Short in CAN Bus Lines

CAN COMMUNICATION: CAN COMMUNICATION SYSTEM: Short in CAN Bus Lines

Short in CAN Bus Lines

DESCRIPTION

The CAN bus wires are considered to be shorted when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ohms.

WIRING DIAGRAM

INSPECTION PROCEDURE
NOTICE:
- Turn the ignition switch off before measuring the resistances of CAN bus main 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 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 connectors, open the doors and leave them open.
HINT: Operating the ignition switch, any switches, or any doors triggers related ECU and sensor communication with the CAN. This communication will cause the resistance value to change.

PROCEDURE

1. CHECK FOR SHORT IN CAN BUS WIRES (ECM MAIN BUS WIRE)
(a) Turn the ignition switch off.

(b) Disconnect the ECM connector.

NG -- CHECK FOR SHORT IN CAN BUS WIRES (NETWORK GATEWAY ECU MAIN BUS WIRE)
OK -- REPLACE ECM
2. CHECK FOR SHORT IN CAN BUS WIRES (NETWORK GATEWAY ECU MAIN BUS WIRE)

(a) Disconnect the network gateway ECU connector.

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

NG -- CHECK FOR SHORT IN CAN BUS WIRES (DLC3 BRANCH WIRE)
OK -- REPLACE NETWORK GATEWAY ECU
3. CHECK FOR SHORT IN CAN BUS WIRES (DLC3 BRANCH WIRE)
(a) Disconnect the junction connector (J17).

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

NG -- REPAIR OR REPLACE DLC3 BRANCH WIRE OR CONNECTOR
OK -- Continue to next step.
4. CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - NETWORK GATEWAY ECU MAIN BUS WIRE)

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

Result:

C -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (JUNCTION CONNECTOR - NETWORK GATEWAY ECU)
B -- CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - CAN JUNCTION CONNECTOR MAIN BUS WIRE)
A -- Continue to next step.
5. CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

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

NG -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (JUNCTION CONNECTOR - ECM)
OK -- REPLACE WIRING HARNESS CONNECTOR (JUNCTION CONNECTOR)
6. CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - CAN JUNCTION CONNECTOR MAIN BUS WIRE)

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

NG -- CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR - JUNCTION CONNECTOR MAIN BUS WIRE)
OK -- Continue to next step.
7. CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)

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

NG -- CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)
OK -- Continue to next step.
8. CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)

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

Result:

C -- CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)
B -- CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)
A -- REPLACE WIRING HARNESS CONNECTOR (JUNCTION CONNECTOR)
9. CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)

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

NG -- CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)
OK -- REPLACE WIRING HARNESS CONNECTOR (JUNCTION CONNECTOR)
10. CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR - JUNCTION CONNECTOR MAIN BUS WIRE)
(a) Disconnect the junction connector (J49).

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

NG -- REPAIR OR REPLACE CAN BUS MAIN WIRE (JUNCTION CONNECTOR - CAN JUNCTION CONNECTOR)
OK -- Continue to next step.
11. CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

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

NG -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (CAN JUNCTION CONNECTOR - ECM)
OK -- Continue to next step.
12. CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)

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

NG -- CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)
OK -- REPLACE WIRING HARNESS CONNECTOR (CAN JUNCTION CONNECTOR)
13. CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)

(a) Disconnect the skid control ECU connector.

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

NG -- REPAIR OR REPLACE SKID CONTROL ECU BRANCH WIRE OR CONNECTOR
OK -- REPLACE ABS & TRACTION ACTUATOR ASSEMBLY
14. CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)

(a) Disconnect the steering angle sensor connector.

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

NG -- REPAIR OR REPLACE STEERING ANGLE SENSOR BRANCH WIRE OR CONNECTOR
OK -- REPLACE STEERING ANGLE SENSOR
15. CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)

(a) Disconnect the distance control ECU connector.

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

NG -- REPAIR OR REPLACE DISTANCE CONTROL ECU BRANCH WIRE OR CONNECTOR
OK -- REPLACE DISTANCE CONTROL ECU ASSEMBLY
16. CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)

(a) Disconnect the yaw rate sensor connector.

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

NG -- REPAIR OR REPLACE YAW RATE SENSOR BRANCH WIRE OR CONNECTOR
OK -- REPLACE YAW RATE SENSOR