1998 HONDA CIVIC mount

PGM-FI System
System Description (cont'dl
Lean Burn Control {D16Y5 engine: CvT)
The lean burn control system is based on the characteristic increase in crankshaft angular acceleration which occurs inwhen the air-fuel ratio gets leaner.
The CKF sensor, which is mounted on the crankshaft, monitors sngine speed, lf crankshaft angular acceleration falls belowa certain level (target air-fuel ratio level), the amount of injected fuel is reouceo.
lf crankshaft angular acceleration exceeds this level. the amount of fuel is increased.
This system improves fuel economy and driveability by controlling the amount of injected fuel in the lean burn rangeimmediatelv before combustion starts to deteriorate.
1 1-1 06
TOC/CKP/CYP SENSOR
MAP SENSOR
CKF SENSOR
ECM
Comparison oI current airfuel ratio to target ratio

PGM-FI System
Random Misfire
lFoioo l*u o, [FTioo l*' *' and
The scan tool indicates Diagnostic Trouble Code (DTC)
P0300*5 or P1300*3 *1 and some of P0301 - P0304:Random misfire.Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensorwhich is attached to the crankshaft.
lf misfiring strong enough to damage the catalyst is detected. the MIL will blink during the time of its occurrence, and DTCP0300*5 or P1300*3'*' and some of DTCs P0301 through P0304 will be stored. Then, after misfire has ceased, the MIL willcome on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTCP0300*5 or P1300*3 *a and some of DTCS P0301 through P0304 will be stored.NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTC. troubleshoot those DTCS first, thenrecheck for the misfire DTC.
P0106*4. P0107. P0108, P1128*3 *5, Pl129*3 *5; MAP sensorP0131. P0132: HO2S
P0171, P0112i Fuel metering
P0401, P 1491, P1498: EGR svstem*1P0505: ldle Control SystemP1253: VTEC System*,P1361, P1362: TDC sensorP1381, Pl382: CYP sensorP1508: IAC valve
Possible Cause. Fuel pump insufficient fuel pressure, amount of flow. Fuel line clogging, blockage, leakage. Fuel filter clogging. Fuel pressure regulator stuck open. EGR system malfunction*1. Distributormalfunction. lgnition coil wire open. leakage *l: D16Y5 engine. lgnition control module malfunction *2: D16Y5, D16Y8, Bt6A2 engine. MAP sensor range/performance, poor response*r *3: '97 models. Valves carbon deposit *4;'96 models. Compression low *5: '98 - 00 models. IAC valve malfunctionr.. VTEC system malfunction*,. Fuel does not meet Owner's Manual spec., lackoffuel. HO2S. HO2S circuit
Troubleshooting
By test-driving, determine the conditions during which misfire occurs, Depending on these conditions, test in the orderdescribed in the table below.
Possible
- --^ ---
rage
causeEGR*1
system
Crankshaft
position (CKP)
sensor
Fuel
pressure
Distributor and
lgnition wirestcMClearance
tAc
ValveMAP
sensor
section 611-230,
231section 23section 23section 611-19411
Only low rpm and
loado@@oo
Only accelerating@o@@
Only high rpm and
toaooo@
Not specificoo@
NOTE: lf misfire doesn't recur, some possible causes are fuel that doesn't meet owne/s manualspec, lack of fuel, carbon deposits on spark plug, etc.
1 1-1 66
I
P0304

\Crankshaft Speed Fluctuation (GKFI Sensor .
firC- 48 Models, '99 - 00 D16Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P1336; Intermiftent interruption in the Crankshaft Speed
Fluctuation (CKF) sensor circuit.
ThescantooIindicatesDiagnosticTroub|ecode{DTC)P1337:NosignaIinthecrankshaftspeedF|uctuation(cKF}
sensor circuit.
D6scription
Thediagnosticsystemhasapu|serrotoronthecrankshaftandapu|sepick-upsensorontheengineblock.TheEcM/PcM
monitors the crankshaft speed ftuctuation based on the cKF sensor signal, and judges that 8n engine misfire occurred if
the fluctuation goes beyond a predetermined limit'
I
fPrk6l
lFr3g7-l
CKF SENSOR 3P CONNECTOR
L:l.)l l.' -Ir-T--T---.]l1 l2l3llL-''---r
CKFM I I CKFP
twrfit 1,.^ | lsLul\.7
Terminal side of male terminals
CKF MIWHT}
CKF PIBLUI
I(cont'd)
- The MtL hds been reported on.- DTC P1336 and/or P1337 a.e
stored.
P.oblem v€rific.tion:1. Do the ECM/PCM Reset Proce-
dure.2. Stan the enginelntormittont lailur6, tY3tom b OK
at thit tima. Chock tor Poor con'
nactions or loota wito! at C102
IC-KF son$rl .nd ECt /PCM, and
mrka suro CKF tonaor mounting
boh ittigM.
Chock for .n open in tho CKF aen-
30t:1. Turn the ignition switch OFF
2. Disconnect the CKF sensor 3P
connector,3. Measure the resista nce
between the CKF sensor 3P
connector terminals No. 1 and
No.3.
ls there 1.6- 3.2 kO?
Ch€ck tor a short in the CKF son'
30tiCheck {or continuitY between
body ground and the CKF sensor
3P connector termin6ls No. 1 and
No.3 individuallY.
(To page 11 184)
1 1-183

tCrankshaft Speed Fluctuation (CKF) Sensor -
('99 - 00 Mociels except D16Y5 engine with M/T)
The scan tool indicates Diagnostic Trouble code (DTC) P1336: Intermittent interruption in the crankshaft speed
Fluctuation (CKF) sensor circuit
The scan tool indicates Diagnostic Trouble Code (DTC) P1337: No signal in the Crankshaft Speed Fluctuation (CKF)
sensor circuat,
Description
Thediagnosticsystemhasapulserrotoronthecrankshaftandapu|sepick-upsensorontheengineb|ock.TheEcM/PcM
monitors the crankshaft speed fluctuation based on the cKF sensor signal. and judges that an engine misfire occurred if
the fluctuation goes beyond a predetermined limit'
I
Ftu6l
tF13g7l
CKF SENSOR 3P CONNECTOR
r--r t|-.r-r'--]llll l2l3ll.l---'.-T_
CKFM I I CKFP
twHTl |/Ai i lBlul--\9-
Terminal side oI male terminals
CKF M(WHT)CKF P(BLU)
t(cont'd)
1 1-185
- The MIL has b€on reportad on.- DTC P1336 and/or P1337 are
stored.
Problem verification:1. Do the ECM/PCM Reset Proce'
dure.2. Start the enginelntermittcnt failuro, sydcm is OK
ai this time. Check lot Poor con_
noctions or loo3e wiros at C102
ICKF s€nsor) and ECM/FCM, and
make suro CKF sansor mounting
bolt b tight.
Check tor an open in the CKF sen_
1. Turn the ignition switch OFF
2. Disconnect the CKF sensor 3P
3. Measure the resistance
between the CKF sensor 3P
connector terminals No. 1 and
No.3.
ls there 1.6 3.2 kO?
Check for a short in ihe CKF sen_
sot:Check for continuity betweenbody ground and the CKF sensor
3P connector terminals No 1 and
No.3 individuallY.
(To page 11-186)

ldle Control System
System Description
The idle speed ot the engine is controlled by the ldle Air Control (lAC) Valve.The valve changes the amount of air bypassing into the intake manifold in response to electric current controlled bv theECM/PCM. When the IAC Valve is activated, the valve opens lo maintain the proper idle speed.
D16Y5, D16Y8, Br6A2 engine (M/T):
(ROTARYItac vat-vEEI{GINEcooLAI{T
VARIOUSsEI{SORS
VARIOUSSENSORS
INTAKE MANIFOTDDl6Ys {CVTl, D16Y8 engine lA/T):
D16Y7 engine:
{ROTABY)
;iy--, - --- INTAKEMANIFOLD
11-190

1.After the engine starts, the lAc valve opens for a certain time. The amount of air is increased to raise the idle speed
about 150 - 300 rpm.
When the coolant temperature is tow, the IAC valve is opened to obtain the proper fast idle speed. The amount of
bypassed air is thus controlled in relation to the engine coolant temperature'
IOLE SPEED
lrpml
176
80
ENGI ECOOLANI TEMPERATURE
t" Fl
toc)
ll
't.Whentheid|espeedisoutofspeciiicationandthescantoo|doesnotindicateDiagnosticTroub|ecode(DTc)P0505
or P1508. check the following items:
. Adiust the idle speed {see page 11-220}
. Starter switch signal (see page 11-202)
. Air conditioning signal (see page l1-204)
. ALT FR signal (see Page 11-2081
' Brake switch signal (see page 11-210)
. PSP switch signal (excapt Canada model) (see page 11-212)
. A,/T gear position signal {see section 14, Dl6Y5 engine (CVT):
page 11-216). Clutch switch signal (D16Y5 engine with M/T) (see page 11-218)
. Hoses and connections
' IAC valve and its mounting O-rings
lf the above items are normal, substitute a known-good IAC valve and readjust the idle speed (see page 11-220)
|ftheid|espeedsti||cannotbeadjustedtospecification(andthescantoo|doesnotindicateDTcP0505orP]50S)
after IAC valve replacement. substitute a known-good ECM/PCM and recheck. lf symptom goes away, replace the
original ECM/PCM.

ldle Control System
ldle Air Control (lACl Vatve ('96 - 98 Dl6ys, Dl6yB engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P1508: A problem 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 inorder to maintain the proper idle speed.
IAC VALVE 2P CONNECTOR ICl3A)
,flrcerh-:J iYEL/BLKI
!.__-,/ -lt(v)
-T-=
Wire side of female terminals
tAcv(BLK/
ELUI
ECM CONNECTOR A I32PI
Wire side oI lemal€ terminals
VALVE
6a10ll12t3r5t6l7t8t920232a
t*25&a2A3o
The MIL hss b€on repo.ted on.DTC P'l508 i. itorod.
Problem vorification:1. Do the ECM/PCM Reset Pro-cedure,Start the engine, and warm ituP to normal operating tem-perature.
Intormittont t!llur., sy.tcm b OKat thb tim6. Chsck fol poor con-ncctionr or loo3e wirot at C138(lAC valv.l.nd ECM.
ls DTC P1508 indicated?
Check for an opcn in the wiro(lGPl line):1. Turn the ignition switch OFF.2. Disconnect the IAC valve 2Pconnector.3. Turn the ignition switch ON (ll).
4. Measure vohage between bodyground and the IAC valve 2Pconnectorterminal No. 2.
R.prir opan in the wiro botwa.nIAC valv..nd PGM-FI main r.l.y.
Chock for an opon or sho in thewire (IACV linal:1. Turn the ignition switch OFFand reconnect the IAC valveconnector.2. Disconnect the ECM connectorA (32P).
3. Turn the ignit;on switch ON (ll).4. Measure voltage betweenbody ground and ECM con-nector terminal A12.
(To page 1l-195)
11-194

ldle Gontrol System
ldle Air Control (lAG) Valve ('99 - 00 Dl6Y8 engine with M/T, Bt6A2 enginel
[Fl50g l ]h" scan tool indicates Diagnostic Trouble Code (DTC) P1508: A problem in the ldle Air Controt AC) vatve- CtrCUtt.
The IAC Valve changes the amount of air bypassing the throttle body in response to a current signal from the ECM inorder to maintain the proper idle speed.
IAC VALVE 2P CONNECTOR IC138'
la rcprI - {YEL/8LKI 2t--d,
Y-=
Wire side ot female terminals
Wire side of lemale terminals
VALVE
The MIL has boon r€oorted on.DTC P1508 is srored.
Probl6m verification:1. Do the ECM/PCM Reset Pro-cedure.2. Start the engine, and warm itup to normal operating lem-perature.
Intermittent tailure, system is OKat this timg. Check to. poor con-noctions or loose wires at C138{lAC valvel and ECM.
ls DTC P1508 indicated?
Ch6ck for an open in the wir€{lGPl lino}: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 2Pconneclor termina I No.2,
Repair opon in the wire bgtwoenIAC valve and PGM-Fl main relay.
Check tof an open or short in thewire {IACV line}l1. Turn the ignition switch OFFand reconnect the IAC valve
2. Disconnect the ECM connectorB {25P).3. Turn the ignition switch ON (ll).
4. Measure voltage betweenbody ground and ECM conn€ctor terminal 823.
(To page 11-197)
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