Page 1065 of 2267
Wiring DiagramNCEC0284
YEC845
: Detectable line for DTC
: Non-detectable line for DTC
ECM ECM
RELAYRefer to EL-POWER. BATTERY
IACV-AAC
VA LV E
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Wiring Diagram
EC-265
Page 1066 of 2267

Diagnostic ProcedureNCEC0285
1 CHECK POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect IACV-AAC valve harness connector.
SEF221X3. Turn ignition switch ªONº.
4. Check voltage between terminal 2, 5 and ground with CONSULT-II or tester.
SEF352QAVoltage: Battery voltage
OK or NG
OK©GO TO 3.
NG©GO TO 2.
2 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors F73, E90
IHarness for open or short between IACV-AAC and ECM relay
I10A fuse
©Repair harness or connectors.
3 CHECK OUTPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between
ECM terminal 6 and terminal 1,
ECM terminal 7 and terminal 4,
ECM terminal 15 and terminal 3,
ECM terminal 16 and terminal 6.
Refer to wiring diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 4.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
IACV-AAC valve
harness connector
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Diagnostic Procedure
EC-266
Page 1067 of 2267
4 CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-I
1. Reconnect the ECM harness connector and IACV-AAC valve harness connector.
2. Disconnect vacuum hose connected to air control valve (Power steering) at intake air duct.
3. Start and let it idle.
4. Check vacuum hose for vacuum existence.
SEF969X
Vacuum slightly exists or does not exist.
OK or NG
OK©GO TO 5.
NG©Replace air control valve (Power steering).
5 CHECK AIR CONTROL VALVE (POWER STEERING) OPERATION-II
Check the vacuum hose for vacuum existence when steering wheel is turned.
SEF969X
Vacuum should exist.
OK or NG
OK©GO TO 8.
NG©GO TO 6.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Diagnostic Procedure (Cont'd)
EC-267
Page 1068 of 2267
6 CHECK VACUUM PORT
1. Stop engine.
2. Disconnect vacuum hose connected to air control valve (Power steering) at the vacuum port.
3. Blow air into vacuum port.
4. Check that air flows freely.
SEF970X
OK or NG
OK©GO TO 7.
NG©Repair or clean vacuum port.
7 CHECK VACUUM HOSES AND TUBES
1. Disconnect vacuum hoses between air control valve (Power steering) and vacuum port, air control valve (Power steer-
ing) and intake air duct.
2. Check hoses and tubes for cracks, clogging, improper connection or disconnection.
SEF109L
OK or NG
OK©GO TO 8.
NG©Repair hoses or tubes.
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Diagnostic Procedure (Cont'd)
EC-268
Page 1069 of 2267

8 CHECK IACV-AAC VALVE
Refer to ªComponent Inspectionº, EC-SR-270.
OK or NG
OK©GO TO 9.
NG©Replace IACV-AAC valve.
9 REPLACE IACV-AAC VALVE
1. Replace IACV-AAC valve assembly.
2. Perform ªIdle Air Volume Learningº, EC-46.
Is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©INSPECTION END
INCMP©Follow the construction of ªIdle Air Volume Learningº.
10 CHECK TARGET IDLE SPEED
1. Turn ignition switch ªOFFº.
2. Reconnect all harness connectors and vacuum hoses.
3. Start engine and warm it up to normal operating temperature.
4. Also warm up transmission to normal operating temperature
IFor CVT models with CONSULT-II, drive vehicle until ªFLUID TEMP SEº in ªDATA MONITORº mode of ªCVTº system
indicates less than 0.9V.
IFor CVT models without CONSULT-II and M/T models, drive vehicle for 10 minutes.
5. Stop vehicle with engine running.
6. Check target idle speed.
M/T: 750 50 rpm
A/T: 750 50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 11.
NG©Perform ªIdle Air Volume Learningº, EC-45.
11 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-SR-114.
©INSPECTION END
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Diagnostic Procedure (Cont'd)
EC-269
Page 1070 of 2267
Component InspectionNCEC0286IACV-AAC VALVENCEC0286S011) Disconnect IACV-AAC valve harness connector.
2) Check IACV-AAC valve resistance.
Condition Resistance
Terminal 2 and terminals 1, 3
20-24W[at 20ÉC (68ÉF)]
Terminal 5 and terminals 4, 6
3) Reconnect IACV-AAC valve harness connector.
4) Remove idle air adjusting unit assembly (IACV-AAC valve is
built-in) from engine.
(The IACV-AAC valve harness connector should remain con-
nected.)
5) Turn ignition switch ªONº and ªOFFº, and ensure the IACV-
AAC valve shaft smoothly moves forward and backward,
according to the ignition switch position.
If NG, replace the IACV-AAC valve.
SEF353QA
SEF089X
DTC P0505 IDLE AIR CONTROL VALVE (IACV) Ð
AUXILIARY AIR CONTROL (AAC) VALVESR20DE
Component Inspection
EC-270
Page 1071 of 2267

Component DescriptionNCEC0287A closed throttle position switch and wide open throttle position
switch are built into the throttle position sensor unit. The wide open
throttle position switch is used only for CVT control.
When the throttle valve is in the closed position, the closed throttle
position switch sends a voltage signal to the ECM. The ECM only
uses this signal to open or close the EVAP canister purge control
valve when the throttle position sensor is malfunctioning.
CONSULT-II Reference Value in Data Monitor
Mode
NFEC0257Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
CLSD THL/P SEIEngine: IdleThrottle valve: Idle position ON
Throttle valve: Slightly open OFF
ECM Terminals and Reference ValueNCEC0288Specification data are reference values and are measured between each terminal and 48 (ECM ground).
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
40 YThrottle position switch
(Closed position)[Engine is running]
IAccelerator pedal releasedBATTERY VOLTAGE
(11 - 14V)
[Ignition switch ªONº]
IAccelerator pedal depressedApproximately 0V
On Board Diagnosis LogicNCEC0289
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0510
0510IBattery voltage from the closed throttle position switch is
sent to ECM with the throttle valve opened.IHarness or connectors
(The closed throttle position switch circuit is
shorted.)
IClosed throttle position switch
IThrottle position sensor
SEF505V
Throttle position switch
built into throttle
position sensor
Throttle position
switch connector
Throttle position
sensor connector
DTC P0510 CLOSED THROTTLE POSITION SWITCH
(IF SO EQUIPPED)SR20DE
Component Description
EC-271
Page 1072 of 2267

DTC Confirmation ProcedureNCEC0290CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch ªOFFº and wait at least 9 seconds
before conducting the next test.
With CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Check ignition switch ªOFFº, wait at least 9 seconds and then
start engine.
3) Select ªCLSD THL/P SWº in ªDATA MONITORº mode.
If ªCLSD THL/P SWº is not available, go to step 5.
4) Check the signal under the following conditions.
Condition Signal indication
Throttle valve: Idle position ON
Throttle valve: Slightly open OFF
If the result is NG, go to ªDiagnostic Procedureº, EC-SR-274.
If OK, go to following step.
5) Select ªDATA MONITORº mode with CONSULT-II.
6) Drive the vehicle for at least 5 consecutive seconds under the
following condition.
THRTL POS SEN More than 2.3V
VHCL SPEED SE More than 4 km/h (2 MPH)
Selector lever Suitable position
Driving pattern Driving vehicle uphill (Increased engine load)
will help maintain the driving conditions
required for this test.
7) If 1st trip DTC is detected, go to ªDiagnostic Procedureº, EC-
SR-274.
Overall Function CheckNCEC0291Use this procedure to check the overall function of the closed
throttle position switch circuit. During this check, a 1st trip DTC
might not be confirmed.
Without CONSULT-II
1) Start engine and warm it up to normal operating temperature.
2) Check the voltage between ECM terminal 40 (Closed throttle
position switch signal) and ground under the following condi-
tions.
Condition Voltage
At idle Battery voltage
At 2,000 rpm Approximately 0V
3) If NG, go to ªDiagnostic Procedureº, EC-SR-274.
SEF092X
PEF329U
SEF090X
CONNECT
DTC P0510 CLOSED THROTTLE POSITION SWITCH
(IF SO EQUIPPED)SR20DE
DTC Confirmation Procedure
EC-272