Page 2753 of 4770

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 drivenOpen or short in vehicle speed sensor circuit
Vehicle speed sensor
Combination meter
ECM
WIRING DIAGRAM
DI082±06
Page 2754 of 4770

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
Page 2755 of 4770
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).
Page 2756 of 4770

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
Page 2757 of 4770

± 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
Page 2758 of 4770
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
Page 2759 of 4770
± DIAGNOSTICSENGINE (1MZ±FE)
DI±339
574 Author: Date:
5 Check the blockage of IAC valve and the passage to bypass the throttle valve.
NG Repair or replace IAC valve.
OK
Check and replace ECM (See page IN±31).
6 Check for A/C signal circuit (See page AC±88).
NG Repair or replace.
OK
Check air induction system
(See page SF±1).
Page 2760 of 4770

DI±340
± DIAGNOSTICSENGINE (1MZ±FE)
575 Author: Date:
DTC P1130 A/F Sensor Circuit Range/Performance Mal-
function (Only for California Spec.)
DTC P1150 A/F Sensor Circuit Range/Performance Mal-
function (Only for California Spec.)
CIRCUIT DESCRIPTION
Refer to DTC P0125 (Insufficient Temp. for Closed Loop Fuel Control (Only for California Spec.)) on Page
DI±249.
DTC No.DTC Detecting ConditionTrouble Area
Voltage output* of A/F sensor remains at 3.8 V or more, or
2.8 V or less, during engine running after engine is warmed
up (2 trip detection logic)
*: Output value changes at inside of ECM only.
P1130
P1150Voltage output* of A/F sensor does not change from 3.30 V,
during engine running after engine is warmed up
(2 trip detection logic)
*: Output value changes at inside of ECM only.Open or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
ECM
Open or short in A/F sensor circuit
(2 trip detection logic)
HINT:
After confirming DTC P1130 or P01150, use the OBD II scan tool or TOYOTA hand±held tester to con-
firm voltage output of A/F sensor (AFS B1 S1/O2S B1 S1) from ºCURRENT DATAº.
The A/F sensor's output voltage and the short±term fuel value can be read using the OBD II scan tool
or TOYOTA hand±held tester.
The ECM controls the voltage of AFR/AFL and AFR/AFL terminals of ECM to the fixed voltage.
Therefore, it is impossible to confirm the A/F sensor output voltage without OBD II scan tool or TOYOTA
hand±held tester.
OBD II scan tool (excluding TOYOTA hand±held tester) displays the one fifth of the A/F sensor output
voltage which is displayed on the TOYOTA hand±held tester.
WIRING DIAGRAM
Refer to DTC P0125 (Insufficient Coolant Temp. for Closed Loop Fuel Control (Only for California Spec.))
on page DI±249.
DI1K6±03