Toyota 4A-FE Repair Manual

EFI SYSTEM - Diagnosis System
F12546
DIAGNOSIS SYSTEM
DESCRIPTION
The ECU contains a built-in self-diagnosis system by
which troubles with the engine signal network are
detected and a "CHECK ENGINE" warning light on the
instrument panel flashes.
By analyzing various signals
as shown in the later table
(See pages Fl-28 to 31) the ECU detects system malfunc-
tions which are related to the various operating parameter
sensors or actuator. The ECU stores the failure code
associated with the detected failure until the diagnosis
system is cleared by removing the fuse stop 15A (AE) or
EFI 15A (AT) with the ignition switch OFF.
The "CHECK ENGINE" Warning light on the instrument
panel informs the driver that a malfunction has been
detected.
The light goes out automatically when the malfunction
has been cleared.
CHECK ENGINE WARNING LIGHT CHECK
1. The "CHECK ENGINE" warning light will come on when
the ignition switch is placed at ON and the engine is not
running.
2. When the engine is started, the "CHECK ENGINE" warning
light should go out.
If the light remains on. the diagnosis system has detected
a malfunction or abnormality in the system.
OUTPUT OF DIAGNOSTIC CODES
To obtain an output of diagnostic codes, proceed as follow:
1. Initial conditions
(a) Battery voltage 11 V or more
(b) Throttle valve fully closed (throttle position sensor
IDL points closed)
(c) Transmission in neutral position
(d) Accessories switched OFF
2. Turn the ignition switch to ON. Do not start the engine.
3. Using SST, connect terminals TE1 and E1 of the check
connector.
SST SST 09843-18020
LOCATION: See page Fl-1 33
Fl7502

Toyota 4A-FE Specifications

General

Brand	Toyota
Model	4A-FE
Category	Engine
Language	English