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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

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 resistance of the CAN main wire and CAN branch wires.
* After the ignition switch is turned off, check that the key reminder warning system and light reminder warning system are not operating.
* 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 other switches or any triggers related ECU and sensor communication on the CAN, which would cause resistance reading variations.

PROCEDURE

1. CHECK FOR SHORT IN CAN BUS WIRES (DLC3 BRANCH WIRE)

(a) Turn the ignition switch off.





(b) Disconnect the DLC3 branch wire gray connector (E62) from the No. 1 CAN J/C "B" side (without earth terminal).

HINT
E62 connector color: Gray

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





Standard resistance:





(d) Reconnect the DLC3 branch wire connector (E62) to the No. 1 CAN J/C "B" side (without earth terminal).

NG -- REPAIR OR REPLACE DLC3 BRANCH WIRE OR CONNECTOR
OK -- Continue to next step.

2. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 CAN J/C SIDE)

(a) Disconnect the CAN main bus wire white connector (E42) from the No. 1 CAN J/C "A" side (with earth terminal).





HINT
E42 connector color: White

(b) Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.





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

Standard resistance:





OK -- CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN - NO. 1 CAN J/C)
NG -- Continue to next step.

3. CHECK FOR SHORT IN CAN BUS WIRES (NO. 1 CAN J/C BRANCH WIRE)

(a) Reconnect the CAN main bus wire connector (E42) to the No. 1 CAN J/C "A" side (with earth terminal).





(b) Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.

(c) While observing the resistance value shown on the tester, disconnect connectors E44, E45, E46 and E63 from the No. 1 CAN J/C one by one until the resistance becomes normal (between 54 and 69 Ohms).

HINT
Disconnect the branch wire connectors other than those of the DLC3.

















NOTICE:
Do not reconnect the disconnected connectors until this inspection is complete because there may be a short in 2 or more branch wires.

Result:





(d) When there is a short in one or more of the branch wires:

(1) Reconnect all of the connectors to the No. 1 CAN J/C, except for the one that was disconnected last (the short-circuited bus wire). Check that the resistance shown on the tester is normal (between 54 and 69 Ohms) to confirm that there is a short in one branch wire only.

HINT
* The connectors connected to the No. 1 CAN J/C can be distinguished according to the color of the communication bus wires and the shape of the connectors.
* Reconnecting the connectors to non-specified positions on the No. 1 CAN J/C does not affect system operation. However, it is preferred to reconnect the connectors to their specified positions to avoid negative effects on the wiring such as tension on the wiring harnesses, and to make future maintenance easier.

B -- RECONNECT CONNECTOR
A -- Continue to next step.

4. CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER MAIN BUS WIRE)

(a) Disconnect the combination meter main bus wire white connector (E43) from the No. 1 CAN J/C "B" side (without earth terminal).





HINT
E43 connector color: White

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





Standard resistance:





NG -- REPLACE NO. 1 CAN J/C
OK -- Continue to next step.

5. RECONNECT CONNECTOR

(a) Reconnect the combination meter main bus wire connector (E43) to the No. 1 CAN J/C "B" side (without earth terminal).

NEXT -- Continue to next step.

6. CHECK FOR SHORT IN CAN BUS WIRES (COMBINATION METER)

(a) Disconnect the combination meter connector (F1).





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

Standard resistance:





HINT
If the resistance changes to 108 to 132 Ohms when the connector is disconnected, there may be a short in the Combination meter.

NG -- REPAIR OR REPLACE CAN BUS MAIN WIRE (COMBINATION METER MAIN BUS WIRE)

OK -- REPLACE COMBINATION METER

7. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN - NO. 1 CAN J/C)

(a) Reconnect the No. 1 CAN J/C connector (E42).

(b) Disconnect the No. 2 CAN J/C connector (E41).





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

Standard resistance:





NG -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (NO. 1 CAN J/C - NO. 2 CAN J/C)
OK -- Continue to next step.

8. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN J/C)

(a) Reconnect the No. 2 CAN J/C connector (E41) (front of the vehicle).





(b) Disconnect the No. 2 CAN J/C connector (A40) (rear of the vehicle).

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





Standard resistance:





OK -- CHECK FOR SHORT IN CAN BUS WIRES (ECM MAIN BUS WIRE)
NG -- Continue to next step.

9. CHECK FOR SHORT IN CAN BUS WIRES (A/C AMPLIFIER BRANCH WIRE)

(a) Reconnect the No. 2 CAN J/C connector (A40) (rear of the vehicle).

(b) Disconnect the air conditioning amplifier connector.

(c) Disconnect the No. 2 CAN J/C connector (E41) (front of the vehicle).





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

Standard resistance:





NG -- REPAIR OR REPLACE A/C AMPLIFIER BRANCH WIRE OR CONNECTOR
OK -- Continue to next step.

10. CHECK FOR SHORT IN CAN BUS WIRES (ACCESSORY GATEWAY BRANCH WIRE)

(a) Disconnect the accessory option (w/ accessory option).

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





Standard resistance:





NG -- REPAIR OR REPLACE ACCESSORY GATEWAY BRANCH WIRE OR CONNECTOR
OK -- Continue to next step.

11. CHECK FOR SHORT IN CAN BUS WIRES (NAVIGATION ECU BRANCH WIRE)

(a) Disconnect the navigation receiver connector (w/ accessory option).





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





Standard resistance:





NG -- REPAIR OR REPLACE RADIO AND NAVIGATION ASSEMBLY BRANCH WIRE OR CONNECTOR
OK -- Continue to next step.

12. CHECK FOR SHORT IN CAN BUS WIRES (NO. 2 CAN J/C)

(a) Reconnect the No. 2 CAN J/C connector (E41).

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





NOTICE:
The resistance must be measured after the main wire connected ECU and junction connector are reconnected.

Standard resistance:





NG -- REPLACE NO. 2 CAN J/C
OK -- Continue to next step.

13. CHECK FOR SHORT IN CAN BUS WIRES (ECU)

Connect the probes of an ohmmeter to terminals 6 (CANH) and 14 (CANL) of the DLC3.





(a) While observing the resistance value shown on the tester, reconnect the each ECU connector until the resistance becomes abnormal (Below 54 Ohms).

(b) Replace the ECU that caused the total resistance to drop below 54 Ohms when it was reconnected.

HINT
If the resistance becomes abnormal when an ECU connector is reconnected, there may be a short in the ECU.

NEXT -- REPLACE CORRESPONDING ECU OR SENSOR

14. CHECK FOR SHORT IN CAN BUS WIRES (ECM MAIN BUS WIRE)

(a) Disconnect the No. 2 CAN J/C connector (A40).





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

Standard resistance:





NG -- CHECK FOR SHORT IN CAN BUS WIRES (ECM MAIN BUS WIRE)
OK -- Continue to next step.

15. CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU - NO. 2 CAN J/C)

(a) Disconnect the skid control ECU connector (A26 or A60).

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





Standard resistance:





HINT
Measure the resistance with the No. 2 CAN J/C connector (A40) disconnected.

NG -- REPAIR OR REPLACE SKID CONTROL ECU BRANCH WIRE OR CONNECTOR

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY

16. CHECK FOR SHORT IN CAN BUS WIRES (ECM MAIN BUS WIRE)

(a) Disconnect the ECM connector (A24 or A55).





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

Standard resistance:





HINT
Measure the resistance with the No. 2 CAN J/C connector (A40) disconnected.

NG -- REPAIR OR REPLACE CAN BUS MAIN WIRE OR CONNECTOR (ECM - NO. 2 CAN J/C)

OK -- REPLACE ECM

17. RECONNECT CONNECTOR

(a) Reconnect the connector for the short-circuited branch wire to the No. 1 CAN J/C (the connector that caused the bus wire resistance to become normal (between 54 and 69 Ohms) when it was disconnected).

NEXT -- Continue to next step.

18. CHECK FOR SHORT IN CAN BUS WIRES

(a) Disconnect the connector that includes terminals CANH and CANL from the ECU (or sensor) to which the short-circuited branch wire is connected. Symptom Related Diagnostic Procedures





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

Standard resistance:





HINT
If the resistance becomes normal (between 54 and 69 Ohms) when the connector is disconnected from the ECU (or sensor), there may be a short in the ECU (or sensor).

NG -- REPAIR OR REPLACE CORRESPONDING ECU OR SENSOR BRANCH WIRE OR CONNECTOR

OK -- REPLACE CORRESPONDING ECU OR SENSOR
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