LAN System: Symptom When Error Occurs in CAN Communication System

LAN System: Symptom When Error Occurs in CAN Communication System

In CAN communication system, multiple units mutually transmit and receive signals. Each unit cannot transmit and receive signals if any error occurs on CAN communication line. Under this condition, multiple control units related to the root cause malfunction or go into fail-safe mode.

ERROR EXAMPLE

NOTE:
- Each vehicle differs in symptom of each unit under fail-safe mode and CAN communication line wiring.
- Refer to [How to Use This Section] for the unit abbreviation.

Example: TCM branch line open circuit






Example: Data link connector branch line open circuit






NOTE:
- When data link connector branch line is open, transmission and reception of CAN communication signals are not affected. Therefore, no symptoms occur. However, be sure to repair malfunctioning circuit.
- When data link connector branch line is open, "ECU list" displayed on the SDT "Bus check" may be the same as when the CAN communication line has short-circuit. However, symptoms differ depending on the case. See below chart for the differences.






Example: Main Line Between Data Link Connector and ABS Actuator and Electric Unit (Control Unit) Open Circuit






Example: CAN-H, CAN-L Harness Short Circuit