1999 HONDA CIVIC Idle air control

Gomponent Locations
L
lndex
D16Y5 engine:
{IATISENSORTroubleshooting,
ELECTRICAL LOADDETECTOR IELD) (USA mod6l)Troubleshooting, page 11 179
THROTTLE POSITION ITP)SENSORTroubleshooting, page 1 1-132
MANIFOLD ABSOLUTEPRESSURE IMAPI SENSORTroubleshooting, page 1'l-115
EXHAUST GAS RECIRCULATION
IEGRI VALVE and EXHAUST GAS
RECIRCULATION IEGRI VALVE
LIFT SENSORTroubleshooting, page'l 1-254
INTAKE AIR TEMPERATUR€
IDLE AIR CONTROL (IAC) VALVE
{M/T)Troubleshooting, page 1 1-194
EXHAUST GAS RECIRCULATION{EGRI CONTROL SOLENOIDVALVE ICW)Troubleshooting. page 1 1-254
EVAPORATIVE EMISSIONIEVAPI PUNGE CONTROLSOLENOID VALVETroubf eshooting, Page 1 1'21 1, 243
CRANKSHAFTPOS|TTON/TOP DEAD CENTER/CYLINDERPOS|T|ON
POWER STEERING PRESSURE(PSP) SWITCH (USAI
Troubleshooting, Page 1 1-212
KNoCK SENSoR (Ks)
(cwl
Troubleshooting, Page 1 1'170ICKP/TDC/CYP} SENSOR(Built into the distributor)Troubleshooting, Page 1 1'172
VEHICLE SPEED SENSORTroubleshooting, Page 1 1-176
FLUCTUATION (CKF} SENSOR
Troubleshooting, Page 1 1 -183
ENGINE COOLANTTEMPERATUREIECT) SENSORTroubleshooting, Page 11 128
IDT.ECONTROL IIACI VALVE
{cw)Troubleshooting, Page 11 198
WAY CATALYTICCONVERTER ITWCITroubleshooting, Page 1 1-252PRIMARY TIEATEDSENSOR {PNIMARY HO2SI
tsENsoR 1t {M/TlTroubleshooting, Page'l 1-146
PRIMARY HEATED OXYGENSENSOR (PRIMARY HO2SI
tsENsoR 1l {cw}Troubleshooting, Page 1 1-139
SECONDARY HEATED OXYGENSENSOR {SECONDARY HO2S){SENSOR 2)Troubleshooting, page 11 153
(cont'd)
1 1-3

D16Y7 engine:
ELECTRICAL LOAO
DETECTOR (ELD) IUSA}Troubleshooting, Page 11'179
THROTTLE POSITION ITPISENSOR
MANIFOLD ABSOLUTEPRESSURE (MAPI SENSORTroubleshooting, Page 1 1-1 15r1-132
CRANKSHAFTPOSTTTON/TOP DEAD CENTER/
CYLINDERPOSITION
POWER STEERll\lG PRESSURE
{PSP' SWTTCH {USA)Troubleshooting, Page 11 212
IDLE AIR CONTROL (IAC) VALVE
Troubleshooting, page 1 1-198
Troubleshooting,
VEHICLE SPEED SENSOR (VSSI
Troubleshooting, Page 1 1-176
INTAKE AIR TEMPERATURE
IIATI SENSORTroubleshooting, page 11 124
l
/i
CRANKSHAFT SPEED
{CKP/TDC/CYPI SENSOR(Built into the distributorlTroubleshooting, Page 't 1-172
FLUCTUATION ICKFI SENSORTroubleshooting, Page 1 1-183
PRIMARY HEATED OXYGEN
SENSOR (PRIMARV HO2S)
{SENSOR 1lTroubleshooting, page 1 1'139
ENGINE COOLANTTEMPERATURE(ECTI SENSORTroubleshooting, page 11 128
EVAPOBATIVE EMISSION(EVAPI PURGE CONTROLSOLENOID VALVE
THNEE WAY CATALYTICCONVERTER ITWCITroubleshooting, page 1 1-252
Troubf eshooting, page 1 1 27 1, 283
SECONDARY HEATED OXYGENSENSOR (SECONDARY HO2S)(SENSOR 2lTroubleshooting, Page 1 1-1 53
(cont'd)
,l .ltr| | -r,

System Description
Vacuum Connections (cont'd)
D16Y5 engine ('98 modet):
-: Vacuum hose No,*: CW only
(9 POSITIVE CRANKCASE VENTILATION {PCV} VALVE?!J EXHAUST GAS BECIRCULATION (EGR}CONTROLSOLENOIO VALVE'1 ExHAUST GAs RECIRCULATIoN IEGRI VALVE22 EXHAUST GAS RECIRCULATION {EGR} VALVE LIFISENSOR€J EvApoRATtvE EMtsstoN {EvAp} puRGE coNTRoLSOLENOID VALVEq4 PURGE JOINT@ EVAPoRATIVE EMIssIoN {EVAP) coNTRoL CANISTER@ EVAPORATIVE EMISSION IEVAP} BYPASS SOLENOIDVALVE?? EVAPORATIVE EMISSION {EVAP) THREE WAY VALVEITII EVAPORATIVE EMISSION IEVAP} CONTROL CANISTERVENT SHUT VALVEO FUEL TANK PRESSURE sENsoRQlI EVAPORATIVE EMISSION {EVAP}TWO WAY VALVE8' THREE WAY CATALYTIC CONVERTER {TWCI
il) PRIMAFY HEATED OXYGEN SENSOR IPRIMARY HO2S.SENSOR 1)O SECoNDARY HEATEo oxYGEN sENsoR {sEcoNDARYHO2S. SENSOB 2)iq] MANIFOLD ABSOLUTE PRESSURE (MAPI SENSORO ENGINE COOLANT TEMPERATURE IECT) SENSOR5 INTAKE AIR TEMPERATURE {IATI SENSOR! KNOCK SENSOR tKSlO CRANKSHAFT SPEED FLUCTUATIoN {cKF) sENsoFO IDLE AIR coNTRoL {IAc) vALvE99 THROTTLE BODY ITBI@ FUEL INJECToRO FUEL PULSATION DAMPER@ FUEL F -TER@ FUEL PRESSURE REGULAToR[4 FUEL PUMP IFPI(9 FUEL TANK(D FUEL TANK EVAPoRATIVE EMIssIoN IEVAPI VALVEO' AIR CLEANER(D RESoNAToR
11-20

System Description
Vacuum Connections (cont'd)
D16Y8 engine ('96 sedan, '97 sedan: KA, KC modelsl:
PRIMARY HEATED OXYGEN SENSOR (PRIMARY HO2S.SENSOR SECONOARY HEATED OXYGEN SENSOR {SECONDARYHO2S, SENSOR 2lMANIFOLD ABSOLUTE PRESSUBE {MAPI SENSORENGINE COOLANT TEMPERATURE {ECTI SENSORINTAKE AIR TEMPERATUFE IIATI SENSORKNOCK SENSOR IKSICRANKSHAFT SPEED FLUCTUATION {CKFI SENSORIDLE AIR CONTROL IIACI VALVETHROTTLE EODY (T8)FUEL INJECTORFUEL FILTER
FUEL PRESSURE REGULATORFUEL PUMP {FPIFUEL TANKFUEL TANK EVAPORATIVE EMISSION IEVAP} VALVEAIR CLEANERRESONATORPOSITIVE CRANKCASE VENTILATION {PCV} VALVEEVAPORATIVE EMISSION IEVAP) PURGE CONTROLSOLENOID VALVEEVAPORATIVE EMISSION IEVAPI CONTROL CANISTEREVAFORATIVE EMISSION IEVAP} TWO WAY VALVETHREE WAY CATALYTIC CONVERTER (TWC'
{M/T}
i@l: F@i
HiiFl
(A/T)
I ENGINE I
I coor-rruri
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11-22

System Description
Vacuum Connections (cont'dl
D16Y8 engine l'99 - 00 modetsl:
(]-i PAIMARY HEATEO OXYGEN SENSOR {PRIMARY HO2S,SENSOR 1)..2r SECONOARY HEATEO OXycEN SENSOB ISECONDARYHO2S, SENSOR 2li3) MANIFOLD ABSOLUTE PBESSURE {MAPI SENSORO ENGINE cooLANT TEMPERATURE (ECTI sENsoR(5) INTAKE AIR TEMPERATURE {IAT} sENsoRG] KNOCK SENSOR IKSI?r CRANKSHAFT SPEEo FLUCTUATTON {CKF) SENSOR.O IDLE AIR coNTRoL {IAc)vALvEi-9] THROTTLE BOOY {TB)(O FUEL INJECToRI]'i FUEL FILTER.O FUEL PRESSURE REGULAToR[t FUEL PUMP {FPl.D FUEL TANKil' AIR CLEANERTD RESONATORO FUEL TNJEC oN AtR tFtA) coNTRoL vAt_vE.19 POSITIVE CRANKCASE VENTILATION {PCVI VALVE
.19) EVAPORATIVE EMIssIoN {EVAP) PURGE coNTBoLSOLENOID VALVE€g PURGE JorNTtj EVApoRATtvE EMtsstoN {Evap} coNTRoL cANtsTERC4 EVAPONANVE EMISSION (EVAP) BYPASS SOLENOIDVALVE
?3 EVAPORATIVE EMISSION {EVAP} CONTROL CANISTERFILTERA4 EVAPoBATIVE EMIssIoN (EVAP) coNTRoL CANISTERVENT SHUT VALVEC! FUEL TANK PRESSURE sENsoREO EVAPOBATIVE EMISSION (EVAP) TWO WAY VALVEe? oNBoARD REFUELtiIG vApoR REcovERy {oRvR} VENTSHUT VALVE@ oNBoARD REFUELTNG vapoR REcovERy (oRvR) vapoRRECIRCULATION VALVEiP THREE WAY CATAI.YTIC CONVEBTER {TWCI
'- *o'*- -
COOLANT
]L
nrl
L
ii8'x'", *
--j IIM TTI ^n 14 [l(2i)-fr l-1ry|
11-24

|-
DI6YTengine('96mode|.,97coupe:KA,Kcmode|s,,97sedan:KA,KC,KL{Dx}modets,'gThatchback:a||models}:
COOLANT
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a:!)
o-o
aroa1t
PRIMARY HEATED OXYGEN SENSOR (PRIMARY HOzS,
SENSOR 1)SECONDARY HEATED OXYGEN SENSOR {SECONDARY
HOzS, SENSOR 2)
MANIFOLD AESOI-UTE PRESSURE IMAP) SENSOR
ENGINE COOLANT TEMPERATURE IECT) SENSOR
INTAKE AIR TEMPERATURE (IAT} SENSOR
CRANKSHAFT SPEED FLUCTUATION (CKF) SENSOR
IDLE AIR CONTROL (IACI VALVE
THROTTLE BOOY (TB)
FUEL INJECTORFUEL FILTERFUEL PRESSURE REGULATOR
FUEL PUMP IFPIFUEL TANKFUEL TANK EVAPORATIVE EMISSION (EVAPI VALVE
AIR CLEANERRESONATORPOSITIVE CRANKCASE VENTILTATION IPCVI VALVE
EVAPORATIVE EMISSION (EVAP} PURGE CONTROL
SOLENOID VALVEEVAPORATIVE EMISSION (EVAP) CONTROL CANISTER
EVAPORATIVE EMISSION IEVAPI TWO WAY VALVE
THREE WAY CATALYTIC CONVERTER (TWCI
[3)@ao(o
a@
(0
@)
(cont'd)
11-25

I
a
System Description
Vacuum Connections (cont'd)
816A2 engine:
@ EvApoRATtvE EMtsstoN tEvAp) puRGE coNTRoLSOLENOID VALVE@ PURGE JoINT€t EvApoRATtvE EMtsstoN (EVApt coNTRoL caNtsTERQA EVAPORATIVE EMISSION (EVAP) BYPASS SOLENOIDVALVE
@ EVApoRATtvE EMtsstoN lEvApl coNTRoL caNtsrERFILTER@ EvApoRATtvE EMtsstoN {EvApt coNrRoL cANtsrERVENT SHUT VALVE@ FUEL TANK PRESSURE sENsoRGI EVAPORATIVE EMISSION (EVAP} TWO WAY VALVE@ ONBOARD REFUETING VAPOR RECOVERY {ORVR} VENTSHUT VALVE@ oNBoAnD REFUELING vApoR REcovERy (oRvRl vApoR. RECIRCULATION VALVE(c} THREE WAY CATALYTIC CONVERTER {TWCI
(' PRIMARY HEATED OXYGEN SENSOR IPRIMARY HO2S.SENSOR 1l.?) SECONDARY HEATED OXYGEN SENSOR {SECONDARYHO2S, SENSOR 2)13] MANIFOLD ABSoLUTE PRESSURE (MAP) sENsoBi' ENGINE COOLANT TEMPERATURE IECT) SENSORO INTAKE AIR TEMPERATURE ITATI SENSORi6l KNOCK SENSOR {KS}O oRANKSHAFT SPEED FLUCTUATIoN {cKF} sENsoR@ IDLE AIR coNTRoL (IAc} VALVE€) THRoTTLE BoDy trB|(D FUEL INJECToRO FUEL PULSATIoN DAMPER[D FUEL FILTER@ FUEL PRESSURE REGULAToR!I FUEL PUMP IFP)f,' FUEL TANK(iD ArR CLEANERt' RESONAToR'.1]i POSITIVE cRANKcAsE VENTILATIoN {Pcv} VALVE
11-28

DataDescriotion
Loop status is indicated as "open" or "closed"'
Closed: Based on the HO2S output, the ECM/PCM deter-
mines the airlfuel ratio and controls the amount of inject-
ed fuel.
Open: lgnoring HO2S output, the ECM/PCM refers to sig-
nals from the TP, MAP, and ECT sensors to control the
amount of injected fuel.
The air/fuel ratio correction coefficient for correcting the
amount ot injected fuel when H02S feedback is in the
closed loop status When the signal from the HO2S is
weak, short term fuel trim gets higher, and the ECM/PCM
increases the amount of injected fuel The airlfuel ratio
gradually gets richer, causing a higher HO2S output
Consequently, the short term fuel trim is lowered, and
the ECMiPCM reduces the amount of injected fuel
This cvcle keeps the airlfuel ratio close to the stoichio-
metric ratio when in closed loop status'
Operating ValueF eeza Data
HO2S
Feedback
Loop Status
At idle speed: closed
YES
Short Term
Fuel Trim
! 20%
YES
Long Term
Fuel Trim
Long term fuel trim is computed from shon term fuel
trim and indicates changes occurring in the fuel supply
svstem over a long Period
lf long term fuel trim is higher than 1.00, the amount of
injecGd fuel must be increased. lf it is lower than 1 00'
the amount of injected fuel must be reduced'
! 20%
YES
lntake Air
Temperature
{IAT)
The IAT sensor converts intake air temperature into volt-
age and signals the ECM/PCM. When intake air tempera-
ture is low, the internal resistance of the sensor
increases. and the voltaqe signal is higher'
With cold engine:
Same as ambient temPer'
ature and ECTYES
At idle speed:
approx. 10 %YESThrottle
Position
Based on the accelerator pedal position, the open'ng
angle of the throttle valve is indicated
lgnition
Timing
lgnition timing is the ignition advance angle set by the
gCV/eCV. tn" gCU/PCM matches ignition timing to the
driving conditions.
CLV is the engine load calculated from the MAP data'
At idle speed: 12'i 2'
(81642 engine: 16" t 2")
BTDC with the SCS ser-
vice connector connected.
NO
Calculated
Load Value
{CLV)
At idle speed:
15-35%
At 2.500 rpm with no load:
12 - 30%
YES
ro
11-87