1998 HONDA CIVIC valve stem

PGM-FI System
Fuel Supply System
D017-il Th""""ntool indicates Diagnostic Troubte Code {DTC) p0171;Thefuet system istoo lean.
1P0172 | fne scan tool indicates Dlagnostic Trouble Code (DTC) P0172:Thefuel system istoo rich.
Description
By monitoring the Long Term Fuel Trim, long term malfunctions in the fuel system will be detected.lf a malfunction has been detected during two consecutive trips, the MIL will come on and DTC P0171 and/or P0172 will bestored.
NOTE: lf some of the DTCS listed below are stored at the same time as DTC P0171 andlot P0172, ltouhleshoot those DTCSfirst. then recheck for DTC P0l7l andlot P0172.
P0106-8, P1128*3. *5, P1129*3 *5 MAP Sensor
P0135; Primary HO2S Heater
P0137. P0138: Secondary HO2S
P0'141: Secondary HO2S Heater
P0401: EGR Flow Insufficient*1
P0441: EVAP System Insufficient Purge Flow*6
P1259: VTEC System*,
P1491:EGR Valve Lift Insufficient*r
P1498: EGR Valve Lift Sensor Hjgh Voltage*r
*r: D16Y5 engines*': Dl6Y5, D16Y8, 81642 engine*3: '97 models*a:'96 modelsf 5: '98 - 00 models*6: '96 D16Y5 engine,'96 D16Y7 engine,'96 D16Y8 engine (sedan),'97 D16y5 engine,,97 D16y7 engine (coupe: KA, KC mo+els, sedan KA. KC, KL (DX) models. hatchback; all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
DTC P0'171
loo lean
DTC P0172
too rach
Fuel Pump insuff icient f lovpressure
Fuel Feed Line clogged, leaking
Fuel Pressure Regulator stuck open
Fuel Filter clogged
Fuel Injector clogged, air inclusion
Gasoline doesn't meet Owner's Manual spec.
Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*.
EGR System malfunction (too much flow)*1
Valve Clearance
Exhaust leak
Fuel Pressure Regulator clogged, stuck closed
Fuel Return Pipe clogged
Fuel Injector leaking
Gasoline doesn't meet Owner's Manual spec.Primary HO2S (Sensor 1) deteriorated
MAP Sensor range/performance*a
EGR System insufficient flow*1
EVAP Purge Control Solenoid Valve leaking, stuck opened
Valve Clearance
11-164

t
Troubleshooting Flowchart
'l
NO
a-,-:- -
YES
- The MIL ha3 b€on rePorled on.- DTC P0171 a^dlot P0172 arc
stored,
is the fuel pressure OK?
Check the fuel pt€ssure regulator
and fusl re{urn pipe.ls the fuel pressure too high
ortoo low?
Check the Primary HO2S:
1. Start the engine. Hold the
engine at 3,000 rpm with no
Ioad (in Park or neutral) until
the radiator Ian comes on
2. Check the Primary HO2S(Sensor 1) output with the
scan tool,
Check the tu6l pump. fuel leedpipe, fu€l fiher, and Iuel Pressureregulator.
Does it stay at less than 0.3 V
or more than 0.6 V?
Check lor a sticking or leaking
EVAP purge control solenoid
With a vacuum PumP, aPPIY vacu-
um to the EVAP purge control
solenoid valve from the intake
manifold side.
Does it hold vacuum?
Check the MAP sensor outputr
1. Turn the ignition switch ON (ll)
2. Check the MAP with the scan
tool.
Check th6 response of the MAP
sensoa:1. Start the engine.2. Check the MAP with the scan
tool.
ls a MAP of 40.0 kPa 1300 mmHg,12.0 inHg) or less indicated within
one second after starting the
engine?
- Check th€ valve cloarance.- Check the EGR rystem lD16Y5enginel.- lf they are OK, r€place the tueliniocto]3.
1 1-165

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

I
Misfire Detected in One Cylinder
P0301 | The scan tool indicates Diagnostic Trouble Code (DTC) P0301: Cylinder 1 misfire detected.
[F03O2l 16"""untool indicates Diagnostic Trouble code (DTc) P0302: Cylinder2 misfire detected.
[FO3Ofl 16" ".un toot indicates Diagnostic Troubte Code (DTC) P0303; Cylinder 3 misfire detected.
I P0304 I ths..rr tool indicates Diagnostic Trouble Code (DTC) PO3O4: Cylinder 4 misfire detected.
D€scription
lMisfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensor
which 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 DTC
PO3O1, P0302, PO3O3 or P0304 will be stored. Then, after the misfire has ceased, the MIL will come on.
lf misfiring that increases emissions is detected during two consecutive driving cyclss, the MIL will come on, and DTC
P0301, P0302, P0303 or 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, then
recheck for the misfire DTC.
PO106*1, P0107, P0108. P1128*3'*5, P1129*3'*5: MAP sensor
P0131, P0132: HO2S
P0171, P0172iFuel suppiy system
P0335, P0336: CKF sensor
P0401. P1491, P1498: EGR system
P0441: EVAP system Insufficient purge flow*6
Pl359. P1361. Pl362: TDC sensor
P1381. Pl382: CYP sensor*o: '96 models*6: '96 D16Y5 engine,'96 D16Y/ engine,'96 D16Y8 engine {sedan),'97 D16Y5 engine,'97 D16\4, engine (coupe: KA,
KC models, sedan KA. KC, KL (DX) models, hatchback:all models),'97 D16Y8 engine (sedan: KA, KC models)
Possible Cause
. Fuel injector clogging, fuel leakage, air leakage
. Fuel injector circuit open or shorted
. Spark plug carbon deposits, fouling, malfunction
. lgnition wires open. leaking
. Distributor malfunction
. ComDression low
. Valve clearance out of spec
. VTEC system malfunction (D16Y5, D16Y8. 81642 engine)
. HO2S
. HO2S circuit
(cont'd)
11-167
r'a

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

ldle Control System
ldle ControlSystem
lF0505 l Th" """n tool indicates Diagnostic Trouble Code (DTC) PO5O5: tdte controt system malfunction.
NOTE: lf DTC P1508 or P1509 is stored at the same time as DTC P0505, troubleshoot DTC p1508 or p1bog first. thenrecheck for DTC P0505.
Possible Cause
. IAC valve mechanical malfunction
. Throttle body clogged pon, improper adjustment. Intake manifold gasket leakage
. Intake air hose loose leakage
. Vacu um leak
. ECT sensor incorrect output
. Throttle Position sensor incorrect output*r
Troubleshooting Flowchart
The MIL has been reoorted on.DTC P0505 is stored.
Problem verification:1. Start the engine. Hold theeng;ne at 3,000 rpm with noload (jn Park or neutral) untilthe radiator fan comes on, then*r let it idle.t2. with rhe scan toot, ct'eit Ge l
Throttle position should beapprox. 10% with the throttle fully closed.E ngine coolant tempera-ture should be 194 205'F(90 96.Ci.lf they are not within thespec., repair the faulty sen
L._ _9oI9[cr]41 l3. Chec& the engine speed atidle with no-load cond;tionsiheadlights, blower fan, reardefogger, radiator fan, and airconditioner are not operating\see page l1-22O - 223).
Intermittent tailure, system is OKat this time.ls the idle speed OK?
ls it 550 rpm or less?
(To page 11,193)
*1r'96 models only
11-192
(To page ll-193)

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)
1 1-1 96