1998 HONDA CIVIC Vacuum hose

\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 (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

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
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

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(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€:

Emission Control System
Evaporative Emission (EVAP) Gontrols (cont'd)
'99 - 0O models only:
The scan tool indicates Diagnostic Trouble Code (DTC) P0451: The Fuel Tank Pressure sensor circuit range/oerformance Droblem.
ECM/PCM CONNECTORS
wire side ot femare terminars sG2 IGRN/BLK)
FUEL TANKPRESSURESENSOR
VACUUMPUMP/GAUGE,0 - 30 in.Hg
FUEL TANKPRESSURE SENSORASSEMBLY
EVAP TWOWAY VALVE
IJ
tl'
Ths MIL has been reDortgd on.DTC m/$1 i3 stored.
Check the tuel tank pros3ure ser|-sor:1. Do the ECM/PCM Reset Proce-dure.2. Remove the tuellill cap.3. Turn the ignition switch ON (ll).4. N4onitor the FTP Sensor volt-age with the Honda PGMTester, or measure voltagebetween body ground andECN4/PCM connector terminalsA29 and C18.
ls there approx. 2.5 V7
Check tho tuel tank pressure !on-soa:1. Remove the fuel tank (seepage 11 2421.2. Remove the fuel tank pres-sure sensor assembly fromthe fueltank.3. Connect the fuel tank PressureSensor sub-harness 6P con-nector to the access panelside connector,4. Disconnect the hose betweenthe EVAP two way valvg andthe fuel tank pressure sensor atthe EVAP two way valve end.5. Connect a vacuum pump tothe open end ofthat hose.6. Turn the ignition switch ON (ll).7. Monitor the FTP Sensor volt,age with the Honda PGMTester, or measure voltagebetween ECM/PCM connectorterminals A29 and C18, andcarefully pump vacuum on thehose one stroke at a time.8. The voltage sho!ld smoothlydrop from the stading approx.2.5 V down to approx. '1.5 V.STOP applying vacuum whenthe voltage drops to approx. 1.5V or damage to the fuel tankpressure sensor may occur.
Does the voltage drop toapprox. 1.5 V and hold?
Sub3titute a known-good ECM/PCM and r6check. It symptom/indicltion 90e3 aw.y, replac\. th€original ECM/PCM.
A (32P)
A973X - 041 -
xxxxx
11-274

\
t,96 D16Y8 engine (coup6l,'9? Dl6Y7 engine (coupe: KL model, sedan: KL (LX) model)"g7 Dl6Y8 ongine (coupe: all mod-
els, sedan: KL model,'98-8ll modelsl 39 - 00 Dl5Y5 engine with M/Tl:
The scan tool indicates Diagnostic Trouble code (DTc) P1456: Evaporative Emission (EVAP) control system leak
detected (fuel tank sYsteml
The scan tool indicates Diagnostic Trouble Code (DTC) P1457: Evaporative Emission (EVAP) control system leak
detected (EVAP control canister system).
Fr4t6l
fF14s7
Possible Causs
. Fuel fill cap
. Vacuum Connections
. Fuel Tank
. EVAP Control Canister Vent Shut Valve
. EVAP Control Canister Vent Shut Valve Circuit
. EVAP Purge Control Solenoid Valve
. EVAP Purge Control Solenoid Valve Circuit
. EVAP Bypass Solenoid Valve
. EVAP Bypass Solenoid Valve Circuit
. Fuel Tank Pressure Sensor
. Fuel Tank Pressure Sensor Circuit
. EVAP Control Canister
. Throttle Body
Troublsshooting Flowchart
VACUUMPUMP/GAUGE,0 - 30 in.HgA973X - 041 -
xxxxx
I
EVAPCONTROL
.4, cANrsrER
re ./ VALVE
{S----r*::n
\(cont'd)
- The MIL ha3 been rePofted
on.- DTC P1456 or P1457 is stored.
Check the EVAP control canbtol
vent shut valve:1. Disconnect the vacuum hose
Irom the EVAP three waY
valve and connect a vacuurnpump to the hose.
2. Remove the EVAP control
canister vent shut valve Irofi
the canrster.3. Turn the ignition switch ON (lli
4. Apply vacuum to the hose.
Chock for . shon in the wire(VSv linel:Disconnect the 2P connector {rom
the EVAP control canister vent
Does the valve hold vacuum?
Repair short in the wir€ betwcen
the EVAP control canister vent
shut v.lve and tho ECM/PCM
tA29|.
Does the valve hold vacuum?
Check the EVAP control canister
vent shui valve:1. Turn the ignition switch OFF.
2. Connect ECM/PCM connectorterminal A29 to body ground
with a iumPer wire.
3. Turn the ignition switch ON (ll).
4. Applyvacuum to the hose
Reohce the EVAP control canis-
ter vent shttt valve.
Does the valve hold vacuum?
ECM/PCM CONNECTOR A {32P)
37I9t01t't2t3t5t6ItItt9202a2a
25aA
ILT GRN/W{T) I JUMPER WIRE
Wire side of femll terminals
(To page 11-284i(To page 11 284)
11-283