B2326

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: B1207,B2326: Certification ECU Communication Malfunction

DTC B1207 - Certification ECU 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.

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:





C -- CHECK FOR SHORT IN CAN MS BUS WIRES (CERTIFICATION ECU)
B -- CHECK CAN MS BUS MAIN WIRE OR CONNECTOR (CERTIFICATION ECU)
A -- Continue to next step.
2. CHECK FOR SHORT TO +B IN 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:





NG -- CHECK FOR SHORT TO +B IN CAN MS BUS WIRE (CERTIFICATION ECU)
OK -- Continue to next step.
3. CHECK FOR SHORT TO GND IN 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:





NG -- CHECK FOR SHORT TO GND IN CAN MS BUS WIRE (CERTIFICATION ECU)
OK -- Continue to next step.
4. CHECK CERTIFICATION ECU (POWER SOURCE CIRCUIT)





(a) Turn the power switch off.
(b) Disconnect the E58 certification ECU connector.
(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





(d) Measure the voltage according to the value(s) in the table below.

Standard voltage:





OK -- REPLACE CERTIFICATION ECU
NG -- REPLACE HARNESS OR CONNECTOR (FUSES - ECU, ECU - BODY GROUND)
5. CHECK FOR SHORT TO +B IN CAN MS BUS WIRE (CERTIFICATION ECU)





(a) Turn the power switch off.
(b) Disconnect the E58 certification ECU connector.
(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





OK -- REPLACE CERTIFICATION ECU
NG -- Continue to next step.
6. CHECK FOR SHORT TO +B IN CAN MS BUS WIRE (CERTIFICATION ECU - MAIN BODY ECU)





(a) Turn the power switch off.
(b) Disconnect the E8 main body ECU connector.





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

HINT: The resistance must be measured after the E58 certification ECU connector is disconnected.

Standard resistance:





OK -- REPLACE MAIN BODY ECU
NG -- REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR
7. CHECK FOR SHORT TO GND IN CAN MS BUS WIRE (CERTIFICATION ECU)





(a) Turn the power switch off.
(b) Disconnect the E58 certification ECU connector.
(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





OK -- REPLACE CERTIFICATION ECU
NG -- Continue to next step.
8. CHECK FOR SHORT TO GND IN CAN MS BUS WIRE





(a) Turn the power switch off.
(b) Disconnect the E8 main body ECU connector.





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

HINT: The resistance must be measured after the E58 certification ECU connector is disconnected.

Standard resistance:





OK -- REPLACE MAIN BODY ECU
NG -- REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR
9. CHECK CAN MS BUS MAIN WIRE OR CONNECTOR (CERTIFICATION ECU)





(a) Turn the power switch off.
(b) Disconnect the E58 certification ECU connector.
(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





OK -- REPLACE CERTIFICATION ECU
NG -- Continue to next step.
10. CHECK CAN MS BUS MAIN WIRE OR CONNECTOR (CERTIFICATION ECU - MAIN BODY ECU)





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

HINT: The resistance must be measured after the E58 certification ECU connector is disconnected.

Standard resistance:





OK -- REPLACE MAIN BODY ECU
NG -- REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR
11. CHECK FOR SHORT IN CAN MS BUS WIRES (CERTIFICATION ECU)





(a) Turn the power switch off.
(b) Disconnect the E58 certification ECU connector.
(c) Measure the resistance according to the value(s) in the table below.

Standard resistance:





OK -- REPLACE CERTIFICATION ECU
NG -- Continue to next step.
12. CHECK FOR SHORT IN CAN MS BUS WIRES





(a) Turn the power switch off.
(b) Disconnect the E8 main body ECU connector.





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

HINT: The resistance must be measured after the E58 certification ECU connector is disconnected.

Standard resistance:





OK -- REPLACE MAIN BODY ECU
NG -- REPLACE CAN MS BUS MAIN WIRE OR CONNECTOR