1997 TOYOTA SUPRA check engine

S03243S03486
A03069
EGR Gas Temp. Sensor
Connector
BE6653S03244S03487A03070
ON
Wire Harness Side
1(-)
2(+)
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-223
451 Author
: Date
:
1997 SUPRA (RM502U)
OBDII scan tool (excluding TOYOTA hand-held tester)
1 Check resistance of EGR gas temp. sensor.
PREPARATION:
Disconnect EGR gas temp. sensor connector.
CHECK:
Measure resistance between terminals of EGR gas temp. sen-
sor connector.
OK:
Resistance: 600 kW or less.
HINT:
If there is open circuit, ohmmeter indicates 720 kW or more.
NG Check and replace EGR gas temp. sensor
(See page SF-77).
OK
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect EGR gas temp. sensor connector.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals of EGR gas temp. sensor
wire harness side connector.
OK:
Voltage: 4.5 - 5.5 V
OK Go to step 4.
NG

A00709
ONCheck Harness A
ECM
B46, 65
E2(-)
THG(+)
DI-224
- DIAGNOSTICSENGINE (2JZ-GTE)
452 Author
: Date
:
1997 SUPRA (RM502U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminals THG and E2 of ECM con-
nector.
HINT:
EGR gas temp. sensor connector is disconnected.
OK:
Voltage: 4.5 - 5.5 V
OK Open in harness between terminal E2 or THG.
repair or replace harness.
NG
Confirm connection at ECM.
If OK, replace ECM.
4 Check connection of vacuum hose, EGR hose (See page EC-2).
NG Repair or replace.
OK
5 Check EGR system (See page EC-7).
OK Check and replace ECM (See page IN-28).
NG

A00710
ONCheck Harness A
B75
EGRON
OFF
Air
Air
E
FE
F
VSV: ON VSV: OFF
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-225
453 Author
: Date
:
1997 SUPRA (RM502U)
6 Check the VSV for EGR.
PREPARATION:
(a) Connect Check Harness A to the connectors on the wire
harness side (See page DI-164).
HINT:
The other side of Check Harness A is not connected to the ECM
terminals.
(b) Turn ignition switch ON.
CHECK:
Check VSV function
(1) Connect between terminal EGR of ECM connector
and body ground (ON).
(2) Disconnect between terminal EGR of ECM connec-
tor and body ground (OFF).
OK:
(1) VSV is ON:
Air from pipe E flows out through pipe F.
(2) VSV is OFF:
Air does not flow from pipe E to pipe F.
OK Go to step 8.
NG
7 Check operation of the VSV for EGR (See page SF-77).
NG Replace VSV for EGR.
OK
Check for open in harness and connector be-
tween engine room R/B and ECM
(See page IN-28).

S03243S03486
A03069
EGR Gas Temp. Sensor
Connector
DI-226
- DIAGNOSTICSENGINE (2JZ-GTE)
454 Author
: Date
:
1997 SUPRA (RM502U)
8 Check EGR vacuum modulator (See page EC-7).
NG Repair or replace.
OK
9 Check EGR valve (See page EC-7).
NG Repair or replace.
OK
10 Check resistance of EGR gas temp. sensor.
PREPARATION:
(a) Disconnect EGR gas temp. sensor connector.
(b) For EGR system is ON, connect between terminal EGR
of ECM connector and body ground
(See page DI-217, step 5).
(c) Start the engine and warm it up.
(d) Race the engine at 4,000 rpm for 3 min.
CHECK:
Measure the resistance of the EGR gas temp. sensor while rac-
ing the engine at 4,000 rpm.
OK:
Resistance of EGR gas temp. senor after 3 min. 9.0 kW
or less
HINT:
Resistance: 188.6 - 439.0 kW at 20°C (68°F).
NG Replace EGR gas temp. sensor.
OK
Check and replace ECM (See page IN-28).

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-227
455 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0402 Exhaust Gas Recirculation Flow Excessive
Detected
CIRCUIT DESCRIPTION
Refer To Exhaust Gas Recirculation Flow Insufficient Detected on page DI-217.
DTC No.DTC Detecting ConditionTrouble Area
P0402
EGR gas temp. sensor value is high during EGR cut-off when
engine is cold (Race engine at about 4,000 rpm without load so
that vacuum is applied to port E)
(2 trip detection logic)
EGR valve stuck open

EGR VSV open malfunction

Open in VSV circuit for EGR
Sh t i EGR t i itEGR valve is always open
(2 trip detection logic)
Short in EGR gas temp. sensor circuit

ECM
See DTC P0401 for CONFIRMATION CHECK DRIVING PATTERN and WIRING DIAGRAM.
INSPECTION PROCEDURE
TOYOTA hand-held tester
1 Connect the TOYOTA hand-held tester and read EGR gas temperature value.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn ignition switch ON and push the TOYOTA hand-held tester main switch ON.
CHECK:
Read EGR gas temperature on the TOYOTA hand-held tester.
OK:
EGR gas temp.: 150°C (302°F) or less. (Not immediately after driving)
HINT:
If there is a short circuit, the TOYOTA hand-held tester indicates 159.3°C (318.7°F).
OK Go to step 4.
NG
DI4T4-01

A00174
ON
EGR Gas Temp. Sensor
2
146
65
B
BTHG
ECM
5V
E2
A00691
ON
EGR Gas Temp. SensorECM
5V
THG
E2
ECM
B Connector
DI-228
- DIAGNOSTICSENGINE (2JZ-GTE)
456 Author
: Date
:
1997 SUPRA (RM502U)
2 Check for short in harness and ECM.
PREPARATION:
Disconnect the EGR gas temp. sensor connector.
CHECK:
Read EGR gas temp. on the TOYOTA hand-held tester.
OK:
EGR gas temp.: 3.1°C (37.6°F)
OK Replace EGR gas temp. sensor.
NG
3 Check for short in harness or ECM.
PREPARATION:
(a) Disconnect the B connector from ECM
(See page DI-164).
HINT:
EGR gas temp. sensor is disconnected.
(b) Turn ignition switch ON.
CHECK:
Read EGR gas temp. on the TOYOTA hand-held tester.
OK:
EGR gas temp.: 3.1°C (37.6°F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN-28).

S03243S03486
A03069
EGR Gas Temp. Sensor
Connector
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-229
457 Author
: Date
:
1997 SUPRA (RM502U)
4 Check the VSV for EGR (See page DI-217, step 6).
OK Check EGR valve (See page EC-7).
NG
5 Check operation of the VSV for EGR (See page SF-77).
NG Replace VSV for EGR.
OK
Check for short in harness and connector
between VSV and ECM (See page IN-28).
OBDII scan tool (excluding TOYOTA hand-held tester)
1 Check resistance of EGR gas temp. sensor.
PREPARATION:
Disconnect the EGR gas temp. sensor connector.
CHECK:
Measure resistance between terminals of EGR gas temp. sen-
sor connector.
OK:
Resistance: 2.5 kW or more.
(Not immediately after driving)
HINT:
If there is short circuit, ohmmeter indicates 200 W or less.
NG Replace EGR gas temp. sensor.
OK

DI-230
- DIAGNOSTICSENGINE (2JZ-GTE)
458 Author
: Date
:
1997 SUPRA (RM502U)
2 Check for short in harness and connector between EGR gas temp. sensor and
ECM (See page EC-7).
NG Repair or replace harness or connector.
OK
3 Check the VSV for EGR (See page DI-217, step 6).
OK Check EGR valve (See page EC-7).
NG
4 Check operation of the VSV for EGR (See page IN-18).
NG Replace VSV for EGR.
OK
5 Check for short in harness and connector between VSV and ECM
(See page EC-7).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page EC-7).