TOYOTA CAMRY 1999 Service Repair Manual

A07149
ON
TPC
OFFON
VSV is ON
VSV is OFF
Air
E
FG Air
G E
F
± DIAGNOSTICSENGINE (1MZ±FE)
DI±329
564 Author: Date:
8 Check for open and short in harness and connector between EFI main relay
(Marking: EFI) and VSV for EVAP and ECM (See page IN±31).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±31).
9 Check VSV for vapor pressure sensor.
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Turn the ignition switch ON.
CHECK:
Check VSV function.
(1) Connect between terminal TPC of the ECM connec-
tor and body ground (ON).
(2) Disconnect between terminal TPC of the ECM
connector and body ground (OFF).
OK:
(1) VSV is ON:
Air from pipe E is flowing out through pipe F.
(2) VSV is OFF:
Air from pipe E flows out through pipe G.
OK Check and replace charcoal canister
(See page EC±6).
NG

DI±330
± DIAGNOSTICSENGINE (1MZ±FE)
565 Author: Date:
10 Check operation of VSV for vapor pressure sensor (See page SF±62).
OK Go to step 11.
NG
Replace VSV and clean the 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 the 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).

A01655
Charcoal CanisterVapor Pressure
Sensor
VSV for Vapor
Pressure Sensor
Fuel Tank VSV
for EVAPECM
Fuel Tank Over
Fill Check Valve
± DIAGNOSTICSENGINE (1MZ±FE)
DI±331
566 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 or p0451 is recorded by the ECM when the vapor pressure sensor malfunction.
DTC No.DTC Detecting ConditionTrouble Area
P0450
10 seconds or more after engine starting condition (a) or (b)
continues for 7 seconds or more:
(2 trip detection logic)
(a) Vapor Pressure Sensor Value
< ±3.5 kPa (±26 mmHg,
±1.0 in.Hg)
(b) Vapor Pressure Sensor Value
1.5 kPa (15 mmHg,
0.4 in.Hg)

Open or short in vapor pressure sensor circuit
V
P451
Vapor pressure sensor output extremely changes under
conditions 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.
Vapor pressure sensor

ECM
DI1K5±03

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.

A00223
Vehicle Speed
Sensor
Combination
Meter
ECM
Transaxle4±Pulse 4±Pulse
Vehicle Speed Sensor
Q00515 Q00514
A03316
Combination
MeterJ15
Junction
Connector
14
C93
V±W V±W V±WECM
SPD5V
BBE8 22
IG3
± DIAGNOSTICSENGINE (1MZ±FE)
DI±333
568 Author: Date:
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
The vehicle speed sensor outputs a 4±pulse signal for every revolution of the rotor shaft, which is rotated
by the transmission output shaft via the driven gear. After this signal is converted into a more precise rectan-
gular waveform by the waveform shaping circuit inside the combination meter, it is then transmitted to the
ECM. The ECM determines the vehicle speed based on the frequency of these pulse signals.


DTC No.DTC Detecting ConditionTrouble Area
P0500
No vehicle speed sensor signal to ECM under conditions (a)
and (b):
(2 trip detection logic)
(a) Park/neutral position switch is OFF
(b) Vehicle is being driven
Open or short in vehicle speed sensor circuit

Vehicle speed sensor

Combination meter

ECM
WIRING DIAGRAM
DI082±06

A02030
SPD
E8
DI±334
± DIAGNOSTICSENGINE (1MZ±FE)
569 Author: Date:
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.
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedmeter display is normal.
NG Check speedmeter circuit.
OK
2 Check for short in harness and connector between terminal SPD of ECM and
body ground (See page IN±31).
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Disconnect the E8 connector of ECM.
CHECK:
Check continuity between terminal SPD of ECM and body
ground.
OK:
No continuity (1 MW or higher)
NG Repair or replace harness or connector.
OK

A02029
ON
SPD (+)
E8
± DIAGNOSTICSENGINE (1MZ±FE)
DI±335
570 Author: Date:
3 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Turn the ignition switch ON.
(b) Disconnect the E8 connector of ECM.
CHECK:
Measure voltage between terminal SPD of the ECM connector
and body ground.
OK:
Voltage: 9 ~ 14 V
NG Check for open in harness and connector
between junction connector (J15) and ECM
(See page IN±31).
OK
4 Check for open in harness and connector between junction connector (J14) and
combination meter (See page IN±31).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±31).

P01559
Throttle Valve
From
Air
Cleaner
Signal
ECM
ValveIAC Valve
To Cylinders Intake Air Chamber
A07448
From
BatteryFL
MAIN
EC
F4 F611Fusible
Link
Block
B1
7 2
5EFI Engine Room J/B
EFI Relay1
23
5 2A
2K 2J
2C W±BIAC Valve
J27J28
B±Y
9II3
21
3E1116
15ECM
RSO
E01
RSC
E01 AA
B±W
MREL
B+ E11
E78
B±G
BB±YB±Y
J36
J35 AC J16
Junction
Connector
B±YR±W
Y±B
B±W
Junction
ConnectorB
Junction
Connector B DI±336
± DIAGNOSTICSENGINE (1MZ±FE)
571 Author: Date:
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located in front of the in-
take air chamber and intake air bypassing the throttle valve is
directed to the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle±up and
provide feedback for the target idling speed.
DTC No.DTC Detecting ConditionTrouble Area
P0505Idle speed continues to vary greatly from target speed
(2 trip detection logic)

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)

ECM
WIRING DIAGRAM
DI083±06

± DIAGNOSTICSENGINE (1MZ±FE)
DI±337
572 Author: Date:
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.
1 Check engine idle speed.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off air conditioning.
(d) Shift transmission into ºNº or neutral position.
(e) Connect the OBD II scan tool or TOYOTA hand±held tester to DLC3 on the vehicle.
(f) Using SST, connect terminals TE1 and E1 of the DLC3.
CHECK:
Check the difference of engine speed between the ones less than 5 sec. and more than 5 sec. after connect-
ing terminals TE1 and E1 of the DLC1.
OK:
Difference of engine speed: More than 100 rpm
OK Go to step 6.
NG

A02031
ON
RSO (+)E11
RSC (+)
DI±338
± DIAGNOSTICSENGINE (1MZ±FE)
573 Author: Date:
2 Check voltage between terminals RSO, RSC of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Disconnect the E11 connector of ECM.
(c) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals RSO, RSC of the ECM
connector and body ground.
OK:
Voltage: 9 ~ 14 V
OK Go to step 4.
NG
3 Check IAC valve (See page SF±46).
NG Replace IAC valve.
OK
Check for open and short in harness and connector between engine room J/B and IAC valve, IAC
valve and ECM (See page IN±31).
4 Check operation of IAC valve (See page SF±42).
NG Repair or replace IAC valve.
OK