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 communicaton is one of the vehicle communications method, which is now widely used to transfer signals.
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 malfuncting and sets this code.
Item | Detecting Condition | Possible Cause |
DTC Strategy | ● Signal check, high and low | ● Open in signal circuit ● Short to ground in signal circuit ● Faulty TCM ● Faulty ECM |
Enable Conditions | ● Ignition on | |
Threshold Value | ● CAN bus error. | |
Diagnostic Time | ● 1 sec. | |
MIL Fuel Limit Fuel Cut EGR Off | ● No ● No ● No ● No |
Connect scantool to data link connector(DLC).
Engine "ON".
Monitor the "CAN COMMUNICATION SERVICE DATA (ENGINE RPM, VEHICLE SPEED SENSOR, THROTTLE P. SENSOR)" parameters on the scantool.
Compare it with referance data as below.
Does "CAN BUS LINE DATA " follow the referance data?
▶ Fault is intermittent caused by poor contact in the sensor's and/or PCM/TCM's connector or was repaired and PCM/TCM memory was not cleared.And go to Verification of Vehicle Repair procedure.
▶ Replace PCM/TCM and then go to "Verification of Vehicle Repair" procedure.
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.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Go to "Signal Circuit Inspection" procedure.
Check for open in harness
Ignition "OFF" & Engine "OFF".
Disconnect ECM & TCM connector.
Measure resistance between terminal 4 of TCM harness connector and terminal 9 of ECM harness connector.
Measure resistance between terminal 3 of TCM harness connector and terminal 10 of ECM harness connector.
Specification : Approx. below 1Ω
Is the measured resistance within specifications ?
▶ Go to "Check for short to ground in harness" as below.
▶ Check for open in the signal harness.
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check for short to ground in harness.
Ignition "OFF" & Engine "OFF".
Disconnect TCM,ECM, TCCU and HCU connector.
Measure resistance between terminal 4 of TCM harness connector and chassis ground.
Measure resistance between terminal 3 of TCM harness connector and chassis ground.
Specification : Infinite
Is the measured resistance within specificaitons ?
▶ Go to "Component Inspection" procedure.
▶ Check for short to ground in signal harness.
Repair as necessary and go to "Verification of Vehicle Repair" procedure.
Check resistance
Ignition "OFF" & Engine "OFF".
Disconnect TCM connector.
Measure resistance between terminal 3 and 4 of TCM harness connector.
Not TCS,4WD equipped | TCS, 4WD equipped | ||
ECM & TCM connected | ECM connected only | TCM connected only | ECM & TCM connected |
60Ω ± 1Ω | 120Ω ± 2Ω | 120Ω ± 2Ω | 120Ω ± 2Ω |
Is the measured resistance within specifications ?
▶ Go to "Check signal waveform" as below.
▶ Substitute with a known-good ECM and check for proper operation.
If the problem is corrected, replace ECM and then go to "Verification of Vehicle Repair" procedure.
Check signal waveform
Ignition "OFF" & Engine "OFF".
Disconnect ECM connector.
Monitor signal waveform at terminal 3 and 4 of TCM connector simultaneously.
Are CAN signals generated correctly ?
▶ Thoroughly check connectors for looseness, poor connection,bending, corrosion, contamination, deterioration, or damage. Repair or replace as necessary and then go to "Verification of Vehicle Repair" procedure.
▶ Substitute with a known-good ECM and check for proper operation.
If the problem is corrected, replace ECM and then go to "Verification of Vehicle Repair" procedure.
After a repair, it is essential to verify that the fault has been corrected.
Connect scan tool and select "Diagnostic Trouble Codes(DTCs)" mode and then clear DTC.
Operate the vehicle within DTC Enable conditions in General information.
Are any DTCs present ?
Go to the applicable troubleshooting procedure.
System is performing to specification at this time.
