fuel pressure TOYOTA CAMRY 1999 Service Workshop Manual

± 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

P20186
± DIAGNOSTICSENGINE (1MZ±FE)
DI±205
440 Author: Date:
7 Check fuel pressure.
PREPARATION:
(a) Be sure that enough fuel is in the tank.
(b) Connect the TOYOTA hand±held tester to the DLC3.
(c) Turn the ignition switch ON and push the TOYOTA hand±
held tester main switch ON.
(d) Use ACTIVE TEST mode to operate the fuel pump.
(e) If you have no TOYOTA hand±held tester, connect the
positive (+) and negative (±) leads from the battery to the
fuel pump connector (See page SF±6).
CHECK:
Check that the pulsation damper screw rises up when the fuel
pump operates.
NG Proceed to page SF±6 and continue to
troubleshoot.
OK

± DIAGNOSTICSENGINE (1MZ±FE)
DI±209
444 Author: Date:
(b) TOYOTA Enhanced Signals.
TOYOTA hand±held tester displayMeasurement ItemNormal Condition*
MISFIRE RPMEngine RPM for first misfire rangeMisfire 0: 0 rpm
MISFIRE LOADEngine load for first misfire rangeMisfire 0: 0 g/r
INJECTORFuel injection time for cylinder No.1Idling: 1.6 ~ 2.9 ms
IAC DUTY RATIOIntake Air Control Valve Duty Ratio
Opening ratio rotary solenoid type IAC valveIdling: 27 ~ 47 %
STARTER SIGStarter SignalCranking: ON
CTP SIGClosed Throttle Position SignalThrottle Fully Closed: ON
A/C SIGA/C Switch SignalA/C ON: ON
PNP SWPark/Neutral Position Switch SignalP or N position: ON
ELCTRCL LOAD SIGElectrical Load SignalDefogger switch ON: ON
STOP LIGHT SWStop Light Switch SignalStop light switch ON: ON
PS OIL PRESS SWPower Steering Oil Pressure Switch SignalTurn steering wheel: ON
FC IDLFuel Cut Idle: Fuel cut when throttle valve fully
closed, during decelerationFuel cut operating: ON
FC TAUFuel Cut TAU: Fuel cut during very light loadFuel cut operating: ON
CYL#1 ~ CYL#6Abnormal revolution variation for each cylinder0%
IGNITIONTotal number of ignition for every 1,000 revolu-
tions0 ~ 3,000
EGRT GASEGR Gas Temperature Sensor Value
EGR not operating:
Temperature between intake air temp. and
engine coolant temp.
INTAKE CTRL VSVIntake Air Control Valve VSV SignalVSV operating: ON
EGR SYSTEMEGR system operating conditionIdling: OFF
A/C CUT SIGA/C Cut SignalA/C S/W OFF: ON
FUEL PUMPFuel Pump SignalIdling: ON
EVAP (PURGE) VSVEVAP VSV SignalVSV operating: Above 30%
VAPOR PRESS VSVVapor Pressure VSV SignalVSV operating: ON (TANK)
*: If no conditions are specifically stated for ºldlingº, it means the shift lever is at N or P position, the A/C switch
is OFF and all accessory switches are OFF.

DI±212
± DIAGNOSTICSENGINE (1MZ±FE)
447 Author: Date:
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
*2
P0133
(DI±259)
Heated Oxygen Sensor Circuit
Slow Response
(Bank 1 Sensor 1)Heated oxygen sensor
Fuel trim malfunction
*2
P0135
(DI±263)
Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 1)Open or short in heater circuit of heated oxygen sensor
Heated oxygen sensor heater
ECM

P0136
(DI±265)Heated Oxygen Sensor Circuit
Malfunction
(Bank 1 Sensor 2)
Heated oxygen sensor
P0141
(DI±263)Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 2)
Same as DTC No. P0135*1
*3
P0150
(DI±255)
Heated Oxygen Sensor
Circuit Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P0130*1
*3
P0153
(DI±259)
Heated Oxygen Sensor
Circuit Slow Response
(Bank 2 Sensor 1)Same as DTC No. P0133
Fuel trim malfunction*1
*3
P0155
(DI±263)Heated Oxygen Sensor
Circuit Malfunction
(Bank 2 Sensor 1)
Same as DTC No. P0135*1
*3
P0171
(DI±272)System too Lean
(Fuel Trim)
(Except California Spec.)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Heated oxygen sensor (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
*1
*3
P0172
(DI±272)System too Rich
(Fuel Trim)
(Except California Spec.)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensor (bank 1, 2 sensor 1) malfunction
Mass air flow meter
Engine coolant temp. sensor
Gas leakage on exhaust system
*1
*4
P0171
(DI±267)System too Lean
(Fuel Trim)
(Only for California Spec.)
Air intake (hose loose)
Fuel line pressure
Injector blockage
Mass air flow meter
Engine coolant temp. sensor
A/F sensor (bank 1, 2 sensor 1)
Gas leakage on exhaust system
*1
*4
P0172
(DI±267)System too rich
(Fuel Trim)
(Only for California Spec.)
Fuel line pressure
Injector leak, blockage
Heated oxygen sensor malfunction
Mass air flow meter
Engine coolant temp. sensor
A/F sensor (bank 1, 2 sensor 1)
Gas leakage on exhaust system
*1
*1: MIL lights up
*2: MIL light up or blinking
*3: Except California specification vehicles
*4: Only for California specification vehicle

± DIAGNOSTICSENGINE (1MZ±FE)
DI±213
448 Author: Date:
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
P0300
(DI±276)Random/Multiple Cylinder
Misfire DetectedIgnition system
Injector
Fuel line pressure
EGR
P0301
P0302
P0303
P0304
P0305
P0306
(DI±276)Misfire Detected
± Cylinder 1
± Cylinder 2
± Cylinder 3
± Cylinder 4
± Cylinder 5
± Cylinder 6
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Mass air flow meter
Engine coolant temp. sensor
Open or short engine wire
Connector connection
ECM
*2
P0325
(DI±283)Knock Sensor 1 Circuit
MalfunctionOpen or short in knock sensor 1 circuit
Knock sensor 1 (looseness)
ECM
*1
P0330
(DI±283)Knock Sensor 2 Circuit
MalfunctionOpen or short in knock sensor 2 circuit
Knock sensor 2 (looseness)
ECM
*1
P0335
(DI±287)Crankshaft Position Sensor
ºAº Circuit Malfunction
Open or short in crankshaft position sensor circuit
Crankshaft position sensor
Starter
ECM
*1
P0340
(DI±290)Camshaft Position Sensor
Circuit Malfunction
Open or short in camshaft position sensor circuit
Camshaft position sensor
Starter
ECM
*1
P0401
(DI±292)Exhaust Gas Recirculation
Flow Insufficient Detected
EGR valve (stuck closed)
Open or short in EGR gas temp. sensor circuit
EGR gas temp. sensor
Open in VSV circuit for EGR
VSV for EGR
Vacuum control valve
Vacuum hose disconnected or blocked
ECM
*1
P0402
(DI±302)Exhaust Gas Recirculation
Flow Excessive Detected
EGR valve stuck open
VSV for EGR open malfunction
Short in VSV circuit for EGR
Open or short in EGR valve position sensor circuit
EGR valve position sensor
ECM
*1
*3
P0420
(DI±305)Catalyst System Efficiency
Below Threshold
(Except California Spec.)Three±way catalytic converter
Open or short in heated oxygen sensor circuit
Heated oxygen sensor
*2
*4
P0420
(DI±308)Catalyst System Efficiency
Below Threshold
(Only for California Spec.)
Three±way catalytic converter
Open or short in heated oxygen sensor (bank 1, sensor 2)
circuit
Heated oxygen sensor (bank 1, sensor 2)
Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
*2
*1: MIL lights up
*2: MIL lights up on U.S.A and Canadian specification vehicles
*3: Except California specification vehicles
*4: Only for California specification vehicle