Toyota Sienna Service Manual: Electronic circuit inspection procedure

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 ...

Basic inspection

(a) WHEN MEASURING RESISTANCE OF ELECTRONIC PARTS (1) Unless otherwise stated, all resistance measurements should be made at an ambient temperature of 20°C (68°F). Resistance measurements may b ...

Other materials:

Illumination Circuit
DESCRIPTION Power is supplied to the radio and navigation assembly and steering pad switch illumination when the light control switch is in the TAIL or HEAD position. WIRING DIAGRAM INSPECTION PROCEDURE NOTICE: The vehicle is equipped with an SRS (Supplemental Restraint System) such as t ...

Brake Switch "A" Circuit
DTC P0571 Brake Switch "A" Circuit DESCRIPTION When the brake pedal is depressed, the stop light switch sends a signal to the ECM. When the ECM receives this signal, it cancels the cruise control. The fail-safe function operates to enable normal driving even if there is a malfuncti ...

Operation check
1. CHECK WINDOW LOCK SWITCH  Check that the passenger side power window and slide door power window operation is disabled when the window lock switch of the power window master switch is pressed.  Check that the passenger side power window and slide door power windows can ...