Intake air control valve HONDA CR-V 1997 RD1-RD3 / 1.G User Guide

ldle Control System
ldle Control System
I P0505 | The scan tool indicates Diagnostic T.ouble Code (DTCI PO5O5: ldlecontrol svstem mattunction.
NOTE: lf DTC P1508 is stored at the same time as DTC P0505, troubleshoot DTC P1508 first. then troubleshoot DTC p0505.
Possibls Cause
. IAC valve mechanical malfunction. Throttle body clogged port, improper adlustment. Intake manifold gasket leakaging. Intake air hose loose leakaging. Vacuum hose leakaging
a ECT sensor incorrect output. Throttle Position sensor incorrect output
Troubleshooting Flowchart
The MIL has been reDorted on.DTC P0505 is sto.ed.
Problem verificationi1. Start the engine. Hold theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator Ian comes on, thenlet it idle.2. With the scan tool, check thelollowing items.- Throttle position should beapprox. 10% with the throt-tle {ully closed.- Engine coolant temperature shorJld be 194 - 205'F(90 - 96"C).lf they are not within thespec., repair the faulty sen-sor circuit.3 Check the engine speed atidle with no-load conditions:headlights, blower fan. reardefogger, radiator lan, and airconditioner are not operaling,
Inte.mittent failure. syltem is OKat this time.ls it 750 {730)* i 50 rpm?
ls il 700 (680)' rpm or less?
{To page 11-151)(To page 1'l-151)
l:'99 - 00 models
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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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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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Transmission
Removal
@
2.
'1.
Make sure lifts. iacks, and safety stands aro placed
properly, and hoist brackets are attached to the col-
rest position on the engine lsee section 11.
Apply th€ parking brake and block the r€ar wheels,
so vehicls will noi roll off the stands and fall on you
while working under it.
NOTE: Use fender covers to avoid damaging painted
surfaces.
Disconnect the negative terminal, then disconnect
the positive terminal from the battery.
Remove the intake air duct and the air cleaner hous-
ing assembly,
Remove the starter cables. Remove the harness
clamp from the clamp bracket.
5.
STARTERCABLES
Remove the transmission ground cable terminal
and the radiator hose clamp lrom the transmission
hanger.
Disconnect the lock-up control solenoid valve con-
nector, then remove the harness clamp from the
clamp bracket.HARNESS CLAMP
RADIATOR HOSECLAMP
CONTROLSOLENOID VALVECONNECTOR
CLAMP
6. Disconnect the vehicle speed sensor (VSS), the coun-
tershaft speed sensor, and the A/T gear position
switch connectors.
A/T GEAR POSITIONSWITCH CONNECTOR
VEHICLE SPEEDSENSOR |VSS'
CONNECTORBfiACKET
SPEED SENSORCONNECTOR
7. Remove the transmission housing mounting bolts.
MOUNTING BOLTS
(cont'd)
14-169
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26. Connect the vehicle speed sensor (VSS). the coun-
tershaft speed sensor. and the A,/T gear position
switch connectors,
VEHICLE SPEEO
SPEED SENSOACO'{NECTOR
Connect the lock-up control solenoid valve connec-
tor, then install the harness clamp on the clamp
bracket.
HARNESS CI-AMP
27.
RADIATOR HOSECLAMP
TRANSMISSIONGROUND CAB1ITERMINAL
LOCK-UP OONTROLSOLENOID VALVECONNECTOR
6x1.0mm12 N'm (1.2 kgi.m,8.? tbtftl
28.
29.
Instail the transmission ground cable terminal on
the transmission hanger, and install the radiator
hose clamp on the transmission hanger,
Connect the starter cables to the starter, and install
the harness clamD on the clamD bracket. Make sure
the crimped side of the starter cable ring terminal is
facing out.
STARTEBCABLE
STARTER CAAtf,
Install the air cleaner housing assembly and the
intake air duct.
Refill the transmission with ATF (see page 14-161).
Connect the battery positive terminal and negative
terminal.
Set the parking brake, Start the engine, and shift the
transmission through all gears three times.
Check the shift cable adjustment (see page 14-271]-.
Check the tront wheel alignment and adjust it if
needed (see section 18).
Let the engine reach normal operating temperature
(the radiator fan comes on) with the transmission in
E or N position, then turn it off and check the ATF
level {see page 14-160).
Perform a road test (see page 14-157 and 14-158).
30.
31.
34.
CLAMP BRACKET
37.
14-263
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