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Short in CAN Bus Lines








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

Short in CAN Bus Lines

DESCRIPTION

There may a short circuit in the CAN main wire and/or CAN branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ohms.






*1: w/ ABS
*2: w/ Air conditioning or PTC heater

WIRING DIAGRAM





INSPECTION PROCEDURE
NOTICE:
- Turn the ignition switch off before measuring the resistances of the CAN main wire and the CAN branch wire.
- 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 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, which causes resistance variation.

PROCEDURE

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




(a) Turn the ignition switch off.
(b) Disconnect the D41 D-CAN junction connector.




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






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO DLC3 (CAN-H, CAN-L)
OK -- Continue to next step.
2. CONNECT CONNECTOR
(a) Reconnect the D-CAN junction connector.
NEXT -- Continue to next step.
3. CHECK CAN BUS LINES FOR SHORT CIRCUIT (P-CAN J/C SIDE)




(a) Turn the ignition switch off.
(b) Disconnect the D42 P-CAN junction connector.




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






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (D-CAN J/C - P-CAN J/C)
OK -- Continue to next step.
4. CHECK CAN BUS LINES FOR SHORT CIRCUIT (P-CAN J/C - POWER STEERING ECU)




(a) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D42 P-CAN junction connector is disconnected.

Standard Resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (POWER STEERING ECU MAIN WIRE)
OK -- Continue to next step.
5. CHECK CAN BUS LINES FOR SHORT CIRCUIT (P-CAN J/C - MAIN BODY ECU)




(a) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D42 P-CAN junction connector is disconnected.

Standard Resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (MAIN BODY ECU BRANCH WIRE)
OK -- Continue to next step.
6. CHECK CAN BUS LINES FOR SHORT CIRCUIT (P-CAN J/C - COMBINATION METER ECU)




(a) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D42 P-CAN junction connector is disconnected.

Standard Resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (COMBINATION METER ECU BRANCH WIRE)
OK -- REPLACE P-CAN J/C (JUNCTION CONNECTOR)
7. CHECK CAN BUS LINES FOR SHORT CIRCUIT (D-CAN J/C - P-CAN J/C)




(a) Turn the ignition switch off.
(b) Disconnect the D41 D-CAN junction connector.
(c) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D42 P-CAN junction connector is disconnected.

Standard Resistance:






NG -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (D-CAN J/C - P-CAN J/C (CAN-H, CAN-L))
OK -- Continue to next step.
8. CONNECT CONNECTOR
(a) Reconnect the P-CAN junction connector.
NEXT -- Continue to next step.
9. CHECK CAN BUS LINES FOR SHORT CIRCUIT (D-CAN J/C - ECM)




(a) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (ECM MAIN WIRE)
OK -- Continue to next step.
10. CHECK CAN BUS LINES FOR SHORT CIRCUIT (D-CAN J/C - BRAKE ACTUATOR (SKID CONTROL ECU))
NOTE: For vehicles without ABS, go to step 11.




(a) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (BRAKE ACTUATOR (SKID CONTROL ECU) BRANCH WIRE)
OK -- Continue to next step.
11. CHECK CAN BUS LINES FOR SHORT CIRCUIT (D-CAN J/C - AIR CONDITIONING AMPLIFIER)
NOTE: For vehicles without air conditioning or PTC heater, go to step 12.




(a) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (AIR CONDITIONING AMPLIFIER BRANCH WIRE)
OK -- Continue to next step.
12. CHECK CAN BUS LINES FOR SHORT CIRCUIT (D-CAN J/C - CENTER AIRBAG SENSOR ASSEMBLY)




(a) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






NG -- CHECK CAN BUS LINES FOR SHORT CIRCUIT (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE)
OK -- REPLACE D-CAN J/C (JUNCTION CONNECTOR)
13. CHECK CAN BUS LINES FOR SHORT CIRCUIT (POWER STEERING ECU MAIN WIRE)




(a) Disconnect the D31 power steering ECU connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D42 P-CAN junction connector is disconnected.

Standard Resistance:






Result





C -- REPLACE POWER STEERING ECU
B -- REPLACE POWER STEERING ECU
A -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER STEERING ECU (P-CAN J/C - POWER STEERING ECU (CAN-H, CAN-L))
14. CHECK CAN BUS LINES FOR SHORT CIRCUIT (MAIN BODY ECU BRANCH WIRE)




(a) Disconnect the D33 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 D42 P-CAN junction connector is disconnected.

Standard Resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO MAIN BODY ECU (P-CAN J/C - MAIN BODY ECU (CAN-H, CAN-L))
OK -- REPLACE MAIN BODY ECU
15. CHECK CAN BUS LINES FOR SHORT CIRCUIT (COMBINATION METER ECU BRANCH WIRE)




(a) Disconnect the D1 combination meter ECU connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D42 P-CAN junction connector is disconnected.

Standard Resistance:






Result





C -- REPLACE COMBINATION METER ECU
B -- REPLACE COMBINATION METER ECU
A -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO COMBINATION METER ECU (P-CAN J/C - COMBINATION METER ECU (CAN-H, CAN-L))
16. CHECK CAN BUS LINES FOR SHORT CIRCUIT (ECM MAIN WIRE)




(a) Disconnect the A21 ECM connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (D-CAN J/C - ECM (CAN-H, CAN-L))
OK -- REPLACE ECM
17. CHECK CAN BUS LINES FOR SHORT CIRCUIT (BRAKE ACTUATOR (SKID CONTROL ECU) BRANCH WIRE)
(a) for Hatchback:





(1) Disconnect the A15 brake actuator (skid control ECU) connector.





(2) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:





(b) for Sedan:





(1) Disconnect the A15 brake actuator (skid control ECU) connector.





(2) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO BRAKE ACTUATOR (D-CAN J/C - BRAKE ACTUATOR (SKID CONTROL ECU) (CAN-H, CAN-L))
OK -- REPLACE BRAKE ACTUATOR ASSEMBLY (SKID CONTROL ECU)
18. CHECK CAN BUS LINES FOR SHORT CIRCUIT (AIR CONDITIONING AMPLIFIER BRANCH WIRE)




(a) Disconnect the E8 air conditioning amplifier connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO AIR CONDITIONING AMPLIFIER (D-CAN J/C - AIR CONDITIONING AMPLIFIER (CAN-H, CAN-L))
OK -- REPLACE AIR CONDITIONING AMPLIFIER
19. CHECK CAN BUS LINES FOR SHORT CIRCUIT (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE)




(a) Disconnect the D16 center airbag sensor assembly connector.




(b) Measure the resistance according to the value(s) in the table below.
HINT: The resistance must be measured after the D41 D-CAN junction connector is disconnected.

Standard Resistance:






Result





C -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
B -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
A -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO CENTER AIRBAG SENSOR ASSEMBLY (D-CAN J/C - CENTER AIRBAG SENSOR ASSEMBLY (CAN-H, CAN-L))
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