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:

Data list
HINT: Reading the DATA LIST displayed on an intelligent tester enables values, including those of the switches, sensors, and actuators, to be checked without removing any parts. Reading the DATA LIST as the first step in troubleshooting is one method to shorten diagnostic time. NOTICE: ...

System description
1. CRUISE CONTROL SYSTEM This system is controlled by the ECM, and is activated by the throttle position sensor and motor. The ECM controls the following functions: ON-OFF, - (COAST)/SET, + (ACCEL)/RES (RESUME), CANCEL, vehicle speed operation, motor output control, and overdrive control. & ...

How to proceed with troubleshooting
HINT:  Use this procedure to troubleshoot the engine immobiliser system.  The intelligent tester should be used in steps 4, 5 and 7. 1 VEHICLE BROUGHT TO WORKSHOP 2 CUSTOMER PROBLEM ANALYSIS CHECK AND SYMPTOM CHECK 3 CRANK ENGINE FOR MORE THAN 10 SECONDS 4 CHECK FOR DTC C ...