DI1I6--01
FI0534
A01749
Hand--Held Tester
DLC3
--
DIAGNOSTICS
ENGINE (2RZ--FE, 3RZ--FE)
DI--75
PRE--CHECK
1. DIAGNOSIS SYSTEM
(a)
Description
S
When troubleshooting Multiplex OBD (M--OBD) ve-
hicles, the only difference from the usual trouble-
shooting procedure is that you connect the hand--
held tester to the vehicle, and read off various data
output from the vehicle’s ECU.
S
The vehicle’s on--board computer lights up the
check engine warning light (CHK ENG) on the
instrument panel when the computer detects a mal-
function in the computer itself or in drive system
components. In addition to the check engine warn-
ing light lighting up when a malfunction is detected,
the applicable Diagnosis Trouble Code (DTC) are
recorded in the ECU memory.
If the malfunction has been repaired, the check en-
gine warning light goes off automatially but the
DTCs remain recorded in the ECU memory.
S
To check the DTCs, connect the hand--held tester
to Data Link Connector 3 (DLC3) on the vehicle. or
read the number of blinks of the check engine warn-
ing light when TC and CG terminals on the DLC3
are connected. The hand--held tester also enables
you to erase the DTCs and activate the several ac-
tuaters and check freezed frame data and vaious
forms of engine data (For operating instructions,
see the hand--held
tester instruction book.)
S
The diagnosis system operates in normal mode
during normal vehicle use. It also has a check (test)
mode for technicans to simulate malfunction symp-
toms and troubleshoot. Most DTCs use 2 trip detec-
tion logic to prevent erroneous detection and en-
sure thorough malfunction detection. By switching
the ECU to check (test) mode using hand--held tes-
ter when troubleshooting, the techinician can cause
the check engine warning (CHK ENG) to light up for
a malfunction that is only detected once or momen-
tarily. (Hand--held tester only)
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3RZ-F,3RZ-FE
