trip computer TOYOTA SUPRA 1997 Service Repair Manual

DI4SH-01
FI0534
Q08242
TOYOTA Hand-Held Tester
DLC3
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-147
375 Author
: Date
:
1997 SUPRA (RM502U)
PRE-CHECK
1. DIAGNOSIS SYSTEM
(a) Description
When troubleshooting OBD II vehicles, the only differ-
ence from the usual troubleshooting procedure is that you
connect to the vehicle the OBD II scan tool complying with
SAE J1978 or TOYOTA hand-held tester, and read off
various data output from the vehicle's ECM.
OBD II regulations require that the vehicle's on-board
computer lights up the Malfunction Indicator Lamp (MIL)
on the instrument panel when the computer detests a
malfunction in the computer itself or in drive system com-
ponents which affect vehicle emissions. In addition to the
MIL lighting up when a malfunction is detected, the appli-
cable Diagnostic Trouble Codes (DTC) prescribed by
SAE J2012 are recorded in the ECM memory.
(See page DI-158)
If the malfunction does not reoccur in 3 trips, the MIL goes
off but the DTC remain recorded in the ECM memory.
To check the DTC, connect the OBD II scan tool or TOYO-
TA hand-held tester to Data Link Connector 3 (DLC3) on
the vehicle. The OBD II scan tool or TOYOTA hand-held
tester also enables you to erase the DTC and check
freezed frame data and various forms of engine data. (For
operating instructions, see the OBD II scan tool's instruc-
tion book.)
DTC include SAE controlled codes and Manufacturer
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 prescribed limits.
(See DTC chart on page DI-158)
The diagnosis system operates in normal mode during
normal vehicle use. It also has a check mode for techni-
cians to simulate malfunction symptoms and trouble-
shoot. Most DTC use 2 trip detection logic* to prevent er-
roneous detection and ensure thorough malfunction
detection. By switching the ECM to check mode when
troubleshooting, the technician can cause the MIL to light
up for a malfunction that is only detected once or momen-
tarily. (TOYOTA hand-held tester only)
(See page DI-147)
*2 trip detection logic: When a logic malfunction is first de-
tected, the malfunction is temporarily stored in the ECM
memory. If the same malfunction is detected again during
the second drive test, this second detection causes the
MIL to light up.

S05422
To Turbo
Charcoal
Canister
Fuel Tank
ECMIntake Manifold VSV for
EVAP
S01079
Battery
EB
W-B
BB-W
R/B No.2
EFI No.1
EFI Main Relay
2 2A
2
2 2
2
35
1 2
B-R
B-YB-REA22VSV for EVAP
1274
B
ECM
EVAP
E01
B+
GR24
A
M-REL
V
EA18 1 DI-234
- DIAGNOSTICSENGINE (2JZ-GTE)
462 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0441 Evaporative Emission Control System
Incorrect Purge Flow
CIRCUIT DESCRIPTION
To reduce HC emissions, evaporated fuel from the fuel tank is routed through the charcoal canister to the
intake manifold for combustion in the cylinders.
The ECM changes the duty signal to the VSV for EVAP so that the intake quantity of HC emissions is ap-
propriate for the driving conditions (engine load, engine speed, etc.) after the engine is warme up.
DTC No.DTC Detecting ConditionTrouble Area
P0441
The proper response to the computer command does not oc-
cur
(2 trip detection logic)

Open or short in VSV circuit for EVAP

VSV for EVAP

Vacuum hose blocked or disconnected

ECM

Charcoal canister
WIRING DIAGRAM
DI4T6-01