Toyota Celica 2005, Repair Manual

Page: 868 / 2497

DIC6C − 02
FI0534
D07259
Hand − held tester
DLC3
− DIAGNOSTICS AUTOMATIC TRANSAXLE (U240E)
DI − 669
2005 CELICA (RM1131U)
PRE − CHECK
1. DIAGNOSIS SYSTEM
(a) Description
S
When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect an OBD II scan tool complying
with SAE J1987 or hand
− held tester, to the vehicle
and read off various data output from the vehicle’s
ECM.
S
OBD II regulations require that the vehicle’s on −
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the computer itself or
in drive system components which affect vehicle
emissions. In addition to the MIL lighting up when
a malfunction is detected, the applicable DTCs pre-
scribed by SAE J2012 are recorded in the ECM
memory (See page DI
− 335).
If the malfunction does not occur in 3 consecutive trips, the MIL
goes off but the DTCs remain recorded in the ECM memory.
S
To check the DTCs, connect an OBD II scan tool or
hand
− held tester to DLC3 on the vehicle. The OBD
II scan tool or hand − held tester also enables you to
erase the DTCs and check freeze frame data and
various forms of engine data (For operating instruc-
tions, see the instruction book).
S
DTCs include SAE controlled codes and Manufac-
turer controlled codes.
SAE controlled codes must be set as prescribed by
the SAE, while Manufacturer controlled codes can
be set freely by the manufacturer within the pre-
scribed limits (See DTC chart on page DI
− 693).
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