B2326

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: B2326: CAN MS Bus Line Communication Malfunction

DTC B2326 - CAN MS Bus Line Communication Malfunction

DESCRIPTION

The main body ECU and certification ECU perform 2-way communication with each other via the Controller Area Network (CAN). If the certification ECU cannot communicate with the main body ECU, the main body ECU will conclude that there is a malfunction in the CAN system, and set a DTC.






WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- Turn the power switch off before measuring the resistances of CAN bus main wires and CAN bus branch wires.
- After the power switch is turned off, check that the key reminder warning system and lighting system are not operating.
- Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the power switch, any other switches, or the doors. If any doors need to be opened in order to check connectors, open the doors and leave them open.
HINT:
- Operating the power switch, any other switches, or a door triggers related ECU and sensor communication on the CAN. This communication will cause 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 MS BUS WIRE




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






Result:






B -- CHECK FOR SHORT IN CAN BUS WIRES (No. 4 CAN JUNCTION CONNECTOR)
A -- Continue to next step.
2. CHECK FOR CAN BUS MAIN WIRE (CERTIFICATION ECU)
(a) Turn the power switch off.




(b) Disconnect the certification ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Turn the power switch off.
Standard resistance:






NG -- CHECK FOR CAN BUS MAIN WIRE (No. 4 CAN JUNCTION CONNECTOR)
OK -- REPLACE CERTIFICATION ECU
3. CHECK FOR CAN BUS MAIN WIRE (No. 4 CAN JUNCTION CONNECTOR)
(a) Reconnect the certification ECU connector.
(b) Disconnect the No. 4 CAN junction connector.




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






Result:






C -- REPLACE HARNESS OR CONNECTOR (No. 4 CAN JUNCTION CONNECTOR - CERTIFICATION ECU)
B -- CHECK CERTIFICATION ECU (MAIN BODY ECU)
A -- REPLACE JUNCTION CONNECTOR
4. CHECK CERTIFICATION ECU (MAIN BODY ECU)
(a) Reconnect the No. 4 CAN junction connector.




(b) Disconnect the E8 main body ECU connector.
(c) Measure the resistance according to the value(s) in the table below.
Turn the power switch off.
Standard resistance:






NG -- REPLACE HARNESS OR CONNECTOR (No. 4 CAN JUNCTION CONNECTOR - MAIN BODY ECU)
OK -- REPLACE MAIN BODY ECU
5. CHECK FOR SHORT IN CAN BUS WIRES (No. 4 CAN JUNCTION CONNECTOR)
(a) Turn the power switch off.
(b) Disconnect the No.4 CAN junction connector.




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






Result:






C -- CHECK FOR SHORT IN CAN BUS WIRES (TIRE PRESSURE WARNING ECU)
B -- CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)
A -- Continue to next step.
6. CHECK FOR SHORT IN CAN BUS WIRES (CERTIFICATION ECU)
(a) Disconnect the certification ECU connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the certification ECU connector is disconnected.

Standard resistance:






NG -- REPLACE HARNESS OR CONNECTOR (No. 4 CAN JUNCTION CONNECTOR - CERTIFICATION ECU)
OK -- REPLACE CERTIFICATION ECU
7. CHECK FOR SHORT IN CAN BUS WIRES (MAIN BODY ECU)
(a) Disconnect the main body ECU connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the main body ECU connector is disconnected.

Standard resistance:






NG -- REPLACE HARNESS OR CONNECTOR (No. 4 CAN JUNCTION CONNECTOR - MAIN BODY ECU)
OK -- REPLACE MAIN BODY ECU
8. CHECK FOR SHORT IN CAN BUS WIRES (TIRE PRESSURE WARNING ECU)
(a) Disconnect the tire pressure warning ECU connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the tire pressure warning ECU connector is disconnected.

Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (No. 4 CAN JUNCTION CONNECTOR - TIRE PRESSURE WARNING ECU)
OK -- REPLACE TIRE PRESSURE MONITOR ECU (TIRE PRESSURE WARNING ECU)