Check CAN Bus Line

NETWORKING: CAN COMMUNICATION SYSTEM: Check CAN Bus Line

Check CAN Bus Line

DESCRIPTION

If any DTCs from the CAN communication system are not output, first measure the resistance between the terminals of the DLC3 to specify the trouble area, and check that there is no short in the CAN wire, and +B or GND.

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- Turn the ignition switch off before measuring the resistance of the main CAN bus wires and the CAN Bus branch wire.
- After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not in operation.
- Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the ignition switch, any other switches or the doors. If any doors need to be opened in order to check the connectors, open the doors and leave them open.
HINT:
- Operating the ignition switch, any other switches, or a door triggers related ECU and sensor communication on the CAN. This communication will cause the resistance value to change.
- Even after DTCs are cleared, if a DTC is stored again after driving the vehicle for a while, the malfunction may be occurring due to vibration of the vehicle. In such a case, wiggling the ECUs or wire harness while performing the inspection below will help determine the cause of the malfunction.

PROCEDURE

1. CHECK CAN BUS WIRE (MAIN WIRE FOR DISCONNECTION, CAN BUS LINES FOR SHORT CIRCUIT)




(a) Turn the ignition switch off.
(b) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






C -- CHECK CAN BUS LINES FOR SHORT CIRCUIT
B -- CHECK FOR OPEN IN CAN MAIN BUS LINE
A -- Continue to next step.
2. CHECK FOR SHORT TO B+ IN CAN BUS WIRE




(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B
OK -- Continue to next step.
3. CHECK FOR SHORT TO GND IN CAN BUS WIRE




(a) Measure the resistance according to the value(s) in the table below.
Standard Resistance:






NG -- CHECK CAN BUS LINE FOR SHORT TO GND
OK -- GO TO HOW TO PROCEED WITH TROUBLESHOOTING