TOYOTA SUPRA 1997 Service Repair Manual

P11799 IG0317 IG0151
A03065
1.1 mm
DI-206
- DIAGNOSTICSENGINE (2JZ-GTE)
434 Author
: Date
:
1997 SUPRA (RM502U)
INSPECTION PROCEDURE
1 Check spark plug and spark of misfiring cylinder.
PREPARATION:
(a) Remove the ignition coil (See page IG-6).
(b) Remove the spark plug.
CHECK:
(a) Check the carbon deposits on electrode.
(b) Check electrode gap.
OK:
(1) No large carbon deposit present.
Not wet with gasoline or oil.
(2) Electrode gap: 1.1 - 1.3 mm
(0.043 - 0.051 in.)
PREPARATION:
(a) Install the spark plug to the ignition coil, and connect the
ignition coil connector.
(b) Ground the spark plug.
(c) Disconnect injector connector.
CHECK:
Check if spark occurs while the engine is being cranked.
NOTICE:
To prevent excess fuel being injected from the injectors
during this test, don't crank the engine for more than 5 - 10
sec. at a time.
OK:
Spark jumps across electrode gap.
NG Replace or check ignition system (See page
IG-1).
OK

A00700
ON
Check Harness A
ECM
B20, 19, 18, 17, 16, 15
#10
(+)#20
(+)#30
(+)#40
(+)#50
(+)#60
(+)
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-207
435 Author
: Date
:
1997 SUPRA (RM502U)
2 Check voltage of ECM terminal for injector of failed cylinder.
PREPARATION:
(a) Connect Check Harness A (See page DI-164.).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between applicable terminal of ECM and body
ground.
OK:
Voltage: 9 - 14 V
OK Go to step 4.
NG
3 Check resistance of injector of misfiring cylinder (See page SF-25).
NG Replace injector.
OK
Check for open and short in harness and con-
nector between injector and ECM (See page
IN-28).
4 Check fuel pressure (See page SF-5).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF-1).
OK
5 Check injector injection (See page SF-25).

DI-208
- DIAGNOSTICSENGINE (2JZ-GTE)
436 Author
: Date
:
1997 SUPRA (RM502U)
NG Replace injector.
OK
6 Check EGR system (See page EC-7).
NG Repair EGR system.
OK
7 Check mass air flow meter and engine coolant temp. sensor (See page SF-38,
SF-73).
NG Repair or replace.
OK
Check the compression pressure (See page EM-3), valve clearance (See page EM-4) and valve
timing (See page EM-15).

P22425
Knock Sensor 1
(On front side)
1W
Knock Sensor 2
(On rear side)
1WB
B 50
49
KNK2 KNK1ECM
E1
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-209
437 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0325 Knock Sensor 1 Circuit Malfunction
DTC P0330 Knock Sensor 2 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensors are fitted one each to the front and rear of the left side of the cylinder block to detect engine
knocking. This sensor contains a piezoelectric element which generates a voltage when it becomes de-
formed, which occurs when the cylinder block vibrates due to knocking. If engine knocking occurs, ignition
timing is retarded to suppress it.
DTC No.DTC Detecting ConditionTrouble Area
P0325No knock sensor 1 signal to ECM with engine speed between
2,050 rpm and 5,950 rpm
Open or short in knock sensor 1 circuit

Knock sensor 1 (looseness)

ECM
P0330No knock sensor 2 signal to ECM with engine speed between
2,050 rpm and 5,950 rpm
Open or short in knock sensor 2 circuit

Knock sensor 2 (looseness)

ECM
If the ECM detects the above diagnosis conditions, it operates the fail safe function in which the corrective
retard angle value is set to the maximum value.
WIRING DIAGRAM
DI4T0-01

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

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.

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

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 NE
of 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

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).

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