5L, measure the voltage between the TCM (Transmission Control Module) C1533-1, circuit SBB16 (VT/RD), harness side and ground; and between the TCM (Transmission Control Module) C1533-11, circuit CBP44 (VT), harness side and ground.

- For 2.5L hybrid, measure the voltage between the TCM (Transmission Control Module) , harness side and ground as follows:

Connector-Pin Circuit C1458A-4 CBB39 (VT/WH) C1458A-5 CBB39 (VT/WH) C1458A-12 SBB23 (RD)

Are the voltages greater than 10 volts?

Yes
GO to G2.

No
For 3.5L gasoline, VERIFY the Battery Junction Box (BJB) fuse 16 (15A) or Smart Junction Box (SJB) fuse 44 (10A) is OK. For 2.5L hybrid, VERIFY the BJB (Battery Junction Box) fuse 23 (10A) or fuse 39 (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. [1][2]Diagrams By Number

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

- Ignition OFF.

- Disconnect: Negative Battery Cable.

- For 3.5L gasoline, measure the resistance between the TCM (Transmission Control Module) C1533-9, circuit GD120 (BK/GN), harness side and ground.

- For 2.5L hybrid measure the resistance between the TCM (Transmission Control Module) C1458A-2, circuit GD121 (BK/YE), harness side and ground; and between the TCM (Transmission Control Module) C1458A-8, circuit GD121 (BK/YE), harness side and ground.

Are the resistances less than 5 ohms?

Yes
For 3.5L engine, GO to G3.

For 2.5L hybrid engine, GO to G4.

No
REPAIR the circuit in question. CONNECT the negative battery cable. 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 - 3.5L ENGINE

- Measure the resistance between the TCM (Transmission Control Module) C1533-14, 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 TCM (Transmission Control Module) C1533-6, circuit VDB05 (WH), harness side and the DLC (Data Link Connector) C251-14, circuit VDB05 (WH), harness side.

- Measure the resistance between the TCM (Transmission Control Module) C1458A-7, 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 G5.

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

G5 CHECK FOR CORRECT TCM (Transmission Control Module) OPERATION

- Disconnect all the TCM (Transmission Control Module) connectors.

- Check for:
- corrosion

- damaged pins

- pushed-out pins

- Connect all the TCM (Transmission 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 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. CLEAR the DTCs. REPEAT the network test with the scan tool.