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:

Problem symptoms table
ENTIRE SYSTEM METER GAUGES WARNING LIGHTS INDICATOR LIGHTS BUZZER ACCESSORY METER ASSEMBLY ...

Diagnosis system
1. CHECK DLC3  The vehicle uses ISO 15765-4 communication protocol. The terminal arrangement of the DLC3 complies with SAE 1962 and matched the ISO 15765-4 format. If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connecto ...

Brake Switch "B" Circuit High
DESCRIPTION The purpose of this circuit is to prevent the engine from stalling while driving in lock-up condition when brakes are suddenly applied. When the brake pedal is depressed, this switch sends a signals to the ECM. Then the ECM cancels the operation of the lock-up clutch while ...