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Short to B+ in CAN Bus Line








CAN COMMUNICATION SYSTEM: Short to B+ in CAN Bus Line

Short to B+ in CAN Bus Line

DESCRIPTION

There may be a short circuit between the CAN bus line and +B when no resistance exists between terminals 6 (CANH) and 16 (BAT) or terminals 14 (CANL) and 16 (BAT) of the DLC3.





HINT:
- *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 LINE FOR SHORT TO +B (DLC3 BRANCH WIRE)





(a) Turn the ignition switch OFF.
(b) Disconnect the D41 D-CAN J/C connector.





(c) Measure the resistance.
Result:






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 J/C connector.
NEXT -- Continue to next step.
3. CHECK CAN BUS LINE FOR SHORT TO +B (P-CAN J/C SIDE)





(a) Turn the ignition switch OFF.
(b) Disconnect the D42 P-CAN J/C connector.





(c) Measure the resistance.
Result:






OK -- CHECK CAN BUS LINE FOR SHORT TO +B (P-CAN J/C - POWER STEERING ECU)
NG -- Continue to next step.
4. CONNECT CONNECTOR
(a) Reconnect the P-CAN J/C connector.
NEXT -- Continue to next step.
5. CHECK CAN BUS LINE FOR SHORT TO +B (D-CAN J/C - ECM)





(a) Disconnect the D41 D-CAN J/C connector.
(b) Measure the resistance.
Result:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B (ECM MAIN WIRE)
OK -- Continue to next step.
6. CHECK CAN BUS LINE FOR SHORT TO +B (D-CAN J/C - BRAKE ACTUATOR (SKID CONTROL ECU))
NOTE: For vehicles without ABS, go to step 7.





(a) Measure the resistance.
HINT: The resistance must be measured after the D41 D-CAN J/C connector is disconnected.

Result:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B (BRAKE ACTUATOR (SKID CONTROL ECU) BRANCH WIRE)
OK -- Continue to next step.
7. CHECK CAN BUS LINE FOR SHORT TO +B (D-CAN J/C - AIR CONDITIONING AMPLIFIER)
NOTE: For vehicles without air conditioning or PTC heater, go to step 8.





(a) Measure the resistance.
HINT: The resistance must be measured after the D41 D-CAN J/C connector is disconnected.

Result:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B (AIR CONDITIONING AMPLIFIER BRANCH WIRE)
OK -- Continue to next step.
8. CHECK CAN BUS LINE FOR SHORT TO +B (D-CAN J/C - CENTER AIRBAG SENSOR ASSEMBLY)





(a) Measure the resistance.
HINT: The resistance must be measured after the D41 D-CAN J/C connector is disconnected.

Result:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE)
OK -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (D-CAN J/C - P-CAN J/C)
9. CHECK CAN BUS LINE FOR SHORT TO +B (ECM MAIN WIRE)





(a) Disconnect the A21 ECM connector.





(b) Measure the resistance.
HINT: The resistance must be measured after the D41 D-CAN J/C connector is disconnected.

Result:






OK -- REPLACE ECM
NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO ECM (D-CAN J/C - ECM (CAN-H, CAN-L))
10. CHECK CAN BUS LINE FOR SHORT TO +B (BRAKE ACTUATOR (SKID CONTROL ECU) BRANCH WIRE)





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





(b) Measure the resistance.
HINT: The resistance must be measured after the D41 D-CAN J/C connector is disconnected.

Result:






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





(a) Disconnect the E8 air conditioning amplifier connector.





(b) Measure the resistance.
HINT: The resistance must be measured after the D41 D-CAN J/C connector is disconnected.

Result:






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





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





(b) Measure the resistance.
HINT: The resistance must be measured after the D41 D-CAN J/C connector is disconnected.

Result:






OK -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY
NG -- REPLACE CAN BRANCH WIRE CONNECTED TO CENTER AIRBAG SENSOR ASSEMBLY (D-CAN J/C - CENTER AIRBAG SENSOR ASSEMBLY (CAN-H, CAN-L))
13. CHECK CAN BUS LINE FOR SHORT TO +B (P-CAN J/C - POWER STEERING ECU)





(a) Measure the resistance.
HINT: The resistance must be measured after the D42 P-CAN J/C connector is disconnected.

Result:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B (POWER STEERING ECU MAIN WIRE)
OK -- Continue to next step.
14. CHECK CAN BUS LINE FOR SHORT TO +B (P-CAN J/C - MAIN BODY ECU)





(a) Measure the resistance.
HINT: The resistance must be measured after the D42 P-CAN J/C connector is disconnected.

Result:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B (MAIN BODY ECU BRANCH WIRE)
OK -- Continue to next step.
15. CHECK CAN BUS LINE FOR SHORT TO +B (P-CAN J/C - COMBINATION METER ECU)





(a) Measure the resistance.
HINT: The resistance must be measured after the D42 P-CAN J/C connector is disconnected.

Result:






NG -- CHECK CAN BUS LINE FOR SHORT TO +B (COMBINATION METER ECU BRANCH WIRE)
OK -- REPAIR OR REPLACE CAN MAIN WIRE OR CONNECTOR (D-CAN J/C - P-CAN J/C (CAN-H, CAN-L))
16. CHECK CAN BUS LINE FOR SHORT TO +B (POWER STEERING ECU MAIN WIRE)





(a) Disconnect the D31 power steering ECU connector.





(b) Measure the resistance.
HINT: The resistance must be measured after the D42 P-CAN J/C connector is disconnected.

Result:






OK -- REPLACE POWER STEERING ECU
NG -- REPAIR OR REPLACE CAN MAIN WIRE CONNECTED TO POWER STEERING ECU (P-CAN J/C - POWER STEERING ECU (CAN-H, CAN-L))
17. CHECK CAN BUS LINE FOR SHORT TO +B (MAIN BODY ECU BRANCH WIRE)





(a) Disconnect the D33 main body ECU connector.





(b) Measure the resistance.
HINT: The resistance must be measured after the D42 P-CAN J/C connector is disconnected.

Result:






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





(a) Disconnect the D1 combination meter ECU connector.





(b) Measure the resistance.
HINT: The resistance must be measured after the D42 P-CAN J/C connector is disconnected.

Result:






OK -- REPLACE COMBINATION METER ECU
NG -- REPAIR OR REPLACE CAN BRANCH WIRE CONNECTED TO COMBINATION METER (P-CAN J/C - COMBINATION METER ECU (CAN-H, CAN-L))
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