CAN

CAN COMMUNICATION CIRCUIT

Diagnosis Procedure


1. CONNECTOR INSPECTION

1.Turn the power switch OFF.
2.Disconnect the 12V battery cable from the negative terminal. Refer to "Precaution for Removing 12V Battery" Precaution For Removing 12V Battery.
3.Disconnect all the control unit connectors on CAN communication circuit.
4.Check terminals and connectors for damage, bend and loose connection.
Is the inspection result normal?
YES- GO TO 2.
NO- Repair the terminal and connector.

2. CHECK HARNESS CONTINUITY (SHORT CIRCUIT)

Check the continuity between the data link connector terminals.





Is the inspection result normal?
YES- GO TO 3.
NO- Check the harness and repair the root cause.

3. CHECK HARNESS CONTINUITY (SHORT CIRCUIT)

Check the continuity between the data link connector and the ground.





Is the inspection result normal?
YES- GO TO 4.
NO- Check the harness and repair the root cause.

4. CHECK VCM AND BCM TERMINATION CIRCUIT

1.Remove the VCM and the BCM.
2.Check the resistance between the VCM terminals.





3.Check the resistance between the BCM terminals.





Is the measurement value within the specification?
YES- GO TO 5.
NO- Replace the VCM and/or the BCM.

5. CHECK SYMPTOM

Connect all the connectors. Check if the symptoms described in the "Symptom (Results from interview with customer)" are reproduced.
Inspection result
Reproduced-GO TO 6.
Non-reproduced-Start the diagnosis again. Follow the trouble diagnosis procedure when past error is detected.

6. CHECK CONTROL UNIT REPRODUCTION

Perform the reproduction test as per the following procedure for each control unit.
1.Turn the power switch OFF.
2.Disconnect the 12V battery cable from the negative terminal. Refer to "Precaution for Removing 12V Battery" Precaution For Removing 12V Battery.
3.Disconnect one of the control unit connectors of CAN communication circuit.
NOTE:
VCM and BCM have a termination circuit. Check other control units first.
4.Connect the 12V battery cable to the negative terminal. Check if the symptoms described in the "Symptom (Results from interview with customer)" are reproduced.
NOTE:
Although control unit-related error symptoms occur, do not confuse them with other symptoms.
Inspection result
Reproduced-Connect the connector. Check other control units as per the above procedure.
Non-reproduced-Replace the control unit whose connector was disconnected.