Transmission Control Module Can-Bus Terminal Resistance, Checking

Transmission Control Module Can-Bus Terminal Resistance, Checking

The Engine Control Module (ECM) (J623) communicates with all databus capable control modules via a CAN databus.

These databus capable control modules are connected via two data bus wires which are twisted together (CAN_High and CAN_Low), and exchange information (messages). Missing information on the databus is recognized as a malfunction and stored.

Trouble-free operation of the CAN-bus requires that it have a terminal resistance. The central terminal resistor is located in the Engine Control Module (ECM) (J623).

Special tools, testers and auxiliary items required

• Multimeter.

• Wiring diagram.

Test requirement

• A CAN-Bus malfunction was recognized.

• The Engine Control Module (ECM) (J623) fuses OK.

• Battery voltage at least 12.5 V.

• Ignition switched off.

Procedure

- Move the passenger seat to the rear upward position.

- Release retaining tabs - A, B, and C - and remove the right passenger seat trim.





- Move the passenger seat to the front upward position.

- Disconnect the Transmission Control Module (TCM) (J217) electrical harness connector - 3 -.





• The Engine Control Module (ECM) (J623) must remain connected for the following step.

- Using a Multimeter, check the Transmission Control Module (TCM) (J217) electrical harness connector terminals 34 to 46 for resistance.

Specified value: 60 to 72 ohms (at approx. 20° C)

If the specified value was not obtained:

- Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

- Check the wiring connection for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring:

- Replace the Engine Control Module (ECM) (J623). Refer to => [ Engine Control Module, Replacing ] Engine Control Module, Replacing.

If the specified value was obtained:

Checking wiring

If the manufacturers test box is being used. Perform the following step.

- Install the test box

If the manufacturers test box is not being used. Perform the following step.

- Remove the Transmission Control Module (TCM) (J217). Refer to => [ Transmission Control Module, Replacing ] Transmission Control Module, Replacing.

- Using a Multimeter, check theTransmission Control Module (TCM) (J217) electrical harness connector to the Engine Control Module (ECM) (J623) electrical harness connector T94 for resistance.





Specified value: 1.5 ohms Max.

If the specified value was not obtained:

- Check the wiring connection for an open circuit, short circuit to Battery (+) or Ground (GND).

- Check the wiring connection for damage, corrosion, loose or broken terminals.

- If necessary, repair the faulty wiring connection.

If no malfunction is found in the wiring and the resistance was OK:

- Replace the Transmission Control Module (TCM) (J217). Refer to => [ Transmission Control Module, Replacing ] Transmission Control Module, Replacing.

- Assembly is performed in the reverse of the removal.

Final procedures

1. Check the DTC memory. => [ Diagnostic Mode 03 - Read DTC Memory ] Diagnostic Mode 03 - Read DTC Memory.

2. If necessary, erase DTC memory of the Transmission Control Module (TCM) (J217). => [ Diagnostic Mode 04 - Erase DTC Memory ] Diagnostic Mode 04 - Erase DTC Memory.

3. Generate readiness code. => [ Readiness Code ] Monitors, Trips, Drive Cycles and Readiness Codes.