Toyota Sienna Service Manual: Customer problem analysis

Toyota Sienna Service Manual / Introduction / How to troubleshoot ecu controlled systems / How to proceed with troubleshooting / Customer problem analysis

HINT:

In troubleshooting, confirm that the problem symptoms have been accurately identified. Preconceptions should be discarded in order to make an accurate judgment. To clearly understand what the problem symptoms are, it is extremely important to ask the customer about the problem and the conditions at the time the malfunction occurred.
Gather as much information as possible for reference.
Past problems that seem unrelated may also help in some cases.
The following 5 items are important points in the problem analysis:

What	Vehicle model, system name
When	Date, time, occurrence frequency
Where	Road conditions
Under what conditions?	Running conditions, driving conditions, weather conditions
How did it happen?	Problem symptoms

Operation flow

HINT: Perform troubleshooting in accordance with the procedures below. The following is an outline of basic troubleshooting procedures. Confirm the troubleshooting procedures for the circuit you a ...

Symptom confirmation and diagnostic trouble code

HINT: The diagnostic system in the SIENNA has various functions. The first function is the Diagnostic Trouble Code (DTC) check. A DTC is a code stored in the ECU memory whenever a malfunctio ...

Other materials:

Evap monitor (key-off type)
(a) Preconditions The monitor will not run unless: The fuel tank is less than 90% full. The altitude is less than 8000 ft (2450 m). The vehicle is stationary. The engine coolant temperature is between 4.4°C and 35°C (40°F and 95°F). The intake air temperature is between 4.4°C and ...

Evaporative Emission Control System Leak Detected
DTC P0455 Evaporative Emission Control System Leak Detected (Gross Leak) DTC P0456 Evaporative Emission Control System Leak Detected (Very Small Leak) DTC SUMMARY DESCRIPTION The circuit description can be found in the EVAP (Evaporative Emission) System. INSPECTION PROCEDURE Refer to t ...

Navigation check mode
HINT: This mode displays GPS satellite information. Illustrations may differ from the actual vehicle depending on the device settings and options. Therefore, some detailed areas may not be shown exactly the same as on the actual vehicle. 1. ENTER DIAGNOSTIC MODE ( ) 2. NA ...