Short in CAN Bus Lines

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

Short in CAN Bus Lines

DESCRIPTION

There may be a short circuit between the CAN bus lines when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ohms.





HINT: *: w/ dynamic radar cruise control system.

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
Turn the power switch OFF before measuring the resistances of the main wire and the branch wire.
HINT: Operating the power switch, any switches or any doors triggers related ECU and sensor communication with the CAN, which causes resistance variation.

PROCEDURE

1. CHECK CAN BUS LINES FOR SHORT CIRCUIT (DLC3 BRANCH WIRE)




(a) Disconnect the K86 CAN junction connector center connector.
(b) Measure the resistance of the DLC3.

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CANH, CANL)
OK -- Continue to next step.
2. CONNECT CONNECTOR
(a) Reconnect the K86 CAN junction connector center connector.
NEXT -- Continue to next step.
3. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR RR SIDE)




(a) Disconnect the V37 CAN junction connector RR connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR RR - SEAT BELT CONTROL ECU)
NG -- Continue to next step.
4. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR CENTER - CAN JUNCTION CONNECTOR RR)




(a) Disconnect the K87 CAN junction connector center connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (CAN JUNCTION CONNECTOR CENTER - CAN JUNCTION CONNECTOR RR)
NG -- Continue to next step.
5. CONNECT CONNECTOR
(a) Reconnect the K87 CAN junction connector center connector.
(b) Reconnect the V37 CAN junction connector RR connector.
NEXT -- Continue to next step.
6. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR CENTER - NETWORK GATEWAY ECU)




(a) Disconnect the K84 CAN junction connector center connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (NETWORK GATEWAY ECU)
NG -- Continue to next step.
7. CONNECT CONNECTOR
(a) Reconnect the K84 CAN junction connector center connector.
NEXT -- Continue to next step.
8. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR CENTER - CLEARANCE WARNING ECU)




(a) Disconnect the K88 CAN junction connector center connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (CLEARANCE WARNING ECU)
NG -- Continue to next step.
9. CONNECT CONNECTOR
(a) Reconnect the K88 CAN junction connector center connector.
NEXT -- Continue to next step.
10. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR CENTER - DISTANCE CONTROL ECU)
NOTICE:
For vehicles without dynamic radar cruise control system, go to "CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR CENTER - HYBRID VEHICLE CONTROL ECU)".




(a) Disconnect the K85 CAN junction connector center connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (DISTANCE CONTROL ECU)
NG -- Continue to next step.
11. CONNECT CONNECTOR
(a) Reconnect the K85 CAN junction connector center connector.
NEXT -- Continue to next step.
12. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR CENTER - HYBRID VEHICLE CONTROL ECU)




(a) Disconnect the K83 CAN junction connector center connector.
(b) Measure the resistance of the DLC3.
Standard resistance:






OK -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (HYBRID VEHICLE CONTROL ECU)
NG -- REPAIR OR REPLACE CAN JUNCTION CONNECTOR CENTER
13. CHECK CAN BUS LINES FOR SHORT CIRCUIT (NETWORK GATEWAY ECU)




(a) Disconnect the K66 network gateway ECU connector.
(b) Measure the resistance of the wire harness side connector.

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO NETWORK GATEWAY ECU (CANH, CANL)
OK -- REPLACE NETWORK GATEWAY ECU
14. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CLEARANCE WARNING ECU)




(a) Disconnect the A38 clearance warning ECU connector.
(b) Measure the resistance of the wire harness side connector.

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO CLEARANCE WARNING ECU (CANH, CANL)
OK -- REPLACE CLEARANCE WARNING ECU
15. CHECK CAN BUS LINES FOR SHORT CIRCUIT (DISTANCE CONTROL ECU)




(a) Disconnect the K13 distance control ECU connector.
(b) Measure the resistance of the wire harness side connector.

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DISTANCE CONTROL ECU (CANH, CANL)
OK -- REPLACE DISTANCE CONTROL ECU
16. CHECK CAN BUS LINES FOR SHORT CIRCUIT (HYBRID VEHICLE CONTROL ECU)




(a) Disconnect the A54 hybrid vehicle control ECU connector.
(b) Measure the resistance of the wire harness side connector.

Result





NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO HYBRID VEHICLE CONTROL ECU (CANH, CANL)
OK -- REPLACE HYBRID VEHICLE CONTROL ECU
17. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR RR - SEAT BELT CONTROL ECU)




(a) Disconnect the V38 CAN junction connector RR connector.
(b) Measure the resistance of the wire harness side connector.

Result





A -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (SEAT BELT CONTROL ECU)
B -- Continue to next step.
18. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CAN JUNCTION CONNECTOR RR - ECM)




(a) Disconnect the V37 CAN junction connector RR connector.
(b) Measure the resistance of the wire harness side connector.
Standard resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (ECM)
OK -- REPAIR OR REPLACE CAN JUNCTION CONNECTOR RR
19. CHECK CAN BUS LINES FOR SHORT CIRCUIT (SEAT BELT CONTROL ECU)




(a) Disconnect the V43 seat belt control ECU connector.
(b) Measure the resistance of the wire harness side connector.

Result





NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO SEAT BELT CONTROL ECU (CANH, CANL)
OK -- REPLACE SEAT BELT CONTROL ECU
20. CHECK CAN BUS LINES FOR SHORT CIRCUIT (ECM)
(a) Disconnect the A53 ECM connector.




(b) Measure the resistance of the wire harness side connector.






NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (CANH, CANL)
OK -- REPLACE ECM