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Open in One Side of CAN Branch Line





NETWORKING: CAN COMMUNICATION SYSTEM: Open in One Side of CAN Branch Line
- Open in One Side of CAN Branch Line

DESCRIPTION

If some ECUs and sensors are not displayed on the "Communication Bus Check" screen of the Techstream and some ECUs and sensors repeatedly appear and disappear on the screen when the CAN main bus wires are normal (there is no open, short, short to +B or short to GND in the main bus wires), there may be an open circuit in either of the CAN branch wires.

HINT
If some ECUs and sensors repeatedly appear and disappear on the "Communication Bus Check" screen, communication between the normal ECUs and sensors and the Techstream may be affected by the incomplete signals that are output from the ECU that has an open circuit in either of its CAN branch wires. In this case, the CAN branch wires for the ECUs and sensors that repeatedly appear and disappear from the screen are normal and the ECU that is not displayed on the screen may be the main cause of the problem (this ECU may have an open circuit in either of its CAN branch wires).





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.
* Perform the following inspection for the ECUs (sensors) which are not displayed on the Techstream. If a malfunction cannot be identified, perform the following inspections for the ECUs (sensors) connected to the CAN communication system.
* Do not remove the combination meter assembly (combination meter ECU) and ECM, as they are the end parts of the circuit. If removed, CAN communication will not be possible.
* The open circuit confirmation of the combination meter assembly (combination meter ECU), ECM and main wire is performed in the CHECK CAN BUS LINE procedure of How to Proceed with Troubleshooting. This inspection only has procedures for checking for an open circuit on one side of the CAN branch wire.

PROCEDURE

1. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SKID CONTROL ECU)

(a) Disconnect the A16 brake actuator assembly (skid control ECU) connector.

(b) Select "Communication Bus Check" on the Techstream Diagnosis System.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU)
A -- Continue to next step.

2. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (SKID CONTROL ECU BRANCH WIRE)

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





HINT
The resistance must be measured after the A16 brake actuator assembly (skid control ECU) connector is disconnected.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

3. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU)

(a) Disconnect the D42 main body ECU connector.

(b) Select "Communication Bus Check" on the Techstream Diagnosis System.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (STEERING SENSOR)
A -- Continue to next step.

4. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (MAIN BODY ECU BRANCH WIRE)

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





HINT
The resistance must be measured after the D42 main body ECU connector is disconnected.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK -- REPLACE MAIN BODY ECU Removal

5. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (STEERING SENSOR)

(a) Disconnect the D20 spiral cable sub-assembly (steering sensor) connector.

(b) Select "Communication Bus Check" on the Techstream Diagnosis System.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR ASSEMBLY)
A -- Continue to next step.

6. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (STEERING SENSOR BRANCH WIRE)

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





HINT
The resistance must be measured after the D20 spiral cable sub-assembly (steering sensor) connector is disconnected.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK -- REPLACE SPIRAL CABLE SUB-ASSEMBLY Removal

7. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR ASSEMBLY)

(a) Disconnect the D43 center airbag sensor assembly connector.

(b) Select "Communication Bus Check" on the Techstream Diagnosis System.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (YAW RATE SENSOR)
A -- Continue to next step.

8. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (CENTER AIRBAG SENSOR ASSEMBLY BRANCH WIRE)

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





HINT
The resistance must be measured after the D43 center airbag sensor assembly connector is disconnected.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK -- REPLACE CENTER AIRBAG SENSOR ASSEMBLY Removal

9. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (YAW RATE SENSOR)

(a) Disconnect the D58 yaw rate sensor connector.

(b) Select "Communication Bus Check" on the Techstream Diagnosis System.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY)
A -- Continue to next step.

10. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (YAW RATE SENSOR BRANCH WIRE)

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





HINT
The resistance must be measured after the D58 yaw rate sensor connector is disconnected.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK -- REPLACE YAW RATE SENSOR Removal

11. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY)

(a) Disconnect the D16 air conditioning amplifier assembly connector.

(b) Select "Communication Bus Check" on the Techstream Diagnosis System.

Result





B -- CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU BRANCH WIRE)
A -- Continue to next step.

12. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (AIR CONDITIONING AMPLIFIER ASSEMBLY BRANCH WIRE)

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





HINT
The resistance must be measured after the D16 air conditioning amplifier assembly connector is disconnected.

Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK -- REPLACE AIR CONDITIONING AMPLIFIER ASSEMBLY Removal

13. CHECK FOR OPEN IN ONE SIDE OF CAN BRANCH WIRE (POWER STEERING ECU BRANCH WIRE)

(a) Disconnect the D51 steering column assembly (power steering ECU) connector.

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





Standard Resistance:





Text in Illustration





NG -- REPAIR OR REPLACE CAN BRANCH WIRE OR CONNECTOR (CAN-H, CAN-L)

OK -- REPLACE STEERING COLUMN ASSEMBLY Removal
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