fuel pressure TOYOTA CAMRY 1999 Service Manual PDF

DI±214
± DIAGNOSTICSENGINE (1MZ±FE)
449 Author: Date:
DTC No.
(See Page)Detection ItemTrouble AreaMIL*Memory
P0440
(DI±311)Evaporative Emission Control
System Malfunction
Vapor pressure sensor
Fuel tank cap incorrectly installed
Fuel tank cap cracked or damaged
Vacuum hose cracked, holed, blocked, damaged or
disconnected ((1) or (2) in fig. 1)
Hose or tube cracked, holed, damaged or loose seal
((3) in fig. 1)
Fuel tank cracked, holed or damaged
Charcoal canister cracked, holed or damaged
Fuel tank over fill check valve cracked or damaged
*1
P0441
(DI±318)Evaporative Emission Control
System Incorrect Purge Flow
Open or short in VSV circuit for EVAP
Open or short in VSV circuit for vapor pressure sensor
Open or short in vapor pressure sensor circuit
VSV for EVAP
VSV for vapor pressure sensor
Vapor pressure sensor
Vacuum hose cracks, holed blocked, damaged or
disconnected ((1), (4), (5), (6) and (7) in fig.1)
Charcoal canister cracks, holed or damaged
Fuel tank over fill check valve cracked or damaged

P0446
(DI±318)Evaporative Emission Control
System Vent Control
Malfunction
Open or short in VSV circuit for EVAP
Open or short in VSV circuit for vapor pressure sensor
Open or short in vapor pressure sensor circuit
VSV for EVAP
VSV for vapor pressure sensor
Vapor pressure sensor
Vacuum hose cracks, holed blocked, damaged or
disconnected ((1), (4), (5), (6) and (7) in fig.1)
Charcoal canister cracks, holed or damaged
Fuel tank over fill check valve cracked or damaged

P0450
(DI±331)Evaporative Emission Control
System Pressure Sensor
MalfunctionOpen or short in vapor pressure sensor circuit
Vapor pressure sensor
ECM

P0451
(DI±331)Evaporative Emission Control
System Pressure Sensor
Range/PerformanceOpen or short in vapor pressure sensor circuit
Vapor pressure sensor
ECM

P0500
(DI±333)Vehicle Speed Sensor
Malfunction
Open or short in speed sensor circuit
Vehicle speed sensor
Combination meter
ECM

P0505
(DI±336)Idle Control System
Malfunction
IAC valve is stuck or closed
Open or short in IAC valve circuit
Open or short in A/C signal circuit
Air intake (hose loose)

*: 


MIL lights up

± DIAGNOSTICSENGINE (1MZ±FE)
DI±247
482 Author: Date:
4 Check whether misfire is occurred or not by monitoring DTC and data list.
NG Perform troubleshooting for misfire
(See page DI±351).
OK
5 Check air induction system (See page SF±1).
NG Repair or replace.
OK
6 Check EGR system (See page EC±11).
NG Replace 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
8 Check injector injection (See page SF±25)
NG Replace injector.
OK

± DIAGNOSTICSENGINE (1MZ±FE)
DI±253
488 Author: Date:
4 Check resistance of A/F sensor heaters (bank1, 2 sensor1) (See page SF±68).
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±11).
NG Replace EGR system.
OK
7 Check fuel pressure (See page SF±21).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF±1).
OK
8 Check injector injection (See page SF±25).
NG Replace injector.
OK

± DIAGNOSTICSENGINE (1MZ±FE)
DI±257
492 Author: Date:
3 Check for open and short in harness and connector between ECM and heated
oxygen sensors (bank1, 2 sensor1) (See page IN±31).
NG Repair or replace harness or connector.
OK
4 Check air induction system (See page SF±1).
NG Repair or replace.
OK
5 Check EGR system (See page EC±11).
NG Replace EGR system.
OK
6 Check fuel pressure (See page SF±6).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF±1).
OK

± DIAGNOSTICSENGINE (1MZ±FE)
DI±261
496 Author: Date:
5 Check EGR system (See page EC±11).
NG Replace EGR system.
OK
6 Check fuel pressure (See page SF±1).
NG Check and repair fuel pump, fuel pipe line and
filter (See page SF±1).
OK
7 Check injector injection (See page SF±25).
NG Replace injector.
OK
Replace heated oxygen sensors
(bank1, 2 sensor1).
8 Perform confirmation driving pattern (See page DI±255).
Go

± DIAGNOSTICSENGINE (1MZ±FE)
DI±267
502 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Only for California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Only for California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short±term fuel trim and long±term fuel trim.
Short±term fuel trim is the short±term fuel compensation used to maintain the air±fuel ratio at its ideal
theoretical value.
The signal from the A/F sensor is approximately proportional to the existing air±fuel ratio, and ECM compar-
ing it with the ideal theoretical value, the ECM reduces fuel volume immediately if the air±fuel ratio is rich
and increases fuel volume if it is lean.
Long±term fuel trim compensates the deviation from the central value of the short±term fuel trim stored up
by each engine tolerance, and the deviation from the central value due to the passage of time and changes
of using environment.
If both the short±term fuel trim and long±term fuel trim exceed a certain value, it is detected as a malfunction
and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on RICH side
(2 trip detection logic)

Gas leakage on exhaust system

Air intake (hose loose)

Fuel line pressure

Injector blockage

Mass air flow meter

Engine coolant temp. sensor

A/F sensors (bank 1, 2 sensor 1)
P0172
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on LEAN side
(2 trip detection logic)

Gas leakage on exhaust system

Fuel line pressure

Injector leak, blockage

Mass air flow meter

Engine coolant temp. sensor

A/F sensors (bank 1, 2 sensor 1)
DI07R±05

± DIAGNOSTICSENGINE (1MZ±FE)
DI±269
504 Author: Date:
4 Check for spark and ignition (See page IG±1).
NG Repair or replace.
OK
5 Check fuel pressure (See page SF±21).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF±1).
OK
6 Check gas leakage on exhaust system.
NG Repair or replace.
OK

DI±272
± DIAGNOSTICSENGINE (1MZ±FE)
507 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Except California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Except California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short±term fuel trim and long±term fuel trim.
Short±term fuel trim 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.
Long±term fuel trim is overall fuel compensation carried out long±term to compensate for continual deviation
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
detected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on RICH side
(2 trip detection logic)

Air intake (hose loose)

Fuel line pressure

Injector blockage

Heated oxygen sensors (bank 1, 2 sensor 1) malfunction

Mass air flow meter

Engine coolant temp. sensor

Gas leakage on exhaust system
P0172
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on LEAN side
(2 trip detection logic)

Fuel line pressure

Injector leak, blockage

Heated oxygen sensors (bank 1, 2 sensor 1) malfunction

Mass air flow meter

Engine coolant temp. sensor

Gas leakage on exhaust system
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 % (80°C (176°F)
or more), the system is functioning normally.
INSPECTION PROCEDURE
HINT:
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.
DI4DR±01

± DIAGNOSTICSENGINE (1MZ±FE)
DI±273
508 Author: Date:
1 Check air induction system (See page SF±1).
NG Repair or replace.
OK
2 Check injector injection (See page SF±21).
NG Replace injector.
OK
3 Check mass air flow meter and engine coolant temp. sensor
(See pages SF±35 and SF±63).
NG Repair or replace.
OK
4 Check for spark and ignition (See page IG±1).
NG Repair or replace.
OK
5 Check fuel pressure (See page SF±6).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter.
OK

DI±276
± DIAGNOSTICSENGINE (1MZ±FE)
511 Author: Date:
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 any
particular 200 or 1,000 revolutions
Ignition system

Injector

Fuel line pressure
P0301
P0302
P0303For any particular 200 revolutions for engine, misfiring is de-
tected which can cause catalyst overheating
(This causes MIL to blink)

EGR

Compression pressure

Valve clearance not to specification

Valve timing

Mass air flow meterP0303
P0304
P0305
P0306For any particular 1,000 revolutions of engine, misfiring is de-
tected which causes a deterioration in emission
(2 trip detection logic)

Mass air flow meter

Engine coolant temp. sensor

Open or short in engine wire

Connector connection

ECM
DI07S±07