EMISSION CONTROL TOYOTA CAMRY 1999 Service Owner's Manual

DI±332
± DIAGNOSTICSENGINE (1MZ±FE)
567 Author: Date:
WIRING DIAGRAM
Refer to DTC P0440 (Evaporative Emission Control Malfunction) on page DI±311.
INSPECTION PROCEDURE
HINT:

If DTCs P0441, P0446, P0450 or P0451 is output after DTC P0440, first troubleshoot DTCs 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±311, step 9).
NG Check and replace ECM (See page IN±31).
OK
2 Check voltage between terminals PTNK and E2 of ECM connectors
(See page DI±311, step 10).
OK Check and replace ECM (See page IN±31).
NG
3 Check for open and short in harness and connector between vapor pressure
sensor and ECM (See page IN±31).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.

DI02W±02
FI0534
S05335
TOYOTA hand±held tester
DLC3
± DIAGNOSTICSAUTOMATIC TRANSAXLE (A140E)
DI±389
624 Author: Date:
PRE±CHECK
1. DIAGNOSIS SYSTEM
(a) Description

When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect an OBD II scan tool complying
with SAE J1987 or TOYOTA hand±held tester to the
vehicle, and read off various data output from the
vehicle's ECM.
OBD II regulations require that the vehicle's on±
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the computer itself or
in drive system components which affect vehicle
emissions. In addition to the MIL lighting up when
a malfunction is detected, the applicable DTCs pre-
scribed by SAE J2012 are recorded in the ECM
memory (See page DI±16).
If the malfunction only occurs in 3 trips, the MIL goes
off but the DTCs remain recorded in the ECM
memory.

To check the DTCs, connect an OBD II scan tool or
TOYOTA hand±held tester to DLC3 on the vehicle.
The OBD II scan tool or TOYOTA hand±held tester
also enables you to erase the DTCs and check
freeze frame data and various forms of engine data
(For instruction book).
DTCs include SAE controlled codes and Manufac-
turer controlled codes.
SAE controlled codes must be set as the codes pre-
scribed by the SAE, while Manufacturer controlled
codes can be set freely by the manufacturer within
the prescribed limits.
(See DTC chart on page DI±401)

FI0534
DI02E±02
S05335
TOYOTA hand±held tester
DLC3
DI±438
± DIAGNOSTICSAUTOMATIC TRANSAXLE (A541E)
673 Author: Date:
PRE±CHECK
1. DIAGNOSIS SYSTEM
(a) Description

When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect to the vehicle an OBD II scan
tool complying with SAE J1987 or TOYOTA hand±
held tester, and read off various data output from
the vehicle's ECM.
OBD II regulations require that the vehicle's on±
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the computer itself or
in drive system components which affect vehicle
emissions. In addition to the MIL lighting up when
a malfunction is detected, the applicable DTCs pre-
scribed by SAE J2012 are recorded in the ECM
memory. (See page DI±211)
If the malfunction only occurs in 3 trips, the MIL goes
off but the DTCs remain recorded in the ECM
memory.

To check the DTCs, connect an OBD II scan tool or
TOYOTA hand±held tester to DLC3 on the vehicle.
The OBD II scan tool or TOYOTA hand±held tester
also enables you to erase the DTCs and check
freeze frame data and various forms of engine data
(For instruction book).
DTCs include SAE controlled codes and Manufac-
turer controlled codes.
SAE controlled codes must be set as prescribed by
the SAE, while Manufacturer controlled codes can
be set freely by the manufacturer within the pre-
scribed limits (See DTC chart on page DI±449).

DI64S±01
S05347
S05331
TOYOTA Hand±Held Tester
DLC3
± DIAGNOSTICSENGINE
DI±3
PRE±CHECK
1. DIAGNOSIS SYSTEM
(a) Description

When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect to the vehicle the OBD II scan
tool complying with SAE J1978 or TOYOTA hand±
held tester, and read off various data output from
the vehicle's ECM.

OBD II regulations require that the vehicle's on±
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the emission control
system/components or in the power train control
components which affect vehicle emissions, or a
malfunction in the computer. In addition to the MIL
lighting up when a malfunction is detected, the ap-
plicable Diagnostic Trouble Code (DTC) prescribed
by SAE J2012 are recorded in the ECM memory.
(See page DI±14)
If the malfunction does not reoccur in 3 consecutive trips, the
MIL goes off automarially but the DTCs remain recorded in the
ECM memory.

To check the DTCs, connect the OBD II scan tool or
TOYOTA hand±held tester to the Data Link Con-
nector 3 (DLC3) on the vehicle. The OBD II scan
tool or TOYOTA hand±held tester also enables you
to erase the DTCs and check freezed frame data
and various forms of engine data (For operating
instructions, see the OBD II scan tool's instruction
book.)
DTCs include SAE controlled codes and manufac-
turer controlled codes. SAE controlled codes must
be set as prescribed by the SAE, while manufactur-
er controlled codes can be set freely by the
manufacturer within the prescribed limits. (See DTC
chart on page DI±14)

P25430
ECM
Throttle Body
EGR
Vacuum
Modulator EGR Valve
VSV
Exhaust Gas Throttle
Valve
u
± DIAGNOSTICSENGINE
DI±63
DTC P0400 Exhaust Gas Recirculation Flow Malfunction
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combustion temperature and reduce
NOx emissions. The amount of EGR is regulated by the EGR vacuum modulator according to the engine
load.
If even one of the following conditions is fulfilled, the VSV is
turned ON by a signal from the ECM.
This results in atmospheric air acting on the EGR valve, closing
the EGR valve and shutting off the exhaust gas (EGR cut±off).
Under the following conditions, EGR is cut to maintain driveabil-
ity.

Before engine is warmed up.

During deceleration (throttle valve closed).

Light engine load (amount of intake air very small).

Engine idling.

Engine speed over 4,400 rpm.

High engine load (amount of intake air very large).
DTC No.DTC Detecting ConditionTrouble Area
P0400
After engine is warmed up, intake manifold absolute pressure
is larger than value calculated by ECM while EGR system is
ON (2 trip detection logic)

Vacuum or EGR hose is connected to wrong post

Open or short in VSV circuit for EGR

VSV for EGR

EGR system

EGR vacuum modulator

EGR valve

Manifold absolute pressure sensor

ECM
DI64W±01

FI0534
DI02W±05
S05335
Hand±held Tester
DLC3
± DIAGNOSTICSAUTOMATIC TRANSAXLE
DI±133
PRE±CHECK
1. DIAGNOSIS SYSTEM
(a) Description

When troubleshooting OBD II vehicles, the only dif-
ference from the usual troubleshooting procedure
is that you connect an OBD II scan tool complying
with SAE J1987 or hand±held tester to the vehicle,
and read off various data output from the vehicle's
ECM.
OBD II regulations require that the vehicle's on±
board computer lights up the Malfunction Indicator
Lamp (MIL) on the instrument panel when the com-
puter detects a malfunction in the computer itself or
in drive system components which affect vehicle
emissions. In addition to the MIL lighting up when
a malfunction is detected, the applicable DTCs pre-
scribed by SAE J2012 are recorded in the ECM
memory (See page DI±14).
If the malfunction only occurs in 3 trips, the MIL goes
off but the DTCs remain recorded in the ECM
memory.

To check the DTCs, connect an OBD II scan tool or
hand±held tester to DLC3 on the vehicle. The OBD
II scan tool or hand±held tester also enables you to
erase the DTCs and check freeze frame data and
various forms of engine data (For instruction book).
DTCs include SAE controlled codes and Manufac-
turer controlled codes.
SAE controlled codes must be set as the codes pre-
scribed by the SAE, while Manufacturer controlled
codes can be set freely by the manufacturer within
the prescribed limits (See DTC chart on page
DI±14)

EC039±05
± EMISSION CONTROL (5S±FE)EMISSION CONTROL SYSTEM
EC±1
1399 Author: Date:
EMISSION CONTROL SYSTEM
PURPOSE
The emission control systems are installed to reduce the amount of HC, CO and NOx exhausted from the
engine ((3), (4) and (5)), to prevent the atmospheric release of blow±by gas±containing HC (1) and evapo-
rated fuel containing HC being released from the fuel tank (2).
The function of each system is shown in the following table.
SystemAbbreviationFunction
(1) Positive Crankcase Ventilation
(2) Evaporative Emission Control
(3) Exhaust Gas Recirculation
(4) Three±Way Catalytic Converter
(5) Sequential Multiport Fuel Injection*PCV
EVAP
EGR
TWC
SFIReduces HC
Reduces evaporated HC
Reduces NOx
Reduces HC, CO and NOx
Injects a precisely timed, optimum amount of fuel for reduced
exhaust emissions
Remark: * For inspection and repair of the SFI system, refer to the SFI section in this manual.

EC03A±03
B06542
PCV Valve
VSV for EGR
Front TWC
(California)EGR Vacuum Modulator
EGR Valve
TWC (Except California)
Rear TWC (California)
VSV for EVAP
Vent Line
Charcoal Canister
Fuel Tank
EVAP Line
Air Drain Hose
Filler Pipe
Air Inlet LinePurge Line Cutoff Valve
Fill Check Valve
EVAP Service Port
Fuel Tank Cap
VSV for Vapor
Pressure Sensor Vapor Pressure Sensor
EC±2
± EMISSION CONTROL (5S±FE)PARTS LAYOUT AND SCHEMATIC DRAWING
1400 Author: Date:
PARTS LAYOUT AND SCHEMATIC DRAWING
LOCATION

EC03B±03
B06549
VSV for EGR Front TWC
(California)EGR Vacuum Modulator
EGR
Valve
TWC (Except California)
Rear TWC (California)VSV
for EVAP
Vent Line
Charcoal CanisterFuel Tank EVAP Line
Air Drain HoseFiller Pipe
Air Inlet Line Purge LineEVAP Service Port
Fuel Tank Cap
Vapor
Pressure
SensorVSV for Vapor
Pressure Sensor
± EMISSION CONTROL (5S±FE)PARTS LAYOUT AND SCHEMATIC DRAWING
EC±3
1401 Author: Date:
DRAWING

EC03C±05
B01531
Clean Hose
Cylinder Head Side
B01532
Clean Hose
Intake
Manifold
Side
S01846
EC±4± EMISSION CONTROL (5S±FE)POSITIVE CRANKCASE VENTILATION (PCV)
SYSTEM
1402 Author: Date:
POSITIVE CRANKCASE
VENTILATION (PCV) SYSTEM
INSPECTION
1. INSPECT PCV VALVE
(a) Remove the PCV valve.
(b) Install a clean hose to the PCV valve.
(c) Inspect the PCV valve operation.
(1) Blow air into the cylinder head side, and check that
air passes through easily.
CAUTION:
Do not suck air through the valve. Petroleum substances
inside the valve are harmful.
(2) Blow air into the intake manifold side, and check
that air passes through with difficulty.
If operation is not as specified, replace the PCV valve.
(d) Remove the clean hose from the PCV valve.
(e) Reinstall the PCV valve.
2. INSPECT HOSES, CONNECTIONS AND GASKETS
Visually check for cracks, leaks or damage.