d16y5 HONDA CIVIC 1998 6.G Workshop Manual

Emission Gontrol System
System Description
The emission control system includes a Three Way Cata-lytic Convener (TWC), Exhaust Gas Recirculation (EGR)
system,. Positive Crankcase Ventilation (pCV) system andEvaporative Emission (EVAP) Control system. The emis-sion control system is designed to meet federal and stateemission standards.*: D16Y5 engine
Tailpipe Emission
Inspestion
@@ Do not smoke during ihis procedure. Keepany open flame away from your work area.
1. Start the engine. Hold the engine at 3,000 rpm withno load (in Park or neutral) until the radiator fancomes on. then let it idle.
2. Connect a tachometer.
Check and, if necessary, adjust the idle speed (see
page 11-220 - 223).
Warm up and calibrate the CO meter according to themeter manufacturer's instructions.
Check idle CO with the headlights, heater blower,rear window defogger, cooling fan, and air condition-er off.
NOTE: (Canada) Pull the parking brake lever up.Start the engine, then check that the headlights areoff.
CO mete. should indicate 0.1% maximum.
NOTE: '98 Dl6Y5 engine - lf the idle speed incress-es to 8101 50 rpm, this means the EVAp system ispurging the canister. To stop the purging temporari-ly. raise the engine speed above 1,000 rpm with theaccelerator pedal, then slowly release the pedal.
11-252
eFORWARD -
Three Way Catalytic Converter
(TWCI
Doscription
The Three Way Catalytic Converter (TWC) is used toconven hydrocarbons (HC), carbon monoxide (CO), andoxides of nitrogen (NOx) in the exhaust gas to carbondioxide (COr), dinitrogen (N,) and water vapor.
D15Y5, D16
, engine:
'99 - 00 D16Y8, 81642 engine:
ENGINE SIDE
t

Emission Control System
Exhaust Gas Recirculation (EGR) System (D16Y5 engine with GWI (cont'dl
lTl49il T_he scan tool indicates Diagnostic Trouble Code (OTC) P1491: A malfunction in the Exhaust Gas Recirculation- lEgh) svstem.
CvT lM/T see page 1l-2611:
J
EGR VALVELIFT SENSOR#16 HOSE
PUMP/GAUGE,0- 30 in.HsA973X-041-XXXXX
EGRVALVE
The MIL has been reoorted on.DTC P1491 is stoled.
Problem verification:1. Do the ECM/PCM Reset Proce-du re.2. Connect the SCS service con'
3. Start the engine. Hold theengine at 3,000 rpm with noload {in Park or neutral) untilthe radiator fan comes on,4. Drive the vehicle on the roadfor approx. 10 minutes. Try tokeep the engine speed in the1,700 - 2,500 rpm range.
Intermittonl failure, system is OKat this time. Check for Door con-nections or loose wires at, C144{EGR velve} and ECM/PCM.
ls DTC P l49l indicated?
Check fo. vacuum to ihe EGR
1. Disconnect the No. 16 hose fromthe EGR valve.2. Connect a vacuum pump/gauge to the hose.3. Start the engine and let it idle.
ls there any vacuum?
Check tor a malfunction in theEGR control solenoid valve:'1. Disconnect the EGR controlsolenoid valve 2P connector,2. Becheck the No. 16 hose for
Check vacuum hose routing o,the entire EGR svstem. lf hoserouting is OK, replac€ the EGRcontrol solenoidvalv6.
ls there any vacuum?
Substitute a known-good ECM/PCM and recheck. It symptom/indicalion goes away, replacethe original ECM/PCM.
(To page 11 257)
11-256

\JExhaust Gas Recirculation System (D16Y5 engine with M/T)
M/T:
EGR VALVE 6P CONNECTOB (C14'rl
G10lIBLK}
1
a
PNK
IE.EGRI
Wi16 side of male terminals
I
sG2{GRN/BLK}
vcc2{YEL/BLU)
- Th6 MIL ha3 b€on reponed on.- DTC Pl,{tl is 3tored.
Prcblem verification:1. Do the ECM Reset Procedure.
2. Connect the SCS service con_nector.3. Start the engine. Hold the
engine at 3,000 rpm with no
load (transmission in neutral)
untilthe radiator fan comes on.
4. Drive the vehicle on the road
for approx. 10 minutes. Try to
keep the engine speed in the
1,700 - 2,500 rpm range.
lnlermittont tailure, svalem is OK
at thi3 tim6. Check foi Poor con'
nections or looso wiro3 at Cl/K
IEGR valvsl and ECM.
ls DTC P1491 indicated?
Check tor a malfunction in the
EGR valv6:1. Turn the ignition switch OFF.
2. Disconnect the EGR valve 6P
connector.3. Stanthe engine and let it idle
4. Measure voltage between the
EGR valve 6P connector termi'
nals No.4and No.6.
Check the EGR valve:1. Turn the ignition switch OFF2. Turn the ignition switch ON lll).3. Measure voltage between theEGR valve 6P connector termi
nals No.2 and No.3.
ls there battery voltage?
Substitute a known-good ECM
and recheck. It symptom/indica_tion goes away, replace th€ origi-
nal ECM.
ls there approx.5V?
(To page 11-262)

Emission Control System
(From page 11-261)
Check tor open in the wire (SG2
linel:Measure voltage between theECM connector terminals D10and D11.
Repsir open in lhe wire beiweenECM lOllland EGR valve.ls there approx. 5 V?
Check the EGR valve:1. Turn the ignition switch OFF.2, At the sensor side, measureresistance between the EGRvalve 6P connector terminalsNo. 1 and No. 2.
ls there continuity or resis-tance of 100 k0 or higher?
Check the EGR valve:Measure resistance between theEGR valve 6P connector terminals No. 1 and No.3.
ls there 100 k0 or higher?
Exhaust Gas Recirculation System (D16Y5 engine with M/T) (cont'dl
ECM CONNECTOR D {16P)
vcc2(YEL/BLU)
\v
sG2IGRN/BLK)
Wire side of female term;nals
EGR VALVE 6P CONNECTOR
EGR L(WHT/
BLK}
SG2 (GRN/BLK)
Termanal side of male terminals'l'
EGR L{WHT/BLK}
vcc2
{YEL/BLU}
(To pase 11 263)
1-262

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Exhaust Gas Recirculation System
The scan tool indicates Diagnostic Trouble
Recirculation (EGRlvalve lift sensor circuit.
(D16Y5 enginel
Code {DTC) P1498: A high voltage problem in the Exhaust Gas
EGR VALVE LlFf SENSOR 3P {M/T: 6Pl CONNECTOR (C1441
cvT:
vcc2{YEL/BLUI
SG2 IGRN/BLK)
IM/T:sG2{GRN/BLKI
Wir€ side ol lemale terminals
ECM CONNECTOR D (16P)
vcc2(YEL/BLUIsG2(GRN/BLK)
Wir€ side of female terminals
PCM CONNECTORS C 131P)'
Wire side oI female terminals
11-265
- The MIL has been reportod on.- DTC P1498 is storod.
Probl€m verification:1. Do the ECM/PCM Reset Proce
dure.2. Stan the engine.
Intermittent tailure, sy3lem is OK
at lhis time. Check tor poor con'
nections or loose wire3 at C144
|EGR valvel and ECM/PCM.
ls DTC P1498 indicated?
Check for an open in tho EGRvalv6 lift sen3or:1. Turn the ignition switch OFF.
2. Disconnect the EGR valve lift
sensor 3P (M/T: 6Pl connector.
3. Turn the ignition switch ON (ll).
4. Measure voltage between the
EGR valve litt sensor 3P lM/T:6P) connector terminals No. 3and No.2.
ls there approx.5 V?
Check lor op€n in th€ wire (SG2
line):Measure voltage between ECM/PCM connector terminals 010 andD1l (C18 and C28)*.
Repair open in tho wiro betwoen
ECM/PCM lDl1 (Cl8)r) and EGR
valvo lift sensor.ls there approx. 5 V?
Substitute . known-good ECM/PCM and recheck. ll symptom/indicrtion goes away, replacothe original ECM/rcM.
*:'99 - 00 D16Y5 engine with CVT

Emission Control System
Positive Crankcase Ventilation IPCVI System
Descripiion
The Positive Crankcase Ventilation (PCV) system 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 manifold vacuum
and the blow-by gas is drawn directly into the intake
manifold.
D15Y5, D16Y8, 816A2 ongins:
BREATHERHOSE
Dl6'|11 6ngin6:
-: aLOW-BY VAPOR-: FnESH AIF
11-266
tJ
lrcpection
1. Check the PCV hoses and connections for leaks and
clogging.
2. At idle, make sure there is a clicking sound from the
PCV valve when the hose between the PCV valve
and the intake manifold is lightly pinched with your
fingers or pliers,
D16Y5, D16Y8 ongins:
BREATHERHOSE
PCV VALVE
Gently pinch here.
Bl6A2 engins:VALVE
lf there is no clicking sound, check the PCV valve
grommet for cracks and damage. If the grommet is
OK, replace the PCV valve and recheck.
PCV

1\
Evaporative Emission (EVAPI Controls
Description
The evaporative emission controls are designed to minimize the amount of fuel vapor escaping to the atmosphere. The
system consists of the foliowing components:
A. Evaporative Emission (EVAP) Control Canisto]
An EVAP control canister is used for the temporary storage of fuel vapor until the fuel vapor can be purged from the
EVAP control canister into the engine and burned.
B. Vapor Purge Control System
EVAP control canister purging is accomplished by drawing fresh air through the EVAP control canister and into a port
on the intake manifold. The purging vacuum is controlled by the EVAP purge control solenoid valve.
I'96 D16Y5 engine,'96 Dl6Y7 engine,'96 D16Y8
engine (sedan),'97 D16Y5 engine,'97 D16Y7
engine (couper KA, KC models, sedan: KA, Kc'
KL iDX) models, hatchback: all models), '97
D 16Y8 engine (sedan: KA, KC models)l
I'96 D16Y8 engine (coupe),'97 D16Y7 engine
(coupe: KL model, sedan: KL (LX) model)"97
D16Y8 engine (coupe: all models, sedan: KL model)'98-all models,'99-all models,'00-all modelsl
I
c.
D.
or
l'lc COMPRESSOR CLUTCH ON
and
INTAKE AIR TEMPERATURE ABOVE 160"F (41'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 of fuel vapor to the EVAP control canister.
Onboard Refueling Vapor Recovery (ORVRI System {'99 - 00 models}
During refueling. the oRVR {onboard Refueling Vapor Recovery) vent shut valve opens with the pressure in the fuel
tank. and feeds the fuel vapor to the EVAP control canister.
t(cont'd)
11-267
EVAP PURGE CONTROL SOLENOID VALVE DUTY CON-
TROLLED AFTER STARTING ENGINE
ENGINE COOLANT TEMPERATURE ABOVE 154'F {68"C)
INTAKE AIR TEMPERATURE ABOVE 32'F (O'C)
and
VEHICLE SPEED ABOVE O MILE (O KM/h}
ENGINE COOLANT TEMPERATURE ABOVE 154'F (68'C)

Emission Control System
Evaporative Emission IEVAPI Controls (cont'd)
'96 D16Y8 ongins (coupol.'97 D16Y8 €ngino (coups: all mod€ls, sedan: KL model),'98 D16Y5 engine (all mod6lsl,'98
Dl5YB engine {all modols):
{BLK/YEL
From
< No. 15
FUELTANKPRESSURESENSOR
EVAP PURG€CONTROLSOLENOID VALVE
. LT GRN
GRN/BLK
ALTERNATORSP SENSOR(7.5 A)
VARIOUSSENSORS
YEL/BLU
V€NT SHUT
EVAPBYPASSSOLENOIDVALVEL BLU
WHTRED/YEL
L __ LT GRN/
EVAPTWO WAYVALVE
INTAKEMANIFOI.I'
'97 D16Y7 engin. (coupa: KL model, sedan: KL {LX) model},38 Dl6
/ engine:
?:y- -<
FromNo. 15ALTERNATORSP SENSOR17.5 A)
FUELTANKPRESSURESENSOR
YEL/BLULT G]GRN/BLK
LT GRN/WHT
BLU
YEL
EVAPBYPASSRED/
VALVE
EVAPTWO WAVALVE
EVAP CONTROLCANISTER
FUEL FILLCAP
BLK
11-268
FUEL TANK

\J
\
,96 D16Y5 engine,,96 D16r,gngino,,96 Dt6Y8 engine {3edan)' 37 D16Y5 engino..97 D16r, engine {coupe: KA, Kc mod-
els. sedan: KA, KC, KL {DX} models. hatchback: all modols}''97 Dl6Y8 ongine (s€dan: KA' KC mod€lsl:
The scan tool indicates Diagnostic Trouble code (DTC) P0441: Evaporative Emission (EVAP) control system
insufficient purge flow.
Description
By monitoring the purge line vacuum with the MAP sensor, the ECM/PCM can detect insufficient EVAP control system
purge flow.
Possible Cau3e
. EVAP Purge Control Solenoid Valve
. EVAP Purge Control Solenoid Valve Circuit
. EVAP Control Canister
. Vacuum Lines
. ECM/PCM
Troubl93hooting Flowchart
Wire side of femaleterminals
EVAP PURGE CONTROI-sottNotD vALvE 2P
CoNNECTOR (Cl1al
r-+-r
I'l'l
lG-ro.*l'rr"r
O)
Y
(cont'd)
11-271
- The MIL has bsGn.eportad on.- DTC milal k rtored.
Pioblem vsrificJtion:1. Start the engine. Hold the
engine at 3,000 rPm with no
load {in Park or noutral) until
the radiator fan comes on.
2. Do the ECM/PCM Reset Proce'
dure,3. Connect the SCS service con-
nector.4. Test-drive under following con-
ditions on the road- Without any electrical load- A/T in E or E Position(M/T in 3rd-sth gear)- Engine sPeed betweon
1,200 - 2.400 rpm.- Decelerate {rom 50 mph (80
knl/h)to 15 mph (24 km/h)lntormittont lailuro, sFtorn b OK
at thi. timo. Ch€ck tor Poor con'
ncction3 or looac wir.3 at C144
{EVAP purgo control tolonoid
vrtv.l .nd ECir/FCttl.
ls DTC P0441 indicatod?
Ch.ck fo. !n op€n in the wiro l|(illinel:1. Turn the ignition switch OFF.
2. Disconnect the EVAP Purgecontrol solenoid valve 2P con_
neclor,3. Turn the ignition switch ON (ll)
4. Measur€ voltage between bodyground and the EVAP Purgecontrol solenoid valve 2P con-
nector terminal No 1.
Rop.ir opor in tho wir6 b€two€n
the EVAP purgo codtiol tolonoid
v.lvo rnd tho No 15 ALIERNA'
TOR SP SENSOR 17.5 A)lu.o.
{To page 11-272)

J\
(From page 11-272)D16Y5 engine:
JUMPER WIRE
D16Y7, D16Y8 engine
VACUUMPUMP/GAUGE,
VACUUMPUMP/GAUGE,0 - 30 in.HgAs73x - 0il1 -
xxxxx
0 - 30 in.HgA973X -
otl -
xxxxx
I
EVAP CONTROLCANISTER
ECM/PCM CONNECTOH D I32PI
VACUUM/PBESSUREGAUGE0-4in.Hg07JAZ - 0010008
Wire side otfemale terminals
D16Y7, Dl6Y8 engine:
t
VACUUM/PRESSUREGAUGE0-4 in.Hgo?JAZ - 001fl)OB(cont'd)
11-273
PGl IBLKI
Check lhe EVAP Purge control
solsnoid valve:
1. Disconnect the vacuum hose
from the EVAP controlcanister'
2. Connect the vacuum PumP to
the hose and aPPIY vacuum
Does it hold vacuum?
Check the EVAP control canister:
1. Reconnect the vacuum hose to
the EVAP control canlster.
2. Connect the vacuum/Pressuregaugeto the Purge aar hose
3. Connect ECM/PCM connector
terminals A15 and A10 with a
iumper wire.4. Start the engine5. Check the vacuum
Check the EVAP two way valve(see page 11-193)
Does the EVAP two waY valveReplace the EVAP two wsY valve.
Sub3titute a known-good ECM/
PCM .nd recheck. lt symPtom/
indicrtion go6s away, rePlace the
original ECM/PCM.
D16Y5 sngin€: