INTRODUCTION – HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
IN–39
IN
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:
3.
SYMPTOM CONFIRMATION AND DIAGNOSTIC
TROUBLE CODE
HINT:
The diagnostic system in the FJ CRUISER 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 malfunction in the signal circuits
to the ECU occurs. In a DTC check, a previous
malfunction's DTC can be checked by a technician
during troubleshooting.
•
Another function is the Input Signal Check, which
checks if the signals from various switches are sent to
the ECU correctly.
By using these functions, the problem areas can be
narrowed down and troubleshooting is more effective.
Diagnostic functions are incorporated in the following
system in the FJ CRUISER.
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
System
DTC Check
(Normal Mode)
DTC Check
(Check Mode)
Freeze-frame
Data
Sensor Check
/ Test Mode
(Input Signal
Check)
Data List
Active Test
Customize
Parameter
1GR-FE SFI
SYSTEM
{
{
{
-
{
{
-
A750E
AUTOMATIC
TRANSAXLE
SYSTEM
{
{
-
-
{
{
-
A750F
AUTOMATIC
TRANSAXLE
SYSTEM
{
{
-
-
{
{
-
VEHICLE
STABILITY
CONTROL
SYSTEM
{
-
{
{
{
{
-
AIRBAG
SYSTEM
{
{
-
-
{
-
-