Toyota Celica 2005, Repair Manual

Page: 494 / 2497

DID57 − 01
FI0534
D07259
Hand − Held Tester
DLC3
− DIAGNOSTICS ENGINE (2ZZ − GE)
DI − 295
2005 CELICA (RM1131U)
PRE − CHECK
1. DIAGNOSIS SYSTEM
(a) Description
S
When troubleshooting On − Board Diagnostic (OBD
ll) vehicles, the vehicle must be connected to the
OBD ll scan tool (in compliance with SAE J1978) or
the hand
− held tester. Various data output from the
vehicle’s ECM can then be read.
S
OBD ll regulations require that the vehicle’s on −
board computer illuminates the Malfunction Indica-
tor Light (MIL) on the instrument panel when the
computer detects a malfunction in: 1) the emission
control system/components, or 2) the power train
control components (which affect vehicle emis-
sions), or 3) the computer. In addition, the applica-
ble Diagnostic Trouble Codes (DTCs) prescribed by
SAE J2012 are recorded in the ECM memory
(See page DI
− 335).
If the malfunction does not reccur in 3 consecutive trips, the MIL
goes off automatically but the DTCs remain recorded in the
ECM memory.
S
To check the DTC, connect the hand − held tester or
OBD II scan tool to the Data Link Connector 3
(DLC3) of the vehicle. The hand
− held tester or OBD
II scan tool also enables you to erase the DTC and
check the freeze frame data and various forms of
engine data (See the instruction manual for the
OBD ll scan tool or the hand
− held tester). The DTC
includes SAE controlled codes and manufacturer
controlled codes. SAE controlled codes must be set
according to the SAE, while manufacturer con-
trolled codes can be set by a manufacturer with cer-
tain restrictions (See the DTC chart on page
DI
− 335).
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