1999 TOYOTA CAMRY fuel pressure

A03018A03422
ON EngineStart
Stop
VSV for Vapor
Pressure
Sensor
OFFOFF
ON
VSV for
EVAP
5 sec. 5 sec.
PTNK
(+)E2
(±) w/o Immobiliser
w/ Immobiliser
PTNK (+) E2(±)
DI±136
± DIAGNOSTICSENGINE (5S±FE)
371 Author: Date:
14 Check vacuum hoses between charcoal canister and VSV for vapor pressure
sensor, and vapor pressure sensor and VSV for vapor pressure sensor.
CHECK:
(a) Check that the vacuum hose is connected correctly.
(b) Check the vacuum hose for looseness and disconnection.
(c) Check the vacuum hose for cracks, hole, damage and blockage.
NG Repair or replace.
OK
15 Check the charcoal canister.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Connect the TOYOTA hand±held tester to the DLC3.
(c) Remove the fuel tank cap.
(d) Disconnect the VSV connector for the vapor pressure
sensor.
(e) Select the ACTIVE TEST mode on the TOYOTA hand±
held tester.
(f) Start the engine.
(g) The VSV for the EVAP is ON by the TOYOTA hand±held
tester and remains on for 5 sec.
CHECK:
Measure voltage between terminals PTNK and E2 of the ECM
connector 5 sec. after switching the VSV for the EVAP from ON
to OFF.
OK:
Voltage: 2.5 V or less
NG Replace charcoal canister.
OK

± DIAGNOSTICSENGINE (5S±FE)
DI±137
372 Author: Date:
16 Remove charcoal canister and check it (See page EC±5)
NG Replace charcoal canister.
OK
17 Check fuel tank over fill check valve (See page EC±6).
NG Replace fuel tank over fill check valve or fuel
tank.
OK
Check and replace ECM (See page IN±31).
OBD II scan tool (excluding TOYOTA hand±held tester):
HINT:
If DTC P0441 (Evaporative Emission Control System Incorrect Purge Flow), P0446 (Evaporative Emission
Control System Vent Control Malfunction) or P0450 (Evaporative Emission Control System Pressure Sensor
Malfunction) is output after DTC P0440 (Evaporative Emission Control System Malfunction), first trouble-
shoot DTC P0441, P0446 or P0450. If no malfunction is detected, troubleshoot DTC P0440 next.
1 Check VSV connector for EVAP, VSV connector for vapor pressure sensor and
vapor pressure sensor connector for looseness and disconnection.
NG Repair or connect VSV or sensor connector.
OK

± DIAGNOSTICSENGINE (5S±FE)
DI±141
376 Author: Date:
10 Check operation of VSV for vapor pressure sensor (See page SF±47).
NG Go to step 11.
OK
Replace VSV and clean vacuum hoses between charcoal canister and VSV for vapor pressure
sensor, and VSV for vapor pressure sensor and vapor pressure sensor, and then check the char-
coal canister.
11 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for vapor pressure sensor, and VSV for vapor pressure
sensor and ECM (See page IN±31).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±31).
12 Check fuel tank over fill check valve (See page EC±6).
NG Replace fuel tank over fill check valve or fuel
tank.
OK
Check and replace charcoal canister
(See page EC±6).

A06551
VSV for
EVAP
Charcoal Canister
Fuel Tank ECM
Vapor Pressure
Sensor
VSV for Vapor
Pressure Sensor
Fuel Tank Over
Fill Check Valve
DI±142
± DIAGNOSTICSENGINE (5S±FE)
377 Author: Date:
DTC P0450 Evaporative Emission Control System
Pressure Sensor Malfunction
DTC P0451 Evaporative Emission Control System
Pressure Sensor Range/Performance
CIRCUIT DESCRIPTION
The vapor pressure sensor and VSV for vapor pressure sensor are used to detect abnormalities in the evap-
orative emission control system.
The ECM decides whether there is an abnormality in the evaporative emission control system based on the
vapor pressure sensor signal.
DTC P0450 is recorded by the ECM when the vapor pressure sensor malfunction.
DI1K0±04

± DIAGNOSTICSENGINE (5S±FE)
DI±143
378 Author: Date:
DTC No.DTC Detecting ConditionTrouble Area
P0450
10 seconds or more after engine starting codition (a) or (b)
continues for 7 seconds or more:
(2 trip detection logic)
(a) vapor pressure sensor value < ±4 kpa (±30 mmHg,
±1.0 in.Hg)
(b) Vapor pressure sensor value
2.1 kpa (±15 mmHg,
0.4 in.Hg)

Open or short in vapor pressure sensor circuit

Vapor pressure sensor

ECM
F l t k fill h k l k d d d
P0451
Vapor pressure sensor output extremely changes under condi-
tions of (a), (b) and (c):
(2 trip detection logic)
(a) Vehicle speed: 0 km/h (0 mph)
(b) Engine speed: idling
(c) VSV for vapor pressure sensor is ON
Fuel tank over fill check valve cracked or damaged.
WIRING DIAGRAM
Refer to DTC P0440 (Evaporative Emission Control System Malfunction) on page DI±122.
INSPECTION PROCEDURE
HINT:

If DTC P0441 (Evaporative Emission Control System Incorrect Purge Flow), P0446 (Evaporative
Emission Control System Vent Control Malfunction), P0450 (Evaporative Emission Control System
Pressure Sensor Malfunction) or P0451 is output after DTC P0440 (Evaporative Emission Control Sys-
tem Malfunction), first troubleshoot DTC P0441, P0446, P0450 or P0451. If no malfunction is detected,
troubleshoot DTC P0440 next.

Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected, when troubleshooting it is useful for
determining whether the vehicle was running or stopped, the engine warmed up or not, the air±fuel
ratio lean or rich, etc. at the time of the malfunction.

When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
VSV for EVAP, charcoal canister and vapor pressure sensor.
1 Check voltage between terminals VC and E2 of ECM connector
(See page DI±122, step 9).
NG Check and replace ECM (See page IN±31).
OK

± DIAGNOSTICSENGINE (5S±FE)
DI±155
390 Author: Date:
4 Check resistance of A/F sensor heater (See page SF±59).
NG Replace A/F sensor.
OK
5 Check air induction system (See page SF±1).
NG Repair or replace.
OK
6 Check EGR system (See page EC±12).
NG Repair EGR system.
OK
7 Check fuel pressure (See page SF±6).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF±1).
OK

± DIAGNOSTICSENGINE (5S±FE)
DI±159
394 Author: Date:
4 Check resistance of A/F sensor heater (See page SF±59).
NG Replace A/F sensor.
OK
5 Check air induction system (See page SF±1).
NG Repair or replace.
OK
6 Check EGR system (See page EC±12).
NG Repair EGR system.
OK
7 Check fuel pressure (See page SF±6).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF±1).
OK

A03030A03451
ON
FC
OFFON
Fuel Inlet Hose
FC
OFF
ON w/o Immobiliser
w/ Immobiliser
± DIAGNOSTICSENGINE (5S±FE)
DI±187
422 Author: Date:
6 Check for open in harness and connector between circuit opening relay (Mark-
ing: CIR OPN) and fuel pump, and fuel pump and body ground
(See page IN±31).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±31).
OBD II scan tool (excluding TOYOTA hand±held tester):
1 Check operation of fuel pump.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Turn the ignition switch ON.
CHECK:
(a) Connect between terminal FC of the ECM connector and
body ground.
(b) Check for fuel pressure in the fuel inlet hose when it is
pinched off.
OK:
There is pressure in fuel inlet hose.
HINT:
At this time, you will hear a fuel return flowing noise.
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI±28).
NG