fuel pressure TOYOTA CAMRY 1999 Service Repair Manual

DI±86
± DIAGNOSTICSENGINE
DTC P1190 Fuel Pressure Regulator Malfunction
CIRCUIT DESCRIPTION
The fuel pressure regulator regulates the fuel pressure by reducing the pressure of the compressed fuel from
the fuel tank to the fuel injection pressure, which is 785 kPa (8 kgf/cm
2, 114 psi).
Similar to the fuel shutoff valve for the fuel tank, a fuel shutoff valve is provided on the fuel inlet side of the
fuel pressure regulator to shutoff the supply of fuel when the engine is stopped or during abnormal condi-
tions.
A reservoir that traps the moisture and oil in the fuel is provided on the low pressure side.
A built±in relief valve is provided to protect the parts located on the low pressure side.
While the fuel pressure is being reduced by the fuel pressure regulator, the Joule±Thompson effect
associated with the expansion of the fuel causes the fuel pressure regulator to be cooled excessively, exert-
ing unfavorable influence on the rubber parts such as diaphragms and fuel hoses.
Therefore, to raise the fuel temperature, a water passage is provided in the fuel pressure regulator to allow
the engine coolant to warm the regulator.
DTC No.DTC Detecting ConditionTrouble Area
P1190After engine is warmed up, detection of pressure control
malfunction (2 trip detection logic)

Open or short in fuel shutoff valve circuit for fuel tank

Fuel shutoff valve for fuel tank

Open or short in fuel shutoff valve circuit for fuel pressure
regulator

Fuel shutoff valve for fuel pressure regulator

Fuel fuel pressure regulator

Open or short in fuel shutoff valve circuit for fuel delivery
pipe

Fuel shutoff valve for fuel delivery pipe

ECM
DI64X±01

A09426
Battery
EFI
AM2
1 2 3
3 1J
B2A
2J Instrument Panel J/B
1B 1W
37
15
IG Switch
1
B±RST Relay EFI Relay
5
6 3
11 410
4
5 4
5
A 2B STARTER
II23
B±W
II2
11
Starter
Park/Neutral
Position Switch
5 7
B±R Engine Room J/B No.2
2C
2F IGN
FL Block1
2D1
MAIN
W±B
10B
C
1
CIR
OPN
Relay
IGG±R
14
2L
E4FCECM
E01 1
S1S2
Engine Room R/B
No.1
2
J40
J/C
G±R
L±B
5 93
L±B
R
EB B±R
GR
W±R
B±W
BL
J/CB±R
J8
2K
J7
B
1 1 1
B 1K
1K
1K
8 76
EB1
4
J11
J/CF6 1
W±R
MAIN
FL2K
2
B±RB
B F41
GR
A
EB1
55
W±BW±B
GR
Fuel ShutOff Valve For
Pressure Regulator
Fuel ShutOff Valve
For Fuel TankFuel ShutOff Valve
For Delivery Pipe
ID1
7 J29
J/C
B
B±W
VCNG2VCNG3 4
E7
9
E7
13
E6 2
2J21
II39
II4
6 J19
J/C
B
B±G
21
21
L±B L±B
EC
L±B L±B
Y±G
W±B B±Y B±Y
BB±Y
P
± DIAGNOSTICSENGINE
DI±87
WIRING DIAGRAM

DI±88
± DIAGNOSTICSENGINE
INSPECTION PROCEDURE
TOYOTA hand±held tester:
1 Check fuel shutoff valve for delivery pipe.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the 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.
CHECK:
Check the operating sound of the fuel shutoff valve for delivery pipe for fuel tank when it is operated by the
TOYOTA hand±held tester.
HINT:
Use a sound scope or your finger to check the operating sound.
OK:
There is operating sound from the shutoff valve.
OK Go to step 9.
2 Check fuel shutoff valve for fuel pressure regulator and fuel shutoff valve for
fuel tank.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the 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.
CHECK:
Check the operating sound of the fuel shutoff valve for fuel pressure regulator and fuel shutoff valve for fuel
tank when it is operated by the TOYOTA hand±held tester.
HINT:
Fuel shutoff valve for fuel pressure regulator:
Use a sound scope or your finger to check the operating sound.
OK:
There is operating sound from the shutoff valve.
NG Fuel shutoff valve for fuel pressure regulator ...
Go to step 7.
NG Fuel shutoff valve for fuel tank ... Go to step 4.
NG

A09424
ON
VCNG2
(±)
(+) E01
A09425
ON
VCNG3
(±)(+) E01
DI±90
± DIAGNOSTICSENGINE
OK
7 Check voltage between terminals VCNG2 and E01 of ECM connectors.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals VCNG2 and E01 of the
ECM connectors.
OK:
Voltage: 9 ± 14 V
OK Check and replace ECM (See page IN±29).
NG
8 Check fuel shutoff valve for fuel pressure regulator (See page SF±30).
NG Replace fuel shutoff valve with fuel pressure
regulator.
OK
Check for open in harness and connector between circuit opening relay (Marking: CIR OPN) and
fuel shutoff valve for fuel pressure regulator, and fuel shutoff valve for fuel pressure regulator
and ECM (See page IN±29).
9 Check voltage between terminals VCNG3 and E01 of ECM connectors.
PREPARATION:
(a) Remove the glove compartment.
(b) Start the engine.
CHECK:
Measure the voltage between terminals VCNG3 and E01 of the
ECM connectors.
OK:
Voltage: 9 ± 14 V

A09424
ON
VCNG2
(±)
(+) E01
A09425
ON
VCNG3
(±)(+) E01
± DIAGNOSTICSENGINE
DI±93
7 Check voltage between terminals VCNG2 and E01 of ECM connectors.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals VCNG2 and E01 of the
ECM connectors.
OK:
Voltage: 9 ± 14 V
OK Check and replace ECM (See page IN±29).
NG
8 Check fuel shutoff valve for fuel pressure regulator (See page SF±30).
NG Replace fuel shutoff valve with fuel pressure
regulator.
OK
Check for open in harness and connector between circuit opening relay (Marking: CIR OPN) and
fuel shutoff valve for fuel pressure regulator, and fuel shutoff valve for fuel pressure regulator
and ECM (See page IN±29).
9 Check voltage between terminals VCNG3 and E01 of ECM connectors.
PREPARATION:
(a) Remove the glove compartment.
(b) Start the engine.
CHECK:
Measure the voltage between terminals VCNG3 and E01 of the
ECM connectors.
OK:
Voltage: 9 ± 14 V
OK Check and replace ECM (See page IN±29).

DI±98
± DIAGNOSTICSENGINE
DTC P1245 Fuel Fuel Shutoff Valve Circuit for Pressure
Regulator Malfunction
CIRCUIT DESCRIPTION
Refer to DTC P1190 on page DI±86.
DTC No.DTC Detecting ConditionTrouble Area
P1245Open in fuel shutoff valve circuit for fuel pressure regulator

Open or short in fuel shutoff valve circuit for fuel pressure
regulator

Fuel shutoff valve for fuel pressure regulator

ECM
WIRING DIAGRAM
Refer to DTC P1190 on page DI±86.
INSPECTION PROCEDURE
TOYOTA hand±held tester:
1 Check fuel shutoff valve circuit for fuel pressure regulator.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Turn the 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.
CHECK:
Check the operating sound of the fuel shutoff valve for the pressure regulator when it is operated by the TOY-
OTA hand±held tester.
HINT:
Use a sound scope or your finger to check the operating sound.
OK:
There is operating sound from the shutoff valve.
OK Go to step 4.
NG
2 Check for ECM power source circuit (See page DI±116).
NG Repair or replace.
OK
DI64Z±01

A09277
FC ON
(±) (+)
DI±100
± DIAGNOSTICSENGINE
6 Check fuel shutoff valve for fuel pressure regulator (See page SF±30).
NG Replace fuel shutoff valve for fuel pressure reg-
ulator.
OK
Check for open in harness and connector between circuit opening relay (Marking: CIR OPN) and
fuel shutoff valve for fuel pressure regulator, and fuel shutoff valve for fuel pressure regulator
and ECM (See page IN±29).
OBD II scan tool (excluding TOYOTA hand±held tester):
1 Check for ECM power source circuit (See page DI±116).
NG Repair or replace.
OK
2 Check fuel shutoff valve for fuel pressure regulator (See page SF±30).
NG Replace circuit opening relay.
OK
3 Check voltage between terminal FC of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Disconnect the E4 connector from the ECM.
(c) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal FC of the ECM connec-
tor and body ground.
OK:
Voltage 9 ± 14 V

A09424
ON
VCNG2
(±)
(+) E01
± DIAGNOSTICSENGINE
DI±101
OK Go to step 4.
NG
Check for open in harness and connector between EFI main relay (Marking: EFI) and circuit open-
ing relay (Marking: CIR OPN), and circuit opening relay and ECM (See page IN±29).
4 Check voltage between terminals VCNG2 and E01 of ECM connectors.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals VCNG2 and E01 of the
ECM connectors.
OK:
Voltage 9 ± 14 V
OK Check and replace ECM (See page IN±29).
NG
5 Check fuel shutoff valve for fuel pressure regulator (See page SF±30).
NG Replace fuel shutoff valve for fuel pressure reg-
ulator.
OK
Check for open in harness and connector between circuit opening relay (Marking: CIR OPN) and
fuel shutoff valve for fuel pressure regulator, and fuel shutoff valve for fuel pressure regulator
and ECM (See page IN±29).

A00309
ECM Fuel Pressure Sensor
for Fuel Pipe
1PCNG1VC
E2 Y
G±RE5
E7
E5 3
25 V
E1 1
5
9
BR
BE6653A03008A09254
ON
E2VC
(±) (+)
± DIAGNOSTICSENGINE
DI±123
Fuel Pressure Sensor Circuit for Fuel Pipe
CIRCUIT DESCRIPTION
Refer to DTC P0190 on page DI±56.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals VC and E2 of the ECM
connector.
OK:
Voltage: 4.5 ± 5.5 V
NG Check and replace ECM (See page IN±29).
OK
DI650±01

BE6653A09292A09419
E2 ONPCNG1
(±)
(+)
DI±124
± DIAGNOSTICSENGINE
2 Check voltage between terminals PCNG1 and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals PCNG1 and E2 of the
ECM connector.
OK:
Needle position of fuel level gaugeVoltage (V) at 20°C (68°F)
4/43.3
3/42.7
2/42.0
1/41.3
OK Check and replace ECM (See page IN±29).
NG
3 Check for open and short in harness and connector between fuel pressure sen-
sor for fuel pipe and ECM
(See page IN±29).
NG Repair or replace harness or connector.
OK
Replace fuel pressure sensor for fuel pipe
(See page SF±46).