Toyota Sienna Service Manual: Short in CAN Bus Lines

Toyota Sienna Service Manual / Can communication / Can communication system / Fail-safe chart / 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 Ω.

Symptom	Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is below 54 Ω.	Short in CAN bus wires ECM Network gateway ECU Skid control ECU with Actuator Steering angle sensor Yaw rate sensor Distance control ECU Junction connector CAN junction connector

WIRING DIAGRAM

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

Turn the ignition switch off before measuring the resistances of CAN bus main wires and CAN bus branch wires.
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 any 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. This communication will cause the resistance value to change.

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

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

Turn the ignition switch off.
Disconnect the ECM connector.

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

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

Standard resistance

Standard resistance

REPLACE ECM

2 CHECK FOR SHORT IN CAN BUS WIRES (NETWORK GATEWAY ECU MAIN BUS WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (NETWORK GATEWAY ECU MAIN BUS WIRE)

Disconnect the network gateway ECU connector.

CHECK FOR SHORT IN CAN BUS WIRES (NETWORK GATEWAY ECU MAIN BUS WIRE)

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

Standard resistance

Standard resistance

REPLACE NETWORK GATEWAY ECU

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

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

Disconnect the junction connector (J17).
Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

4 CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - NETWORK GATEWAY ECU MAIN BUS WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - NETWORK GATEWAY ECU MAIN BUS WIRE)

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

Standard resistance

Standard resistance

Result

Result

5 CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

CHECK FOR SHORT IN CAN BUS WIRES

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

Standard resistance

Standard resistance

REPLACE WIRING HARNESS CONNECTOR (JUNCTION CONNECTOR)

6 CHECK FOR SHORT IN CAN BUS WIRES (JUNCTION CONNECTOR - CAN JUNCTION CONNECTOR MAIN BUS WIRE)

CHECK FOR SHORT IN CAN BUS WIRES

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

Standard resistance

Standard resistance

7 CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES

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

Standard resistance

Standard resistance

8 CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)

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

Standard resistance

Standard resistance

Result

Result

REPLACE WIRING HARNESS CONNECTOR (JUNCTION CONNECTOR)

9 CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)

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

Standard resistance

Standard resistance

REPLACE WIRING HARNESS CONNECTOR (JUNCTION CONNECTOR)

10 CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR - JUNCTION CONNECTOR MAIN BUS WIRE)

CHECK FOR SHORT IN CAN BUS WIRES

Disconnect the junction connector (J49).
Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

11 CHECK FOR SHORT IN CAN BUS WIRES (CAN JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

CHECK FOR SHORT IN CAN BUS WIRES

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

Standard resistance

Standard resistance

12 CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)

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

Standard resistance

Standard resistance

REPLACE WIRING HARNESS CONNECTOR (CAN JUNCTION CONNECTOR)

13 CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)

Disconnect the skid control ECU connector.

CHECK FOR SHORT IN CAN BUS WIRES (SKID CONTROL ECU BRANCH WIRE)

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

Standard resistance

Standard resistance

REPLACE ABS & TRACTION ACTUATOR ASSEMBLY

14 CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)

Disconnect the steering angle sensor connector

CHECK FOR SHORT IN CAN BUS WIRES (STEERING ANGLE SENSOR BRANCH WIRE)

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

Standard resistance

Standard resistance

REPLACE STEERING ANGLE SENSOR

15 CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)

Disconnect the distance control ECU connector.

CHECK FOR SHORT IN CAN BUS WIRES (DISTANCE CONTROL ECU BRANCH WIRE)

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

Standard resistance

Standard resistance

REPLACE DISTANCE CONTROL ECU ASSEMBLY

16 CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)

CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)

Disconnect the yaw rate sensor connector.

CHECK FOR SHORT IN CAN BUS WIRES (YAW RATE SENSOR BRANCH WIRE)

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

Standard resistance

Standard resistance

REPLACE YAW RATE SENSOR

Open in CAN Main Bus Line

DESCRIPTION There may be an open circuit in the CAN main bus wire and/or the DLC3 branch wire when the resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 Ω or higher. ...

Short to B+ in CAN Bus Line

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