Valve HONDA CIVIC 1998 6.G Workshop Manual

IThrottle BodY
Description
The throttle bodY is either a single-barrel side-draft type
(D16Y5, D16Y8, 816A2 engine) or a down-draft type
(D16Y/ engine). The lower portion ot the throttle valve is
heated by engine coolant from the cylinder head' The
idle adjusting screw which regulates the bypass air is
located on the top of the throttle body
THROTTLEPOS|T|ON lTPlSENSOR
IDLE AD.'USTINGSCREW
t
In3pection
1. Check that the throttle cable operates smoothly
without binding or sticking.
lf there are any abnormalities, check for:
. Excessive wear or play in the throttle valve shaft'
. StickY or binding throttle lever at the fully closed
Position.. Clearance between throttle stop screw and throt-
tle lever at the fully closed position'
D16Y5, Dl6Y8 engine:
THROTTLE STOP SCREW
{Do not adjust.)
Dl6Y7 ongine:
816A2 engins:
THROTTLE LINK
STOP SCREW
THROTTTE STOP SCREW(Do not adjust.)
Replace the throftle body if thsre is excessive play in the
throttle valve shaft or iJ the shaft is binding or sticking'
(cont'd)
11-247
{Do not adjust.)

Intake Air System
Fuel Injection Air (FlA) Controt System I'99 - 00 Dl6yg enginel
Dsscription
When the engine running lengine coolant below 149oF (6S"C)], the fuel Injection Air (FtA) Control Valve sends intake air tothe fuel iniectors.
E> : INTAKEAIR
FUELINJECTOB
11-250

\J
Fuol Iniection Air {FlA) Contlol Valve T$ting
1. Start the engine.
2. Remove the vacuum hose from the fitting on the
intake air duct, and connect a vacuum gauge to the
nose.
NOTE: Engine coolant temperature must be below
149"F (65"C).
VACUUM PUMP/GAUGE,
0-30 in.Hg.A973X - 041 -XXXXX
Raise and lower the engine speed, and make sure
the vacuum gauge reading changes as the engine
speed changes.
lf vacuum reading does not change check these
rtems:
. The vacuum lines of FIA system for misrouting,
leakage, breakage and clogging.
. The FIA controt valve for cracks or damage
. The cooling system (see section 10).
Hold the engine at 3,OOO rpm with no load (in Park
or neutral) until the radiator fan comes on, th€n let
it idle and recheck.
lf vacuum reading changes check these items:
a The FIA control valve for cracks or damage.
. The cooling system (see section 10).
11-251

Emission Control System
Exhaust Gas Recirculation (EGR) System (D16yS engine)
Doscription
The EGR system is designed to reduce oxides of nitrogen emissions (NOx) by recirculating exhaust gas through the EGRvalve and the intake manifold into the combustion chambers. lt is composed of the EGR valve. EGR vacuum conrrot vatve.EGR control solenoid valve. ECM and various sensors.The EcM contains memories for ideal EGR valve lifts for varying operating conditions, The EGR valve lift sensor detectsthe amount of EGR valve lift and sends the information to the ECM. The ECM then compares it with the ideat EGR valve liftwhich is determined by signals sent from the other sensors. lf there is any difference between the two. the EcM cuts cur-rent to the EGR control solenoid valve to reduce vacuum applied to the EGR valve.
EGR CONTROLCVT: SOLENoID vALvE
EGN VALVE LIFT SENSOR
BLK
I
I
11-254

4
The scan tool indicates Dlagnostic Trouble cod€ {DTc} Po4ol: lnsufficient flow in the Exhaust Gas Recirculation
(EGR) svstem.
Doscription
Deterioration (clogging, leakage, etc.) in the EGR line or EGR valve is detected by means of the changes in MAP before
and after the operation of the EGR valve.
lf deterioration has been detected during two cons€cutive driving cycles, the MIL will come on and DTC P0401 will be
stored.
Po$ible Causeg
. Clogging. leakage in the EGR line
. Faulty EGR valve
Troubleshooting Flowchart
\
- Tho MIL ht! bacn rgportod on.- DTC m40l is 3torod.
Problom vorification:
1. Do the ECM/PCM Reset Proce-
dure.2. Connect the SCS service con-
nector,3. Tost-drive under the following
conditions.- Without any electrical load- Decelerate lrom 55 mPh(88 km/h)lor at least 5 sec-
onos
lntormiftam f!ilu.a, ayltam ia OK
.t thb time,
- Clo.n tho inttkc mlnifold EGRport wittr carbursto. clotner.- Cl.an the pa$lgo insido tho
EGR valvo with crrburator
cloanol or aoglaca tha vllvo.

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

\EGR VALVELIFT SENSOR#16 HOSE
I
(From page 11-256)
EGR VALVE LIFT SENSOR3P CONNECTOR lC14.l)
zF vcczI- . ] IYEL/BLU)ll 2l3l---l-r_ 7 |
v-,, ISG2IGRN/BLK) I ^ II{Vts
ECM CONNECTOR D {16P)
PUMP/GAUGE,0 - 30 in.Hs4973X-041-XXXXX
sG2(GRN/BLKIvcc2IYEL/BLU}
Wire side ol temale terminals
PCM CONNECTORS C (31P}'
YES
Wire side of female terminals
1
(cont'd)
1-257
Check fo. a mallunction in theEGF valv€:1. ldove the vacuum pump/gauge
to the EGR valve.2. With the engine at idle, apply
26.7 kPa (200 mmHg,8.0 in.Hg)
ofvacuum to the EGR valve.
Does the engine stall or runrough and does the EGR valvehold vacuum?
Check for an open in the wire
IVCC2linel:1. Turn the ignition switch OFF.2. Disconnect the EGR valve liftsensor 3P connector.3. Turn the ignition switch ON (ll).
4. Measure voltage between theEGR valve lift sensor 3P con'
nector terminals No. 3 and
No.2.
ls lhere approx.5 V?
Check for an oDen in the wire
{VCC2 line}:Measure voltage between theECM/PCM connector terminalsD10 and Dl1 (C18 and C28)*.
Rep.ir open in the wire betweenrhe EGR valve snd ECM/PCM
{Dl0 {C28)*).lsthere approx.5 V?
Sub3titute t known-good ECM/PCM end recheck. lt 3ymptom/indication goos eway, replaceth6 original ECM/PCM.(To page 1l-258)*: '99 - 00 models

Emission Gontrol System
Exhaust Gas Recirculation (EGRI System (Dl6Y5 engine with CW) (cont'dl
EGR VALVE LIFT SENSOR3P CONNECTOR {Cl251
./
EGR L(WHT/BLKI
EGR LIWHT/BLKI
EGR L{WHT/BLKI
sG2
{GRN/BLK}
sG2{GRN/BLK}
Terminal side ol male terminal
ECIT'I CONNECTOR D II6PI
Wir€ side of f€male terminals
PCM CONNECTORS C (31PI*
{To page 11-259)
11-258
{From page 11-257}
Chock lor an opcn or short in th.EGR v.lve lift .€nsor'1. Turn the ignition switch OFF.2. At the sensor sid€, measur€resistance between the EGRvalve lift sensor 3P connectorterminals No. 1 and No.2.
ls there continuity or resis'tance ot 100 k0 or higher?
Chock tor sn op€n or lhort in theEGR valve lift lonror:Measure resistancg between theEGR valve lift s€nsor 3P connec-tor terminals No. 1 and No. 3.
ls there 100 k0 or higher?
Ch.ck tor an ooon or rhon in thcwiro IEGRL linc):1. Beconnect tho EGR v6lve liftsensor 3P connector.2. Turn tho ignition switch ON (ll).
3. Measure voltage between theECM/PCM connector terminalsD9 and Dl1 (C6 and C18l*.
ls there approx. 1.2 V?
(To page 11-259)
Wire side of female terminals

I
I
Wire side of lemale terminals
PCM CONNECTORS C (31P)*
ECM CONNECTOR O {I5PI
Wire side of temale terminals
t
(From page 11-258)
Check for a 3hort in the wire
{EGRL linel:Check for continuity betweenECM/PCM connector terminal Dg
Repair op€n in the wire betweenth6 EGR valve and the ECM/PCM(D9 tc6trt.
ReDair short in the wirc batweonthe EGR valve and ECM/PCM {Og(c5t*).
(From page 11-258)
11,260)
Check ths vacuum routing:'1. Recon nect the vacuumpump/gauge to the No. 16hose.2. Start the engine and let it idle.3. At the EGR control solenoidvalve side, connect the bat-tery positive terminal to theEGR control solenoid valveconnectot terminal No. 1.4. While watching the vacuumgauge, connect the batterynegative terminal to the EGRcontrol solenoid valve 2P con-nector terminal No. 2,
ls there approx.26.7 kPa
1200 mmHg,8.0 in.Hg) ofvacuum within 'l second?Chock the vlcuum hos6s:1. Turn the ignition switch OFF.2. Inspect the No. 16 and No. 10hoses for leaks, restrictions ormtsrouUng.
EGR CONTROL SOLENOID VALVE
2P CONNECTOR
Terminal side oImale lerminals
(cont'd)
11-259

Emission Control System
Exhaust Gas Recirculation (EGR) System (Dl6Y5 engine with CW) (cont'dl
tJ
(From page 11-259)EGR CONTROL SOLENOIDVALVE 2P CONNECTOR {C142}
Wire sideof lemaleterminals
ECMCONNECTORa t32Pl
Chock lor an open in the wire (E
SOL linsl:1. Turn the ignition switch OFF.2. Disconnect the 2P connectorIrom the EGR control solenoid
3. Disconnect the ECN4/PCM con-nector A (32P) (B (25P))* fromthe EcM/PCM.4. Check tor continuity betweenECM/PCl, connector terminal47 (86)* and the EGR controlsolenoid valve 2P connectorterminal No.2.
Repair opon in th. wir. bstwocntha EGR control 3ol€noid valvoand tho ECM/PCM (A7 186l'1.
ls there continuity?
Check for . rhort in the wire(ESOL linel:Check for continuity between theEGR controlsolenoid valve 2P con-nector terminal No. 2 and bodyground,
R.p.ir ahort in tha wi.c b.twecnthe EGR control iolonoid vllyeand th. ECM/FCM {A7 (46}rl.
Check for an opon in the wiroIGND linel:Check for continuity between theEGR controlsolenoid vaive 2P con-nector terminal No. I and bodyground,
Rcpai. op€n in the wir6 b6'twoenthe EGR control rol.noid valveand G101.
Sub3titule a known-good ECM/PCM and rechock. lf symptom/indication goes away, replac€the original ECM/PCM.
ESOL
IRED)
ESOLIRED)
Wire sideof femaleterminals--_-]
I
EGR CONTROL SOLENOIDVALVE 2P CONNECTOR ICl'2}
Wire sideof femaleilterminals
ECMCONNECTORB l25P)ESOL(REDI
Wire sideof femalerermtnats
*: '99 - 00 models
11-260