Check CAN Bus Line

NETWORKING: CAN COMMUNICATION SYSTEM: Check CAN Bus Line; 2013 MY Corolla [07/2012 -]
- Check CAN Bus Line

DESCRIPTION

If CAN communication system DTCs 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 between main CAN bus wires and CAN Bus branch wires.
* After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
* 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 may 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.





Text in Illustration





(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:





B -- CHECK FOR OPEN IN CAN MAIN BUS LINE Open In CAN Main Bus Line

C -- CHECK CAN BUS LINES FOR SHORT CIRCUIT Check CAN Bus Lines For Short Circuit
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.





Text in Illustration





Standard Resistance:





NG -- CHECK CAN BUS LINE FOR SHORT TO +B 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.





Text in Illustration





Standard Resistance:





NG -- CHECK CAN BUS LINE FOR SHORT TO GND Check CAN Bus Line For Short to GND

OK -- GO TO HOW TO PROCEED WITH TROUBLESHOOTING How to Proceed With Troubleshooting