Toyota Sienna Service Manual: Diagnosis Circuit

Toyota Sienna Service Manual / Supplemental restraint system / Airbag system / Diagnostic trouble code chart / Diagnosis Circuit

DESCRIPTION

DTC output mode is set by connecting terminals TC and CG of the DLC3.

DTCs are displayed by blinking the SRS warning light.

HINT:

When each warning light stays blinking, a ground short in the wiring of terminal TC of the DLC3 or an internal ground short in each ECU is suspected.
A DTC output mode signal is transmitted through BEAN and CAN to each ECU including the center airbag sensor assembly. Thus when all systems do not enter DTC output mode, there may be an ECM malfunction

WIRING DIAGRAM

WIRING DIAGRAM

INSPECTION PROCEDURE

1 CHECK MULTIPLEX COMMUNICATION SYSTEM

Check if the multiplex communication system DTC is output.

HINT: The center airbag sensor assembly of this system is connected to the multiplex communication system.

Therefore, before starting troubleshooting, make sure to check that there is no trouble in the multiplex communication system.

OK: The Multiplex communication system DTC is not output.

REPAIR CIRCUITS INDICATED BY OUTPUT DTCS

2 CHECK CAN COMMUNICATION SYSTEM

Use the intelligent tester to check if the CAN communication system is functioning normally.

HINT: The ECM is connected to the CAN communication system. Therefore, before starting troubleshooting, make sure to check that there is no trouble in the CAN communication system.

OK: The CAN communication system is functioning normally.

REPAIR CAN COMMUNICATION CIRCUIT

3 CHECK WIRE HARNESS (TC OF DLC3 - TC OF ECM)

CHECK WIRE HARNESS (TC OF DLC3 - TC OF ECM)

Turn the ignition switch to the LOCK position.
Disconnect the connector from the ECM.
Measure the resistance according to the value(s) in the table below.

Standard resistance

Standard resistance

REPAIR OR REPLACE WIRE HARNESS (TC OF DLC3 - TC OF ECM)

4 CHECK WIRE HARNESS (CG OF DLC3 - BODY GROUND)

CHECK WIRE HARNESS (CG OF DLC3 - BODY GROUND)

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

Standard resistance

Standard resistance

REPAIR OR REPLACE WIRE HARNESS (CG OF DLC3 - BODY GROUND)

5 CHECK WIRE HARNESS (TC OF DLC3 - BODY GROUND)

CHECK WIRE HARNESS (TC OF DLC3 - BODY GROUND)

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

Standard resistance

Standard resistance

REPAIR OR REPLACE WIRE HARNESS OR EACH ECU

REPLACE CENTER AIRBAG SENSOR ASSEMBLY

SRS Warning Light does not Come ON

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Occupant classification system

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