1999 TOYOTA CAMRY fuel type

EVAP SYSTEM OPERATION INFORMATION ± EG005-01 April 27, 2001
Page 4 of 14
Vapor Purge Flow P0441
The EVAP monitor is designed to detect:
Restricted vapor purge flow when the
purge VSV is open
Inappropriate vapor purge flow when
the purge VSV is closed
Under normal purge conditions, pressure
pulsations generated by the cycling of the
purge VSV are present in the canister
and detected by the Vapor Pressure
sensor.
Three±Way VSV P0446
The three±way VSV is connected to the Vapor Pressure sensor, canister, and fuel tank.
This VSV allows the Vapor Pressure sensor to detect either canister or tank pressure.
There are two modes the ECM can use to determine if the three±way VSV is
malfunctioning. The three±way VSV is judged to be normal if there is pressure difference
between the tank and canister when the three±way VSV is switched to look at the
charcoal canister and fuel tank side of system.
If there isn't any pressure difference between the fuel tank and canister, the ECM looks
for the following conditions:
During purging, pressure pulsations generated by the purge VSV are not present in
the canister as detected by Vapor Pressure sensor, the three±way VSV is judged to
be defective.
If there are pressure pulsations detected by the Vapor Pressure sensor present in the
fuel tank, the three±way VSV is judged to be defective.
Late Type (Intrusive) EVAP System Overview
The Late Type EVAP System, also known as the Intrusive type, was developed to meet
the very stringent, mandated standard of detecting a hole 0.020 inch (0.5 mm). This
system uses many of the same components as the early type EVAP system. Purge,
vacuum relief, pressure relief, and ORVR operations are identical to the early type. Refer
to the Applicable Vehicles chart for applicability information.
The following changes were made to the Late Type EVAP System:
Vapor pressure sensor connected to the fuel tank.
Bypass VSV in the place of the three way VSV.
Canister Closed Valve (CCV) on the air inlet line.Early Type
System
Description
(Continued)
Figure 5. Flow During Purge Operation
Late Type
System
Description

EVAP SYSTEM OPERATION INFORMATION ± EG005-01 April 27, 2001
Page 5 of 14
Late Type (Intrusive EVAP System) (Except ECHO)
Onboard Recovery Valve
(Fill Check Valve)Vapor
Pressure
SensorVacuum
Check
ValveTank Valve
AssemblyTank
Pressure
Valve
Canister
To
Manifold
Vacuum
Purge
VSV
Filtered
Air
Air Drain Valve
Air Valve AssemblyAir Inlet ValveCanister
Closed Valve
Bypass
VSVAir
Inlet LineService
Port
Tank Side
The bypass VSV and the fill check valve
assembly isolates the tank pressure side
from the canister side (see Figure 1).
Canister Side
The bypass VSV and the Fill Check valve
also isolate the canister side from the
tank side (see Figure 2).
Late Type
System
Description
(Continued)
Except ECHO
Figure 1. Fuel Tank Side of System
Except ECHO
Figure 2. Canister Side of System

EVAP SYSTEM OPERATION INFORMATION ± EG005-01 April 27, 2001
Page 7 of 14
ECHO Monitor Sequence
CCV Open
Purge
ClosedOpenClosed
Purge ClosedOpen Open
Cold Start ECT/IAT
Near Same TempNegative
Pressure
(Vacuum)
OccursTank &
Canister
Leak CheckCCV
Testing Vapor
Pressure
Sensor
Signal
Monitor Operation
The monitor sequence begins with a cold
engine start. The IAT and ECT sensors
must have approximately the same
temperature reading.
The ECM is constantly monitoring fuel
tank pressure. As the temperature of the
fuel increases, pressure slowly rises.
The ECM will purge the charcoal canister
at the appropriate time (see Figure 1).
With bypass VSV closed, pressure will
continue to rise in fuel tank.
Late Type
System
Monitor
Sequence
(Continued)
Except ECHO
Figure 1. Canister Purge
ECHO
Figure 1. Canister Purge

EVAP SYSTEM OPERATION INFORMATION ± EG005-01 April 27, 2001
Page 9 of 14
Vent Control, CCV Operation P0446
This stage checks the CCV and vent (air
inlet side) operation. When the vapor
pressure rises to a specified point, the
ECM opens the CCV. Pressure will
increase rapidly because of the air
allowed into the system. No increase or
an increase below specified rate of
pressure increase indicates a restriction
on the air inlet side (see Figure 4).
Bypass VSV Operation P0446
In the next stage, the ECM closes the
bypass VSV. This action blocks air
entering the tank side of the system. The
pressure rise on the fuel tank side is no
longer as great. If there was no change in
pressure, the ECM will conclude the
bypass VSV did not close (see Figure 5).Late Type
System
Monitor
Sequence
(Continued)Except ECHO
Figure 4. CCV Opens
ECHO
Figure 4. CCV Opens
Except ECHO
Figure 5. Bypass VSV Closes

EVAP SYSTEM OPERATION INFORMATION ± EG005-01 April 27, 2001
Page 11 of 14
Diagnostic Process Flow Chart
(Continued on following page)
PRELIMINARY CHECK
Fuel level should be between
1/4 and 3/4
Visually inspect for presence
of Fuel/Gas Cap
DO NOT TIGHTEN OR REMOVE!
PRESSURIZE EVAP SYSTEM (System Integrity Check)
This test checks for leaks in the canister and fuel tank sides. The CCV and Air Inlet Lines will be checked
separately.
A) Clamp the air drain hose on the charcoal canister with the supplied hose pliers from the EVAP System
Pressure Test Kit.
B) Locate the vapor pressure sensor. If the vapor pressure sensor has two hoses connected to it,
disconnect the hose between the air drain hose fitting at the vapor pressure sensor and plug the hose.
C) Connect the pressure supply hose from the Pressure Test Kit to the Green EVAP System Service Port
located on the EVAP Purge VSV line in the engine compartment.
D) Using the directions on the inside of the EVAP System Pressure Test Kit lid, pressurize the EVAP
system. Once pressurized, turn off the pump and seal the system (Pressure Hold Switch to ªClosedº
and Vent Switch to ªClosed).
E) After 30 seconds, note the pump pressure gauge reading and the Scan Tool vapor pressure
sensor reading.
F) Compare the readings to one of the four conditions listed below and proceed as directed.
DO NOT PROCEED! NG
OK
SCAN TOOL SETUP
A) Connect Scan Tool to DLC3 on vehicle.
B) Go to the SETUP menu and select UNIT CONVERSION.
C) Under VAPOR PRESSURE, Select ABS for absolute pressure, and mmHg for millimeters of mercury.
This is to match the Repair Manual specifications.
D) Go back to FUNCTION SELECT menu and select ENHANCED OBD II.
E) Select NORMAL MODE. Then select CURRENT DATA and USER SELECT.
F) Using the arrow key, select VAPOR PRESS from the DATA LIST and select YES.
G) Press ENTER. You will now be able to monitor the Vapor Pressure Sensor reading.
START
If vehicle is ECHO, go directly to ªECHO Canister and Tank Leak Checkº on page 14.
If vehicle is not ECHO, follow the flow chart below.
Diagnostic
Tips for Late
Type EVAP
System
(Continued)

EVAP SYSTEM OPERATION INFORMATION ± EG005-01 April 27, 2001
Page 12 of 14
Pump pressure
gauge and vapor
pressure above
atmospheric
pressure (above 762
mmHg). No leak in
canister or tank.Pump pressure
gauge zero, vapor
pressure above
atmospheric
pressure (above 762
mmHg). Leak is on
canister side of
system.Pump pressure
gauge is above
atmospheric
pressure (above
zero), vapor
pressure is at
762 mmHg. Leak is
on the fuel tank side
of system.Pump pressure
gauge at zero,
vapor pressure is
at 762 mmHg. The
leak(s) is/are on the
canister and tank
sides or a leak at a
point common to
both sides of system.
Remove hose pliers
from the air drain
hose on the charcoal
canister before
proceeding with
additional checks.Remove hose pliers
from the air drain
hose on the charcoal
canister before
proceeding with
additional checks.Remove hose pliers
from the air drain
hose on the charcoal
canister before
proceeding with
additional checks.
Go to CCV/Air Inlet
Line Check.Go to ªCanister Leak
Check.º Diagram on
page 13.Go to ªFuel Tank
Leak Check.º
Diagram on page 13.Go to ªFuel Tank
Leak Check.º
Diagram on page 13.
Remove hose pliers
from the air drain
hose on the charcoal
canister before
proceeding with
additional checks.
Go to ªReturn Vehicle to Serviceº on page 14.
CCV and Air Inlet Line Check. (Except ECHO)
A) Disconnect the air inlet line from the charcoal canister.
B) Using the supplied step±down brass adapter (or equivalent) connect the Pressure Supply Hose to
the air inlet line.
C) Using the Scan Tool Active Test, turn on the CCV. This will close the CCV.
D) Pressurize the line. Once pressurized, turn off the pump and seal the line (Pressure Hold Switch to
ªClosedº and Vent Switch to ªClosedº). Pressure should hold. If not, check CCV and connections.
E) Next, using the Scan Tool, turn off the CCV. This will open the CCV. The pressure should decrease.
If not, check the CCV and connections.
F) After completing the test, reconnect air inlet line to charcoal canister. Diagnostic Process Flow Chart (Continued)
(Continued from previous page)
Diagnostic
Tips for Late
Type EVAP
System
(Continued)

EVAP SYSTEM OPERATION INFORMATION ± EG005-01 April 27, 2001
Page 13 of 14
Disconnect
EVAP Hose Here
A. Using the supplied brass step±down adapter, disconnect the EVAP hose from
the charcoal canister side as indicated above. Connect Pressure Supply hose
from Pressure Test Kit to the EVAP hose and pressurize the fuel tank to
30 mmHg (4 kPa / 0.58 psi).
B. Check that the internal pressure of the tank will hold for 1 minute. Check shaded
areas for leaks (soapy water can be used for leak detection). If pressure holds, then
perform the Canister Leak Check.
C. When done, reconnect the EVAP line hose to the charcoal canister. Fuel Tank Leak Check (Except ECHO)
Canister Leak Check (Except ECHO)
A. Connect the Pressure Supply hose from the Pressure Test Kit to the Green EVAP
System Service Port located on the EVAP Purge VSV line in the engine compartment.
B. Using the directions on the inside of the EVAP System Pressure Test Kit lid,
pressurize the EVAP system. Once pressurized, turn off the pump and seal the system
(Pressure Hold Switch to ªClosedº and Vent Switch to ªClosedº)
C. With system pressurized at EVAP Service Port, check shaded areas for leaks (soapy
water can be used for leak detection). Diagnostic
Tips for Late
Type EVAP
System
(Continued)

ENGINE CONTROL
2. CONTROL SYSTEM
*SFI system
The SFI system monitors the engine condition through the signals, which are input from each sensor to the engine
control module. The best fuel injection volume is decided based on this data and the program memorized by the engine
control module, and the control signal is output to TERMINALS #10+, #20+, #30+ and #40+ of the engine control
module to operate the injector. (Inject the fuel). The SFI system produces control of fuel injection operation by the engine
control module in response to the driving conditions.
*ESA system
The ESA system monitors the engine condition through the signals, which are input to the engine control module from
each sensor the best ignition timing is detected according to this data and the memorized data in the engine control
module, and the control signal is output to TERMINALS IGT1 and IGT2. This signal controls the igniter to provide the
best ignition timing for the driving conditions.
*IAC system
The IAC system (Step motor type) increases the RPM and provides idling stability for fast idle±up when the engine is
cold and when the idle speed has dropped due to electrical load, etc. The engine control module evaluates the signals
from each sensor, outputs current to TERMINAL RSD , and controls the idle air control valve.
*Fuel control system
The engine control module operation outputs to TERMINAL FC and controls the CIR OPN relay. Thus controls the fuel
shutoff valve open and close.
*EGR control system
The EGR control system controls the VSV (EGR) by evaluating the signals from each sensor which are input to the
engine control module and by sending output to TERMINAL EGR of the engine control module.
*A/C conditioning operation system
In addition to the conventional A/C cut control, the engine control module performs the air conditioning operation as well
since the A/C amplifier function is built in it.
3. DIAGNOSIS SYSTEM
With the diagnosis system, when there is a malfunctioning in the engine control module signal system, the malfunction
system is recorded in the memory. The malfunctioning system can then be found by reading the display (Code) of the
malfunction indicator lamp.
4. FAIL±SAFE SYSTEM
When a malfunction occurs in any system, if there is a possibility of engine trouble being caused by continued control based
on the signals from that system, the fail±safe system either controls the system by using data (Standard values) recorded in
the engine control module memory or else stops the engine.
E4 (A), E5 (B), E6 (C), E7 (D) ENGINE CONTROL MODULE
BATT±E1 : Always 9.0±14.0 volts
+B±E1 :9.0±14.0 volts with the ignition SW at ON or ST position
VC±E2 :4.5± 5.5 volts with the ignition SW on
VTA±E2 :0.3± 0.8 volts with the ignition SW on and throttle valve fully closed
3.2±4.9 volts with the ignition SW on and throttle valve open
PIM±E2 :3.3± 3.9 volts with the ignition SW on
THA±E2 :0.5±3.4 volts with the ignition SW on and intake air temp. 20°C (68°F)
THW±E2 :0.2± 1.0 volts with the ignition SW on and coolant temp. 80°C (176°F)
STA±E1 :6.0±14.0 volts with the engine cranking
W±E1 :9.0±14.0 volts with the no trouble and engine running
TE1±E1 :9.0±14.0 volts with the ignition SW on
NSW±E1 :0± 3.0 volts with the ignition SW on and Park/Neutral position SW position P or N position
9.0±14.0 volts with the ignition SW on and except Park/Neutral position SW position P or N position
IGT1, IGT2±E1 : Pulse generation with the engine cranking or idling
#10+, #20+, #30+, #40+±E01, E02 :9.0±14.0 volts with the ignition SW on
SERVICE HINTS