Toyota Sienna Service Manual: Open in CAN Main Bus Line

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

Symptom	Trouble Area
Resistance between terminals 6 (CANH) and 14 (CANL) of the DLC3 is 69 Ω or higher.	CAN main bus wire or connector Junction connector CAN junction connector DLC3 branch wire or connector Network gateway ECU ECM

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 DLC3

CHECK DLC3

Turn the ignition switch off.
Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

Result

Result

NOTICE: When the measured value is 133 Ω or more and a CAN communication system diagnostic trouble code is output, there may be a fault besides disconnection of the DLC3 branch wire. For that reason, troubleshooting should be performed again from "HOW TO PROCEED WITH TROUBLESHOOTING" (See page CA-7 ) after repairing the trouble area.

2 CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM CAN MAIN BUS WIRE)

Turn the ignition switch off.

CHECK FOR OPEN IN CAN BUS MAIN WIRE (ECM CAN MAIN BUS WIRE)

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

Standard resistance

Standard resistance

REPLACE ECM

3 CHECK FOR OPEN IN CAN BUS MAIN WIRE (NETWORK GATEWAY ECU CAN MAIN BUS WIRE)

CHECK FOR OPEN IN CAN BUS MAIN WIRE

Reconnect the ECM connector.
Disconnect the network gateway ECU connector.
Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

REPLACE NETWORK GATEWAY ECU

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

Reconnect the network gateway ECU connector.
Disconnect the junction connector (J17).

CHECK FOR OPEN IN CAN BUS MAIN WIRE

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

Standard resistance

Standard resistance

Result

Result

5 CHECK CHECK FOR OPEN IN CANBUS MAIN WIRE (JUNCTION CONNECTOR - ECM)

CHECK CHECK FOR OPEN IN CANBUS MAIN WIRE (JUNCTION CONNECTOR - ECM)

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 OPEN IN CAN BUS MAIN WIRE (JUNCTION CONNECTOR -Å@CAN JUNCTION CONNECTOR)

CHECK FOR OPEN IN CAN BUS MAIN WIRE

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

Standard resistance

Standard resistance

REPLACE WIRING HARNESS CONNECTOR (JUNCTION CONNECTOR)

7 CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN JUNCTION CONNECTOR - JUNCTION CONNECTOR)

CHECK FOR OPEN IN CAN BUS MAIN WIRE

Reconnect the junction connector (J17).
Disconnect the CAN junction connector (J49).
Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

8 CHECK FOR OPEN IN CAN BUS MAIN WIRE (CAN JUNCTION CONNECTOR - ECM)

CHECK FOR OPEN IN CAN BUS MAIN WIRE

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

Standard resistance

Standard resistance

REPLACE WIRING HARNESS CONNECTOR (CAN JUNCTION CONNECTOR)

CAN Bus Line

DESCRIPTION When any DTC for the CAN communication system is output, first measure the resistance between the terminals of the DLC3 to specify the trouble area, and check that there is no short ...

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 ...

Other materials:

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1. CHECK DLC3 The vehicle's ECU uses ISO 15765-4 for communication protocol. The terminal arrangement of the DLC3 complies with SAE J1962 and matches the ISO 15765-4 format. NOTICE: *: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do ...

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