Page 625 of 1807
A00701
OFF
B50, 49
KNK1KNK2Check Harness A
DI-210
- DIAGNOSTICSENGINE (2JZ-GTE)
438 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
HINT:
DTC P0325 is for the knock sensor circuit on the front side.
DTC P0330 is for the knock sensor circuit on the rear side.
1 Check continuity between terminal KNK1, KNK2 of ECM connector and body,
ground.
PREPARATION:
Connect Check Harness A to the connectors on the wire har-
ness side (See page DI-164).
HINT:
The other side of Check Harness A is not connected to the ECM
terminals.
CHECK:
Measure resistance between terminal KNK1, KNK2 of ECM
connector and body ground.
HINT:
Connect terminal KNK1 to knock sensor 1.
Connect terminal KNK2 to knock sensor 2.
OK:
Resistance: 1 MW or higher
OK Go to step 3.
NG
2 Check knock sensor (See page SF-75).
NG Replace knock sensor.
OK
3 Check for open and short in harness and connector between ECM and knock
sensor (See page IN-28).
NG Repair or replace harness or connector.
OK
Page 626 of 1807
A00702
KNK Signal Waveform
0.5 V/
Division
0 V
5 m sec./Division
0.5 V/
Division
0 V
100 sec./Division
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-21 1
439 Author: Date:
1997 SUPRA (RM502U)
4 Does malfunction disappear when a good knock senor is installed?
YES Replace knock sensor.
NO
Check and replace ECM (See page IN-28).
Reference INSPECTION USING OSCILLOSCOPE
With the engine racing (4,000 rpm) measure waveform
between terminals KNK1, KNK2 of ECM and body
ground.
HINT:
The correct waveform is as shown.
Spread the time on the horizontal axis, and confirm that
period of the wave is 123
sec. (Normal, mode vibration
frequency of knock sensor: 8.1 KHz).
HINT:
If normal mode vibration frequency is not 8.1 KHz, the sensor
is malfunctioning.
Page 627 of 1807

S03471
Camshaft Position
Sensor No.1
Camshaft Position
Sensor No.2
Camshaft Position
Sensor1
1
1 2
2
2W
O
B-W
L
B-R
BR BR26
6
25
27
7 B
B
B
B
BG1
G1
G2
NE
NE
E1 ECM DI-212
- DIAGNOSTICSENGINE (2JZ-GTE)
440 Author: Date:
1997 SUPRA (RM502U)
DTC P0335 Crankshaft Position Sensor ºAº Circuit
Malfunction
CIRCUIT DESCRIPTION
The crankshaft position sensor (NE signal) consist of a signal plate and a pick up coil. The NE plate has 24
teeth and is mounted on the crankshaft.
When the camshaft rotates, the protrusion on the signal plate and the air gap on the pick up coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pick up coil.
The NE signal sensor generates 24 signals for every engine revolution. The ECM detects the standard
crankshaft angle based on the G1, G2 signals, detects the actual crankshaft angle and the engine speed
by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
P0335
No crankshaft position sensor signal (NE signal) to ECM dur-
ing cranking
(2 trip detection logic)Open or short in crankshaft position sensor circuit for NE
signal
C k h ft iti f NE i lP0335No crankshaft position sensor signal (NE signal) to ECM with
engine speed 600 rpm or more
(2 trip detection logic)Crankshaft position sensor for NE signal
Starter
ECM
WIRING DIAGRAM
DI4T1-01
Page 628 of 1807
P23868A07740A06718
FI6519A03396
G. NE Signal Waveforms
5 V/Division
20 m sec./Division (Idling) G1
G2
NE
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-213
441 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor for NE signal.
PREPARATION:
Disconnect crankshaft position sensor connector.
CHECK:
Measure resistance of crankshaft position sensor.
OK:
Resistance
Cold835 ~ 1,400 W
Hot1,060 ~ 1,645 W
ºColdº is from -10°C (14°F) to 50°C (122°F) and ºHotº is from
50°C (122°F) to 100°C (212°F).
Reference INSPECTION USING OSCILLOSCOPE
During cranking or idling, check between ECM terminals
G1, G2 and G1, NE and NEof engine control module.
HINT:
The correct waveforms are as shown.
NG Replace distributor.
OK
2 Check for open and short in harness and connector between ECM and crank-
shaft position sensor for NE signal (See page IN-28).
NG Repair or replace harness or connector.
OK
Page 629 of 1807
DI-214
- DIAGNOSTICSENGINE (2JZ-GTE)
442 Author: Date:
1997 SUPRA (RM502U)
3 Inspect sensor installation and teeth of signal plate.
NG Tighten the sensor.
Replace signal plate.
OK
Check and replace ECM (See page IN-28).
Page 630 of 1807

FI6975
Throttle ValveVSVECM
EGR Valve
EGR Gas
Temp. Sensor
Exhaust Gas
Air
Intake
ChamberEGR
Vacuum
Modulator
S01078
R/B No.2
Battery R/B No.2
B
B-W
W-B EFI No.1
1
2A2 2
2 2 2
3
2 1
5
EFI Main Relay
B-Y B-R2
8
EA2
EA1VSV For EGR1
2 B-R P
GR
EGR Gas
Temp. Sensor
2
1BR-Y
W-BECM
75
24
46
65B
B
B
BEGR
E01
+B
M-REL
5V
THG
E2
EB
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-217
445 Author: Date:
1997 SUPRA (RM502U)
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combustion temperature and reduce
NOx emissions. The amount of EGR is regulated by the EGR vacuum modulator according to the engine
load.
If even one of the following conditions is fulfilled, the VSV is
turned ON by a signal from the ECM. This results in atmospher-
ic air acting on the EGR valve, closing the EGR valve and shut-
ting off the exhaust gas (EGR cut-off).
Under the following conditions, EGR is cut to maintain driveabil-
ity.
Before the engine is warmed up.
During deceleration (throttle valve closed).
Light engine load (amount of intake air very small).
Engine racing.
DTC No.DTC Detecting ConditionTrouble Area
P0401
After the engne is warmed up and run at 80 km/h (50 mph) for
3 to 5 min., the EGR gas temperature sensor value does not
exceed 45°C (113°F) above the ambient air temperature
(2 trip detection logic)EGR valve stuck closed
Short in VSV circuit for EGR
Open in EGR gas temp. sensor circuit
EGR hose disconnected
ECM
WIRING DIAGRAM
DI4T3-01
Page 631 of 1807

P20769
70 - 90 km/h
(43 - 56 mph)
Idling
IG SW OFF
Warm up
3 - 5 min.
2 min.3 - 5 min.
2 min.Time
(7) (6)
(5) (7) (3)
(2) (1) DI-218
- DIAGNOSTICSENGINE (2JZ-GTE)
446 Author: Date:
1997 SUPRA (RM502U)
SYSTEM CHECK DRIVING PATTERN
(1) Connect the OBDII scan tool or TOYOTA hand-held tester to the DLC3.
(2) Start the engine and warm it up with all accessories switched OFF.
(3) Run the vehicle at 70 - 90 km/h (43 - 56 mph) for 3 min. or more.
(4) Idle the engine for about 2 min.
(5) Stop at safe place and turn the ignition switch OFF.
(6) Start the engine and do steps (3) and (4) again.
(7) Check the ºREADINESS TESTSº mode on the OBDII scan tool or TOYOTA hand-held tester. If ºCOMPLº
is displayed and the MIL does not light up, the system is normal. If ºINCMPLº is displayed and the MIL does
not light up, run the vehicle again and check it.
HINT:
ºINCMPLº is displayed when either condition (a) or (b) exists.
The system check is incomplete.
There is a malfunction in the system.
If there is a malfunction in the system, the MIL will light up after steps (2) to (6) above are done.
Page 632 of 1807
A00168
ON
EGR Gas Temp.
Sensor
2
146
65
B
BTHG
ECM
5V
E2
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-219
447 Author: Date:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
TOYOTA hand-held tester
1 Connect the TOYOTA hand-held tester and read value of EGR gas temperature.
PREPARATION:
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Turn ignition switch ON and TOYOTA hand-held tester main switch ON.
CHECK:
Read EGR gas temperature on the TOYOTA hand-held tester.
OK:
EGR gas temp.: 10°C (50°F) or more
HINT:
If there is an open circuit, the TOYOTA hand-held tester indicates 3.1°C (37.6°F).
OK Go to step 4.
NG
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the EGR gas temp. sensor connector.
(b) Connect sensor wire harness terminals together.
(c) Turn ignition switch ON.
CHECK:
Read EGR gas temperature on the TOYOTA hand-held tester.
OK:
EGR gas temp.: 159.3°C (318.7°F)
OK Confirm good connection at sensor.
If OK, replace EGR gas temp. sensor.
NG