Page 2217 of 4592
DI±66
± DIAGNOSTICSENGINE
NG Replace VSV for EGR.
OK
Check for open and short in harness and con-
nector between engine room J/B No.2 and
ECM (See page IN±29).
4 Check EGR system (See Pub. No. RM654U, page EC±12).
NG Repair or replace.
OK
5 Check EGR vacuum modulator (See Pub. No. RM654U, page EC±12).
NG Repair or replace.
OK
6 Check EGR valve (See Pub. No. RM654U, page EC±12).
NG Repair or replace.
OK
7 Check manifold absolute pressure sensor (See Pub. No. RM654U, page SF±53).
NG Repair or replace.
OK
Page 2218 of 4592
A09281
A09423
ON
E6 Connector
EGR
OFF
Air
FilterON
Air
E
G E
VSV is ON
VSV is OFF Air
G
± DIAGNOSTICSENGINE
DI±67
Check and replace ECM (See page IN±29).
OBD II scan tool (excluding TOYOTA hand±held tester):
1 Check connection of vacuum hose and EGR hose (See Pub. No. RM654U, page
EC±12).
NG Repair or replace.
OK
2 Check VSV for EGR.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Disconnect the E6 connector from the ECM.
(c) Turn the ignition switch ON.
CHECK:
Check the VSV function.
(1) Connect between terminal EGR of the ECM con-
nector and body ground (ON).
(2) Disconnect between terminal EGR of the ECM con-
nector and body ground (ON).
OK:
(1) VSV is ON:
Air from port E is flowing out through the air filter.
(2) VSV is OFF:
Air from port E is flowing out port G.
OK Go to step 4.
NG
3 Check operation of VSV for EGR (See Pub. No. RM654U, page SF±43).
NG Replace VSV for EGR.
OK
Page 2219 of 4592
DI±68
± DIAGNOSTICSENGINE
Check for open and short in harness and con-
nector between engine room J/B No.2 and
ECM (See page IN±29).
4 Check EGR system (See Pub. No. RM654U, page EC±12).
NG Repair or replace.
OK
5 Check EGR vacuum modulator (See Pub. No. RM654U, page EC±12).
NG Repair or replace.
OK
6 Check EGR valve (See Pub. No. RM654U, page EC±12).
NG Repair or replace.
OK
7 Check manifold absolute pressure sensor (See Pub. No. RM654U, page SF±53).
NG Repair and replace.
OK
Check and replace ECM (See page IN±29).
Page 2220 of 4592
A00414
Vehicle
Speed Sensor4±Pulse 4±Pulse
Combination Meter
ECM
Transaxle
Vehicle Speed Sensor
A09398
Combination Meter
14
V±WV±W
B J15
J/C
IF1
BV±W9
SPD5 V ECM
3
C11E4
± DIAGNOSTICSENGINE
DI±69
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
The No.1 vehicle speed sensor outputs a 4±pulse signal for every revolution of the rotor shaft, which is ro-
tated by the transmission output shaft via the driven gear. After this signal is converted into a more precise
rectangular 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
P0500During vehicle is being driven, no vehicle speed sensor signal
to ECM (2 trip detection logic)
Combination meter
Open or short in vehicle speed sensor circuit
Vehicle speed sensor
ECM
WIRING DIAGRAM
DI01B±12
Page 2221 of 4592

A09289BE6653A09267
SPD
ON
(+) (±)
AT7809
4.5 ± 5.5 V
0
Turn the wheel
DI±70
± DIAGNOSTICSENGINE
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 was warmed up or not, the air±fuel ratio was 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 speedmeter in the combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer circuit. See combination
meter troubleshooting (See Pub. No. RM654U,
page BE±2).
OK
2 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Shift the shift lever to neutral.
(c) Jack up one of the front wheels.
(d) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal SPD of the ECM con-
nector and body ground when the wheel is turned slowly.
OK:
Voltage is generated intermittently.
NG Check and repair harness and connector be-
tween combination meter and ECM.
Page 2222 of 4592
± DIAGNOSTICSENGINE
DI±71
OK
Check and replace ECM (See page IN±29).
Page 2223 of 4592

A01758
Throttle Valve
To Cylinder ECM SignalFrom
Air
Cleaner
Valve
IAC Valve
Intake Air
Chamber
A09420
Driver Side J/BEFI Relay
Engine Room R/B No.2 From
IG SwitchFrom
BatteryECM
E6 10
w
1
3 2 IAC Valve
B±Y
IG39
EB
B±Y
W±B 4
12 3 5 21EFI
B
37
1W 1KIGN
B±R
W±B
EC
RSD
7 12
2A
2J
2K
2FJ18
J/C
B B
DI±72
± DIAGNOSTICSENGINE
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located on the throttle
body 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
Open or short in IAC valve circuitOpen or short in IAC valve circuit
IAC valve is stuck or closed
P0505Idle speed continues to vary greatly from the target speed
(2 trip detection logic)
IAC valve is stuck or closed
Open or short in A/C switch circuit
Air induction system
ECM
WIRING DIAGRAM
DI3A3±03
Page 2224 of 4592

± DIAGNOSTICSENGINE
DI±73
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 was warmed up or not, the air±fuel ratio was lean
or rich, etc. at the time of the malfunction.
TOYOTA hand±held tester:
1 Check idle speed.
PREPARATION:
(a) Warm up the engine to normal operating temperature.
(b) Switch off all the accessories.
(c) Switch off the A/C.
(d) Shift the transmission into the N or neutral position.
(e) Remove the fuse cover on the instrument panel.
(f) Connect the TOYOTA hand±held tester to the DLC3 on the vehicle and select the ACTIVE TEST
mode.
CHECK:
Check the difference of engine speed between the ones, less than 5 sec. and more than 5 sec. after switch-
ing the TE1 from OFF to ON by the TOYOTA hand±held tester.
OK:
Difference of engine speed: More than 100 rpm
OK Go to step 8.
NG
2 Check for IAC duty signal.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the TOYOTA hand±held tester to the DLC3 on the vehicle.
(c) Turn the ignition switch ON and push the TOYOTA hand±held tester main switch ON.
CHECK:
Read the IAC duty ratio on the TOYOTA hand±held tester.
OK:
IAC duty ratio: 27 ± 47 %
OK Go to step 3.
NG
Check and replace ECM (See page IN±29).