1997 TOYOTA SUPRA fuel pressure

DI4SJ-01
S04073
Throttle Control ECU
VSV for Intake
Air Control Valve
(VSV1)
VSV for EXhaust
Bypass Valve
(VSV3) Heated Oxygen Sensor
(Bank 1 Sensor 1)
Ignition Coil
Mass Air Flow Meter
(Intake Air Temp. Sensor)
Engine Coolant Temp.
Sensor
VSV for Exhaust
Gas Control Valve
(VSV 2)
VSV for Waste
Gate Valve
(VSV4)VSV for EGR
ECM
IAC Valve
DLC1EGR Gas Temp. Sensor
Ignition Switch
Combination Meter
& Telltale Light RH
Fuel Pump ECU
Fuel Pump
No.1 Vehicle Speed Sensor
DLC3
Park/Neutral Position Switch
Stop Light Switch
Heated Oxygen Sensor
(Bank 1 Sensor 2) Igniter
Knock Sensor 2
Camshaft Position Sensor No.2
VSV for EVAP
Turbo Pressure Sensor
Camshaft Position Sensor No.1
Throttle Position Sensor
Sub Throttle Actuator Knock Sensor 1
Sub Throttle Position Sensor
Crankshaft Position Sensor
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-163
391 Author
: Date
:
1997 SUPRA (RM502U)
PARTS LOCATION

DI4SL-01
- DIAGNOSTICSENGINE (2JZ-GTE)
DI-169
397 Author
: Date
:
1997 SUPRA (RM502U)
PROBLEM SYMPTOMS TABLE
When the malfunction code is not confirmed in the DTC check and the problem still can not be confirmed
in the basic inspection, then proceed to this step and perform troubleshooting according to the numbered
order given in the table below.
SymptomSuspect AreaSee page
Does not start (Engine does not crank)1. Starter and Starter relayST-14, ST-16
Does not start (No initial combustion)
1. ECM power source circuit
2. Fuel pump control circuit
3. Engine control module (ECM)DI-304
DI-248
IN-18
Does not start (No complete combustion)1. Fuel pump control circuitDI-248
Difficult to start (Engine cranks normally)
1. Starter signal circuit
2. Fuel pump control circuit
3. CompressionDI-301
DI-248
EM-3
Difficult to start (Cold engine)1. Starter signal circuit
2.Fuel pump control circuitDI-301
DI-248
Difficult to start (Hot engine)
1. Starter signal circuit
2. Fuel pressure control circuit
3. Fuel pump control circuitDI-301
DI-309
DI-248
Poor idling (High engine idle speed)1. A/C signal circuit
2. ECM power source circuitDI-722
DI-304
Poor idling (Low engine idle speed)1. A/C signal circuit
2. Fuel pump control circuitDI-722
DI-248
Poor idling (Rough idling)1. Compression
2. Fuel pump control circuitEM-3
DI-248
Poor idling (Hunting)1. ECM power source circuit
2. Fuel pump control circuitDI-304
DI-248
Poor Driveability (Hesitation/Poor acceleration)1. Fuel pump control circuit
2. A/T faultyDI-248
DI-391
Poor Driveability (Surging)1. Fuel pump control circuitDI-248
Engine stall (Soon after starting)1. Fuel pump control circuitDI-248
Engine stall (During A/C operation)1. A/C signal circuit
2. Engine control module (ECM)DI-722
IN-18

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-201
429 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0171 System too Lean (Fuel Trim)
DTC P0172 System too Rich (Fuel Trim)
CIRCUIT DESCRIPTION
ºFuel trimº refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short-term fuel trim and long-term fuel trim.
ºShort-term fuel trimº is the short-term fuel compensation used to maintain the air-fuel ratio at its ideal
theoretical value. The signal from the heated oxygen sensor indicates whether the air-fuel ratio is RICH or
LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air-fuel ratio is rich,
and an increase in fuel volume if it is lean.
ºLong-term fuel trimº is overall fuel compensation carried out long-term to compensate for continual devi-
ation of the short-term fuel trim from the central value due to individual engine differences, wear over time
and changes in the usage environment.
If both the short-term fuel trim and long-term fuel trim are LEAN or RICH beyond a certain value, it is de-
tected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the RICH side
(2 trip detection logic)

Air intake (hose loose)

Fuel line pressure

Injector blockage

Heated oxygen sensor malfunction

Mass air flow meter

Engine coolant temp. sensor
P0172
When the air fuel ratio feedback is stable after engine warning
up, the fuel trim is considerably in error on the LEAN side
(2 trip detection logic)

Fuel line pressure

Injector blockage, leak

Heated oxygen sensor malfunction

Mass air flow meter

Engine coolant temp. sensor
HINT:

When DTC P0171 is recorded, the actual air-fuel ratio is on the LEAN side. When DTC P0172 is re-
corded, the actual air-fuel ratio is on the RICH side.

If the vehicle runs out of fuel, the air-fuel ratio is LEAN and DTC P0171 is recorded. The MIL then
comes on.

If the total of the short-term fuel trim value and long-term fuel trim value is within ± 35 %, the system
is functioning normally.
INSPECTION PROCEDURE
1 Check air induction system (See page SF-1).
NG Repair or replace.
OK
DI4SY-01

DI-202
- DIAGNOSTICSENGINE (2JZ-GTE)
430 Author
: Date
:
1997 SUPRA (RM502U)
2 Check for heated oxygen sensor data.
PREPARATION:
(a) Connect the OBDII scan tool or TOYOTA hand-held tester to the DLC3.
(b) Warm up engine to normal operating temperature.
CHECK:
Read the heated oxygen sensor output voltage and short-term fuel trim.
HINT:
Read the values for the same bank.
RESULT:
PatternHeated oxygen sensor output voltageShort-term fuel trim
1Lean condition (Changes at 0.55 V or less)Changes at about + 20 %
2Rich condition (Changes at 0.4 V or more)Changes at about - 20 %
3Except 1 and 2
3 Check for heated oxygen sensor
(See page DI-193).
1,2
3 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
4 Check injector injection (See page SF-25).
NG Replace injector.
OK

DI-204
- DIAGNOSTICSENGINE (2JZ-GTE)
432 Author
: Date
:
1997 SUPRA (RM502U)
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred.
When the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected during the any
particular 200 or 1,000 revolutions
Ignition system

Injector
P0301
P0302
P0303For any particular 200 revolutions of the engine, misfiring is
detected which can cause catalyst overheating (This causes
MIL to blink)
j

Fuel line pressure

EGR

Compression pressure


Valve clearance not to specificationP0303
P0304
P0305
P0306For any particular 1,000 revolutions of the engine, misfiring
is detected which causes a deterioration in emission (2 trip
detection logic)

Valve clearance not to specification

Valve timing

Mass air flow meter

Engine coolant temp. sensor
HINT:
When the 2 or more codes for a misfiring cylinder are recorded repeatedly but no Random Misfire code is
recorded, it indicates that the misfires were detected and recorded at different times.
DI4SZ-01

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).

- DIAGNOSTICSENGINE (2JZ-GTE)
DI-247
475 Author
: Date
:
1997 SUPRA (RM502U)
DTC P1100 Barometric Pressure Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
The BARO sensor is built into the ECM. This is a semiconductor pressure sensor with properties which cause
its electrical resistance to change when stress is applied to the sensor's crystal (silicon) (piezoelectric effect).
This sensor is used to detect the atmospheric (absolute) pressure and outputs corresponding electrical sig-
nals. Fluctuations in the air pressure cause changes in the intake air density, which can cause deviations
in the air-fuel ratio. The signals from BARO sensor are used to make corrections for these fluctuations. If
the ECM detects DTC P1100, the fail safe function operates and the atmospheric pressure is set at a
constant 760 mmHg.
DTC No.DTC Detecting ConditionTrouble Area
P1100Open or short detected in barometric pressure sensor circuit
(2 trip detection logic)
ECM
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P1100) being output?
YES Go to relevant DTC chart.
NO
Replace ECM.
DI4TA-01

S05428
Battery
B
W-B
EFI No.1
EB
R/B
No.2
2A12
B-D
R/B
No.2
2
2 2 2
51
32
EFI No.2 Relay
B-R L-O
E1 L-O
B-R
B-R 5EA2
BP1
BI
2
W-B
W-B
Fuel
Pump
5 4
L
6BP1
5L-R
FP4 Fuel Pump ECU
B+
B+
E
1DI FPCVSV for
Fuel Pressure
12
W-L
IB1IC2
73
22
21
B
A
A
V-WV-W
V-W
GG
G 1211
124IC2IJ1
IJ1
IC2
DI FPC5VEO1 FPUECM
5
10 DI-248
- DIAGNOSTICSENGINE (2JZ-GTE)
476 Author
: Date
:
1997 SUPRA (RM502U)
DTC P1200 Fuel Pump Relay/ECU Circuit Malfunction
CIRCUIT DESCRIPTION
The fuel pump speed is controlled at 2 steps (high speed, low speed) by the condition of the engine (starting,
light load, heavy load), when the engine starts (STA ON), the ECM sends a Hi signal (about 5 V) to the fuel
pump ECU (FPC terminal).
The fuel pump ECU then outputs Hi voltage (battery positive voltage) to the fuel pump so that the fuel pump
operates at high speed.
After the engine starts, during idling or light loads, the ECM outputs a Low signal (about 2.5 V) to the fuel
pump ECU, the fuel pump ECU outputs Low voltage (about 9 V) to the fuel pump and causes the fuel pump
to operate at low speed.
If the intake air volume increases (high engine load), the ECM sends a Hi signal to the fuel pump ECU and
causes the fuel pump to operate at high speed.
DTC No.DTC Detecting ConditionTrouble Area
Open or short in fuel pump circuit for 1 sec. or more with en-
gine speed 1,000 rpm or less
(2 trip detection logic)

Open or short in fuelpumpECU circuit
P1200
Open in input circuit of fuel pump ECU (FPC) with engine
speed 1,000 rpm or less
(2 trip detection logic)

Open or short in fuel pump ECU circuit

Fuel pump ECU

ECM power source circuit

Fuel pump
Open or short in diagnostic signal line (DI) of fuel pump ECU
with engine speed 1,000 rpm or less
(2 trip detection logic)
Fuel um

ECM
WIRING DIAGRAM
DI4TB-01