Toyota Sienna Service Manual: Short to B+ in CAN Bus Line

Toyota Sienna Service Manual / Can communication / Can communication system / Fail-safe chart / Short to B+ in CAN Bus Line

DESCRIPTION

A short to B+ is suspected in the CAN bus wire when the resistance between terminals 6 (CANH) and 16 (BAT), or terminals 14 (CANL) and 16 (BAT) of the DLC3 is below 6 kΩ.

Symptom	Trouble Area
The resistance between terminals 6 (CANH) and 16 (BAT), or terminals 14 (CANL) and 16 (BAT) of the DLC3 is below 6 kΩ.	Short to B+ in CAN bus wire 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 TO B+ IN CAN BUS WIRE (ECM MAIN BUS WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (ECM MAIN BUS WIRE)

Turn the ignition switch off.
Disconnect the ECM connector .

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (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 TO B+ IN CAN BUS WIRE (NETWORK GATEWAY MAIN BUS WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NETWORK GATEWAY MAIN BUS WIRE)

Disconnect the Network gateway ECU connector .

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (NETWORK GATEWAY 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 TO B+ IN CAN BUS WIRE (DLC3 BRANCH WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (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 TO B+ IN CAN BUS WIRE (JUNCTION CONNECTOR - NETWORK GATEWAY MAIN BUS WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (JUNCTION CONNECTOR - NETWORK GATEWAY 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 TO B+ IN CAN BUS WIRE (JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

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 TO B+ IN CAN BUS WIRE (JUNCTION CONNECTOR - CAN JUNCTION CONNECTOR MAIN BUS WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (JUNCTION CONNECTOR - CAN JUNCTION CONNECTOR MAIN BUS WIRE)

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

Standard resistance

Standard resistance

7 CHECK FOR SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU BRANCH WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU BRANCH WIRE)

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

Standard resistance

Standard resistance

8 CHECK FOR SHORT TO B+ IN CAN BUS WIRE (STEERING ANGLE SENSOR BRANCH WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (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 TO B+ IN CAN BUS WIRE (DISTANCE CONTROL ECU BRANCH WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (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 TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - JUNCTION CONNECTOR MAIN BUS WIRE)

Disconnect the junction connector (J49).

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - JUNCTION CONNECTOR MAIN BUS WIRE)

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

Standard resistance

Standard resistance

11 CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (CAN JUNCTION CONNECTOR - ECM MAIN BUS WIRE)

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

Standard resistance

Standard resistance

12 CHECK FOR SHORT TO B+ IN CAN BUS WIRE (YAW RATE SENSOR BRANCH WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (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 TO B+ IN CAN BUS WIRE (SKID CONTROL ECU BRANCH WIRE)

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (SKID CONTROL ECU BRANCH WIRE)

Disconnect the skid control ECU connector.

CHECK FOR SHORT TO B+ IN CAN BUS WIRE (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 CHECK FOR TO B+ IN BUS WIRE (STEERING ANGLE SENSOR BRANCH WIRE)

CHECK CHECK FOR TO B+ IN BUS WIRE (STEERING ANGLE SENSOR BRANCH WIRE)

Disconnect the steering angle sensor connector

CHECK CHECK FOR TO B+ IN BUS WIRE (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 CHECK FOR TO B+ IN BUS WIRE (DISTANCE CONTROL ECU BRANCH WIRE)

CHECK CHECK FOR TO B+ IN BUS WIRE (DISTANCE CONTROL ECU BRANCH WIRE)

Disconnect the distance control ECU connector.

CHECK CHECK FOR TO B+ IN BUS WIRE (DISTANCE CONTROL ECU BRANCH WIRE)

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

Standard resistance

Standard resistance

16 CHECK CHECK FOR TO B+ IN BUS WIRE (YAW RATE SENSOR BRANCH WIRE)

CHECK CHECK FOR TO B+ IN BUS WIRE (YAW RATE SENSOR BRANCH WIRE)

Disconnect the yaw rate sensor connector

CHECK CHECK FOR TO B+ IN BUS WIRE (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

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