Automatic Transmission System

Component Location






General Description

The TCM can either receive data from the Engine Control Module or ABS control module, or it can send data to the ECM and ABSCM by using CAN communication. The CAN communication is one of the vehicle communications method, which is now widely used to transfer the vehicle data.

DTC Description

The TCM reads data on the CAN-BUS line and checks whether the data is equal to the data which the TCM sent before. If the data is not the same the TCM decides that either the CAN-BUS line or TCM are malfunctioning and sets this code.

DTC Detecting Condition






Diagnostic Circuit Diagram






Signal Waveform & Data






Fig 1) "CAN Communication"

Monitor GDS Data

1. Connect GDS to data link connector(DLC)
2. Engine "ON".
3. Monitor the "CAN COMMUNICATION SERVICE DATA (ENGINE RPM, VEHICLE SPEED SENSOR, THROTTLE P. SENSOR)" parameters on the GDS.










Fig 1) Low-speed
Fig 2) High-speed
4. Does "CAN BUS LINE DATA " follow the referance data?






Terminal & Connector Inspection

1. Many malfunctions in the electrical system are caused by poor harness and terminals. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
2. Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
3. Has a problem been found?






Signal Circuit Inspection

1. Ignition "OFF".
2. Disconnect "ECU" connector.
3. Measure resistance between CAN high terminal and CAN low terminal of PCM/TCM harness connector.

Specification :Approx. 120 Ohms ± 10Ohms

4. Is the measured resistance within specifications ?






Verification of Vehicle Repair

After a repair, it is essential to verify that the fault has been corrected.
1. Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode.
2. Using a GDS, Clear DTC.
3. Operate the vehicle within DTC Enable conditions in General information.
4. Are any DTCs present ?