Page 633 of 1807
A00706
ON
EGR Gas
Temp. Sensor
2
1ECM
46
65
B
BTHG
5V
E2
Check Harness A
ECM
B46, 65
E2
(-) THG
(+)
DI-220
- DIAGNOSTICSENGINE (2JZ-GTE)
448 Author: Date:
1997 SUPRA (RM502U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Connect Check Harness A (See page DI-164).
(b) Connect between terminals THG and E2 of ECM.
HINT:
EGR gas temp. sensor connector is disconnected. Before
checking, do a visual check and connect pressure check for the
ECM connector (See page IN-28).
CHECK:
Read EGR gas temperature on the TOYOTA hand-held tester.
OK:
EGR gas temp.: 159.3°C (318.7°F)
OK Open in harness between terminals 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
Page 634 of 1807
A00595
ON
Air
Air
E
F
E
F
System: ON
System: OFF
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-221
449 Author: Date:
1997 SUPRA (RM502U)
6 Check the VSV for EGR.
PREPARATION:
Select the ACTIVE TEST mode on the TOYOTA hand-held tes-
ter.
CHECK:
Check operation of VSV when it is operated by the TOYOTA
hand-held tester.
OK:
EGR system is ON:
Air from pipe E flows out through pipe F.
EGR system 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-69).
NG Replace VSV for EGR.
OK
Check for open in harness and connector be-
tween VSV and ECM (See page IN-28).
8 Check EGR vacuum modulator (See page EC-7).
NG Repair or replace.
OK
Page 635 of 1807
DI-222
- DIAGNOSTICSENGINE (2JZ-GTE)
450 Author: Date:
1997 SUPRA (RM502U)
9 Check EGR valve (See page EC-7).
NG Repair or replace.
OK
10 Check value of EGR gas temp. sensor.
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.
(c) Select the ACTIVE TEST mode on the TOYOTA hand-held tester. (EGR system ON)
(d) Race the engine at 4,000 rpm for 3 min.
CHECK:
Measure the EGR gas temp. while racing engine at 4,000 rpm.
OK:
EGR gas temp. after 3 min.: 120°C (248°F) or more
NG Replace EGR gas temp. sensor.
OK
Check and replace ECM (See page IN-28).
Page 636 of 1807
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
Page 637 of 1807
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
Page 638 of 1807
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).
Page 639 of 1807
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).
Page 640 of 1807

- 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