Toyota Sienna Service Manual: How to troubleshoot ecu controlled systems

Vehicle lift and support locations

1. NOTICE ABOUT VEHICLE CONDITION WHEN JACKING UP VEHICLE (a) The vehicle must be unloaded before jacking up/ lifting up the vehicle. Never jack up/lift up a heavily loaded vehicle. (b) When re ...

General information

A large number of ECU controlled systems are used in the SIENNA. In general, ECU controlled systems are considered to be very intricate, requiring a high level of technical knowledge to troubleshoo ...

Other materials:

Diagnosis system
1. DESCRIPTION  Front power seat control system data can be read through the Data Link Connector 3 (DLC3) of the vehicle. When the system seems to be malfunctioning, use the intelligent tester to check for malfunctions and perform repairs. 2. CHECK DLC3  The vehicle us ...

Removal
1. REMOVE FRONT SEAT INNER BELT ASSEMBLY HINT:  Refer to the instructions for disassembly of the front seat assembly (for flat type).  Refer to the instructions for disassembly of the front seat assembly (for manual seat). Refer to the instructions for disassembly of the fro ...

How to proceed with troubleshooting
Hint: The ecm of this system is connected to the can and multiplex communication system. Therefore, before starting troubleshooting, make sure to check that there is no trouble in the can and multiplex communication systems The intelligent tester can be used at steps 3, 4, 6, and 9. ...