2000 HONDA CR-V Air Intake

ldle Control System
ldle Air Control llAC) Valve
The scan tool indicates Diagnostic Trouble Code (DTC) Pl508: A probtem in the ldle Air Controt flAC) varvecircuit.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the ECM/PCM inorder to maintain the proper idle speed.
37 model;
IAC VALVE 2P CONNECTOR {C132}
,f rcp'# IYEL/BI.(II2f-1-d)
Y
Wir€ side of female terminals
PCM CONNECTOR A I32PI
tacvIBLK/BLU)
From AIR To INTAKECLEANER MANIFOLD
Wire side of female terminals
The MIL has beon .eport€d on.OIC Pl508 is sto.ed.
Problem veiification:1. Do the PCM Reset Procedure.2. Start the engine, and warm itup to normal operating tem-perature.
Inte.mittent failure, systcm b OKat thi3 time. Check tor poo. con-nections or loose wircs at C132(lAC v.lvel and at the PCM.
ls DTC Pl508 indicated?
Check lor an open in the wir6{lGPl lins}:1. Turn the ignition switch OFF.2. Disconnect the IAC valve 2Pconnector.3. Turn the ignition switch ON {ll).4. Measure voltage between bodyground and the IAC valve 2Pconnector term inal No.2.
Repair open in the wire trctwoontha IAC v!lv6 and the PGM-Flmain relly.
Chock for an opan o. short in thowi.e (lACv linel:1. Turn the ignition switch OFFand reconnect the IAC valve2P connector.2. Disconnect the PCM conneclorA (32P).
3. Turn the ignition switch ON {ll).4, Measure voltage betweenbody ground and PCM con-nector terminal A12.
{To page 1l-153)
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ldle Control System
Fast ldle Thermo Valve lA/T)
Description
To prevent erratic running when the engine is warming
up, it is necessary to raise the idle speed. The fast idle
thermo valve is controlled by a thermowax plunger.
When the engine is cold, the engine coolant surround-
ing the thermowax contracts the plunger, allowing addi-
tional air to be bvDassed into the intake manifold so that
the engine idles faster. When the engine reaches operat-
ing temperature. the valve closes, reducing the amount
of air bypassing into the intake manifold.
IDLEADJUSTING
IDLETHERMOVALVE
AIR BYPASS VALVE
11-168
Inspgction
NOTE: The fast idle thermo valve is factory adjusted; it
should not be disassembled.
1. Remove the intake air duct from the throttle body.
2. Start the engine,
3. Put your finger over the lower port in throttle body,
and make sure that there is air flow with the engine
cold (engine coolant temperature below 86"F, 30'C).
lf there is no air flow, replace the fast idle thermo
valve and retest,
O-RINGSReplace.
11.0 kgfl.m, 7.2 lbl.ftl
Start the engine. Hold the engine at 3,000 rpm with no
load (in Park or neutral) until the radiator fan comes
on, then let it idle.
Check that the valve is completely closed. lf the valve
is leaking, the idle speed will drop when you cover the
lower pon. Check the engine coolant level and for air
in the engine cooling system {see section 10). lf the
cooling system is OK, replace the fast idle thermo
valve and recheck.
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Intake Air System
System Description
The system supplies air for all engine needs. lt consists of the intake air pipe, Air Cleaner, intake air duct, Throttle Body
(TB), ldle Air Control (lAC) Valve, fast idle thermo valve, and intake manifold. A resonator in the intake air pipe provides
additional silencing as air is drawn into the system.
INTAKE MANIFOLD
YEL| - - Fiom PGM'FI
BLK T MAIN RELAY
IDLETHERMO
lJ- _iuo'u'j"'
INTAKEAIR DUCT
vaRtousSENSORS
FESONATON
THROTTLEBODY (TB)
1 1-193
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Intake Air System
Air Cleaner
Air Cleaner Eloment Rsplacomsnt
NOTE: Do not clean the air cleaner element by blowingit off with compressed air,
AIR CLEANER ELEMENTNo.mal conditions:Replace air cleaner element every30,000 miles {48,000 km) or 24months whichever comes first.Severe condition3:Replace air cleaner element every15,000 miles 124,000 km) or 12months whichever comes tirst.
m
11-194
Throttle Cable
Inrpection/Adiustmcnt
1. Stan the engine. Hold the engine at 3,000 rpm with noload (in Park or neutral) until the radiator fan comeson, then let it idle.
2. Check that the throttle cable operates smoothly withno binding or sticking. Repair as necessary,
3. Check cable free play at the throttle linkage. Cabtedeflection should be 10- 12 mm (3/8 - 1l2in.l.
'97 - 98 modols:
CABLEBRACKET
LOCKNUT
DEFLECTION10-12mmBIA- 112 i^l
'99 - 0O modsls:
lf deflection is not within specs, loosen the locknut,turn the adjusting nut untilthe deflection is as speci-fied, then retighten the locknut.
With the cable properly adjusted. check the throttlevalve to be sure it opens fully when you push theaccelerator pedal to the floor. Also check the throt-tle valve to be sure it returns to the idle position
whenever you release the accelerator pedal.
DEFLECTIONl0-12mft
Bla - 112 inl
NUT
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Intake Air System
Throttle Body
Doscription
The throttle body is a single-barrel side-draft type. The
lower portion of the throttle valve is heated by engine
coolant from the cylinder head. The idle adjusting screw
which regulates the bypass air is located on the top of
the throttle bodv.
The illustration shows'97 - 98 models,'99 - 00 rnodelsare similar.
1 1-196
lnspection
Check that the throttle cable operates smoothly without
binding or sticking.
lf there are any abnormalities, check for:. Excessive wear or play in the throftle valve shaft.. Sticky or binding throttle lever at the fully closed posi-
tton.
. Clearance between throttle stop screw and throttle
lever at the fully closed position.
97 - 98 models:
THROTTLE LINKAGE
Replace the throttle body if there is excessive play in the
throttle valve shaft or if the shaft is binding or sticking.
THROTTLE LINKAGE
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Intake Air System
Throttle Body (cont'd)
Disassembly
O-RING {A/l only)Replace.
IDLE THERMOVALVE (A/T only)
ADJUSTINGSCREW
9.8 N.m(1.0 kgl.m,7.2 lbf.ftl
The illustration shows'97 - 98models,'99 00 models are similar.
1 1-198
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Positive Grankcase Ventilation (PGVI System
Description
The Positive Crankcase Ventilation (PCV) svstem is
designed to prevent blow-by gas from escaping to the
atmosphere. The PCV valve contains a spring-loaded
plunger, When the engine starts, the plunger in the PCV
valve is lifted in proportion to intake manitold vacuum and
the blow-by gas is drawn directly into the intake manifold.
-: BLOW.BY VAPOR-: FRESH AIR
i/lAlrllFOLD
Inspoction
1. Check the PCV hoses and connections for leaks and
clogging.
'97 - 98 models:
'99 - (X) models:
BREATHERHOSE
(cont'd)
11-201
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EVAP PURGE CONTROL SOLENOID VALVE DUTY CONTROLLED AFTER
STARTING ENGINE
ENGINE COOLANT TEMPERATURE ABOVE 154"F (68'C)
Evaporative Emission (EVAP) Controls
Description:
The evaporative emission controls are designed to minimize the amount of fuel vapor escaping to the atmosphere. The
system consists of the following components:
A. Evaporative Emission (EVAPI Control Canister
An EVAP control canister is used for the temporary storage of fuel vapor until the luel vapor can be purged from the
EVAP control canister into the enqine and burned.
B. Vapor Purge ConirolSystem
EVAP control canister purging is accomplished by drawing fresh air through the EVAP control canister and into a pon
on the intake manifold. The purging vacuum is controlled by the EVAP purge control solenoid valve.
C. Fuel Tank Vapor Control System
When fuel vapor pressure in the fuel tank is higher than the set value of the EVAP two way valve, the valve opens and
regulates the flow ot fuel vapor to the EVAP control canister.
'97 model:
EVAPPURGECONTROL
VALVEFromNo. 15BLK/ /ALTERNATORYEL I sP SENSOR r7.s At(in the under-dashfuse/relay box)
VARIOUSSENSORFEESH AIF
BLK
I
FUEI- TANK
(cont'd)
11-203
INTAKE MANIFOLD
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