05L7I -- 04
FI2547
A98444
Intelligent Tester ll
DLC3
05 -- 30
--
DIAGNOSTICS
ECD SYSTEM (1ND -- TV)
COROLLA Supplement (RM1129E)
DIAGNOSIS SYSTEM
1. DESCRIPTION
When troubleshooting Euro -- OBD (On -- Board Diagnostic) ve -
hicle, an intelligent tester ll or OBD scan tool must be connected
to the DLC3 (Data Link Connector 3) of the vehicle. Various
data in the vehicle’s ECM (Engine Control Module) can be then
read.
Euro -- OBD regulations require that the v ehicle’s on -- board
computer illuminates the MIL (Malfunction Indicator Lamp) in
the instrument panel when the c omputer detects a malfunction
in:
1) The emission control system and components.
2) The power train c ontrol c omponents (which affect v ehicle
emissions).
3) The computer itself.
In addition, the applicable DTCs (Diagnostic Trouble Codes)
prescribed by ISO 15031 -- 4 are recorded in the ECM memory.
If the malfunction does not recur in 3 consecutive trips, the MIL
turns off automatically but the DTCs remain recorded in the
ECM memory.
To check the DTCs, connect an intelligent tester II to the DLC3.
The tester displays DTCs, freeze frame data, and variety of en -
gine data. The DTCs and freeze frame data c an be erased with
the tester
(refer to DTC CHECK/CLEAR on page 05 -- 33 ).
2. NORMAL MODE AND CHECK MODE
The diagnosis system operates in normal mode during normal
vehicle use. In normal mode, 2 trip detection logic is used to en -
sure accurate detection of malfunctions. Check mode is also
available as an option for technicians. In check mode, 1 trip
detection logic is used for simulating malfunction symptoms
and increasing the system’s ability to detect malfunctions, in-
cluding intermittent problems
To Alphabetical Index
To Sub Index
TOYOTA COROLLA REPAIR MANUAL SUPP 1129E