1996 HONDA CIVIC Fuel tank lines

!
Fuel and Emrsslons
SoecialToofs .....,...."..,. 11-2
Component Locations
lndex ....................., ......... 11-3
Svstem Description
Vacuum Connections ................,,..,.. ......... 11-12
Electrical Connections ...............,.,.,... ....... 11-29
System Connectors ........,.,.,.......................... 1 1-51
Troubleshooting
Troubleshooting Procedures ................. .. 11-81
Engine Control Module/PowertrainControl Module TerminalAfiangement ....,.,..... 11-88
Diagnostic Trouble Code Chart .................,., 11.97
How to Read Flowcharts .,.......................... . 11-103
PGM-Fl System
System Description ...... 11-10,1
Troubleshooting Flowcharts
Engine Control Module/PowertrainContlol Module ........ 11-107
Manitold Absolute Pressure Sensor .....'. . ... 11-115
fntake Air Temperatuie Sensor ..... . . ., . 11'121
Engine Coolant Temperatuae Sensol ........., 11-128
Throttle Position Sensor ...................,........... 11-132
Primary Heated Orygen Sensor (Sensor 1l ... 11-139
Secondary Heated Oxygen Sensor(Sensor 21.................................................... 1 1-153
Heated Oxygen Sensor Heater ...................,. 11-157
Fuel Supply System ...... 11-164
Random Mislire ......., ..11-166
Misfire Detected in One Cylindsr ................. 11-167
Knock Sensor .,.,............ 11-170
CKP/TDC/CYP Sensor ................................... 11'172
Vehicle Speed Sensor ...........,......,...,.,........... 1t-176
Barometric Pressure Sensor ...............,......... I 1-178
Electrical Load Detector,.,,............................ 1 1-179
CKF Sensor .................... 11-183
ECM/PCM Internal Circuit ............................. I 1-188
A/T Signal {TMA/TMBI .................................. I 1-189
ldle Control System
System Doscriplion ............ 11-190
Troubleshooting Flowcharts
ldle Control System ...... 11-192
ldle Air Control Va1ve .................................... I 1-19i1
Starter Switch Signal .................................... 1 1'202
Air Conditioning Signal ................................. 11'201
Ahernator FR Signal .................................... . 1 1-208
BrakeSwitch Signal ..................................... f 1"210
Power Sleering Prossure Switch Signal ......11-212
A/T Gear Position Signal ............................... 11-216
Clutch Swiich Signal ................................-.... 11-214
ldte Speed Setting . .............11-220
Fuel Supply System
Fuel Lines .,...................,.,.,.,11-221
Fuef Tube/Ouick-Connect Fittings ..........,.,........ 11 -227
System Description ....'.... 11-230
Fuel Pressure .......,.,,........... 11-230
Fuef fniectors ......................11-232
Fu€f Pressure Regulator .....,.......................'...,. 11-231
Fuef Fifter ............................11-235
Fuel Pump .............'.......'.... 11-236
PGM-FI Main Relay .............11'237
Fuel Tank ................ ....,...'.'.' 11'211
Intake Air System
System Description ....-.-.....11-243
Air Cfeaner ...........,......."". .11-211
Throttle Cable .....................11-211
Throttfe Body ........ ..'... . . .,.11-211
Fuel Iniestion Air Control System ,.,.,....-........... 11-250
Emission Control System
System Description .-..........11-252
Taifpip€ Emission ...............11-252
Three Way Catafytic Convert€r ............,.,,.,.,.,.... 11 -252
Exhaust Gas Racirculaiion System ...,.,,,,.,.,.,.,,. 11'254
Positive Crankcas€ Ventilation System .... . . .. 11-266
Evaoorative Emission Controls ..................,,..,.,. 11 -267

Troubleshooting
Engine/P_o,wertrain Control Module Terminal Arrangement('99 - 00 Models except Dl6Y5 engine with M/Tl
ECM/PCM CONNECTOR A (32P)Wire side ot temale terminalsNOTE:Standard battery voltage is l2 V
ECM/PCM CONNECTOR A I32PI
Sign!l
3BLU2WSS (EVAP 8YPAsS SOLENOIDDrives EVAP bypass solenoid vatve,With gn'tion swnch ON (lll banery votlage
LT GRN/I/VIITVSV {EVAP CONTNOL CANISTERVENTSHUTVALVE]Drives EVAP controt ca n isrer v€nt shutWilh ignilion switch ON {tl): b€ttery vottage
8LU/GNNC8S (CRUISE CONTSOL SIGOown shift signal inpot lrom c.uise conrrolWhen crurss control is used:purses
68ED/YELPCS {EVAP PURGE CONTROLSOTENOIOVALVE)Drives EVAP purge conrrol sotenoid vatve.With engine running, engine cootant, betow r54.F (6a,C):
With engine.unning, €ngine coolant, abov€ 154.F(68'C): duty conlrolled
YELATPD {AT GEAR POSITIONSWITCH)ootects A/T gear posnion swilch s,gnar.In otherthan @ posilion: Apprcx. 5 V
8BLK,IflHTSO2SHTC (SECONDARY HEATED OXYGEN SENSOS HEATEFCONTFOL)
Drives sscondary h€ared oxygen senso.Wilh isn,rion swirch ON (ll):banery votraseWith lully warm6d dp€ngire runn'ng:dury controled
LT GRNATPNP (AT GEAF POSITIONSWITCH)oereds A/T 9€a r position switch signat.In Parr or neulrsl:0 VIn anyother position approx.5 v
t088NSCS (SERVICE CHECK SIGNAL)Oetects ssruice check connecror signal(the signalcausing a OTC indication)with rh€ t6rminal connected: 0 vWith the rerm ina I disconneded: abour 5 V of ban€ry
GNN/BIKD4IND (D4INDICATON]Drives Oa indicaio. lighr.With D4 indicator lightturned ON: O VWith D4 indicator lightturned OFF: battery vo ttageG8N/YETFTF (FUEL PUI\,4P SELAY)Orivos tuel pump relay,0V for two s€conds lfrer turnrng rgnilior swtcn ON(ll), then batt€ry voltage11BTI(REDACC (Al/C CTUTCH SELAY)Drives A./C clutch reray.With compressor ON:O VWilh comp.ssor OFF; battery vottage18GFN/OFNMI! (A,IAIFUNCTION INDICA.TOF LIGHT)With MlLturned ON:0 VWith l\,llL tornod OFF|batrery votrsge198tuNEP (ENGINE SPEED PUTSEIOulputs6ngine speed pulse,Wilh engin6.unning: putses
20GFNFANC {SADIATOR FAN CONTnoL)Orives radiarortan relay.Wirh r.distor t6n running:OVWith radiatortan stopped: banery vottage21ELUA/ELK LINESends and r€ceives s.an lool signal.With ignition switch ON (ll):p!ts€s
22'lBLUATP L {AT GEAS POSITIONswtTcH)Oelocis A"/T gear posirion switch siSnat.In othfflhan E position: Apprcx. 5 V
23SHO25 (SECONOARY HEATEDOXYCEN SENSOR, SENSOF 2)Detects secondsry hoar€d oxygen sensorWith lhronle f! lly or'6ned from idte with fu ywarmod up engine: above 0.6 vWiih th.onl6 quickb, closd:below 0,4 V24STS ISTAFTEN SWITCH SIGDebcrs staner switch signat.Wirh srarterswitch ON (tttJ: batteryvottogeWith sraftsr cwirch OFF:0 V26GFNPSPSW iPlS PNESSURESWITCII SIGNAL)Derecrs PSP switch signat.Atidle with steoring wheolin srraightahead position: O VAt idl6with steering wheetal fult lock: barery vo ttags27BLU/REOACS (AJC SWITCH SIGNALJOer*ts ,ay'C swirch signat.Wiih ty'C switch ON;0VWilh Ay'C switch OFF|aboor 5VWHT/REDSLU iINTERLOCK CONTROIUNIT)Drivos interloct control unit.With ignltion switch ON (ll)and brake pedaldepresed: batlory volrage29LT GRNPTANK (FUEL TANK PFESSUEESENSOR)Oer6ds lu€l tank pr€ssura sonsor signat.Wilh ig.rrrd swirch ON rttr and fuetti

cap ooen6d.
30GRN/FEOEr (ELOIWith parking lighlsrurned on ar idteiaboui 2.5- 3.S VWirh low beam he€dlig hts turnqd on ai idts: aboul 1.52.5 V32GRN/'WHTAKSW (BFAKE SWITCH)Detets brak€ swrtch signEt,With brake pedal r6l€ased:0 VWhh brake pedaldepres*d: battery voltEse'1:A./T (D16Y7, D16Y8 engine)*2: rvt/T13: CVT (D16Y5 engine)
11-92

,'o
L
*:The E indicator light and the Maltunction Indicator Lamp (MlL) may come on simultaneously.*1: D16Y5 engine (CVT)"5: '96 D16Y5 engine, D16Y7 engine, D16Y8 engine (sedan).'97 D16Y5 engine, Dl6Y7 engine (coupe: KA, KC models, sedan: KA.
KC, KL (DX) models, hatchback: all models), D16Yg engjne (sedan: KA, KC models)*6: '96 D16Y8 engine (coupe),'97 Dl6Y7 engine (coupe: KL model, sedan: KL (LX) model),'97 D'16Y8 engine (coupe: all models,
sedan: KL model),'98-all models,'99-all models,'00-all models*12: Except A,,/T (D16Y7, D16Y8 enginei*13: A"/T (D16Y7, D16Y8 engine)!l*14:'97 model*16:'98 model" 17: '99 - 00 models
(cont'd)
1 1-99
DTC{MlL indication}Detoction lt€mProbable C.usePage
P0441*5 (92)
Evaporative Emission ControlSystem InsufficientPurge Flow
EVAP Purge Control Solenoid VaiveOpen or short in EVAP Purge Control
Solenoid Valve circuitEVAP Control CanisterVacuum linesECM/PCM
11-271
P0451'11 (91)FuelTank Pressure Sonsor CircuitRange/Parformance
. FuelTank Pressure Sensor' ECM/PCM11 274
P0452{6(9r )
Fuel Tank Pressure Sensor CircuitLow Input
Short in FuelTank Pressure Sensor circuatFuel Tank Pres$ure SensorECM/PCM
11-275
P0453*6 {91)
Fuel Tank Pressure Sensor Circuit
High Input
ODen in Fuel Tank Pressure Sensor circuit
Fuel Tank Pressure Sensor
ECM/PCM
11-219
P0500*1, (17)Vehicle SpeedSensor CircuitMalfunction
V€hicle Speed SensorVehicle Speed Sensor circuit
ECM
11-176
P0501*'3 l17l
Vehicle SpeedSensor CircuitRange/Performance
V€hicle Sp€ed SensorVehicle Speed Sensor circuitPCM
r 1- 176
P0505 (14)ldle Control Systemlvl a lfu n ctio n
. IAC valve. Throttle Body11-192
P0700*r3and some ofP0715P0720P0730 (70)*
P0740P0753P0758
AutomaticTransaxle
Section 14
P0700*1and (70)*
P0725
Automatic TransaxleSection 14
(13)Barometric PressureCircuitRange/Performance Problem
. ECM/PCM (Baro sensor)1 1-178
P1107 (13)BarometricPressure CircuitLow Input
. ECM/?CM (Baro s€nsor)11-178
P1108 (13)BarometricPressure CircuitHigh Input
. ECM/PCM lBaro sensor)1 1-178
P1121*'. *16. *'? \71Throttle Position Lower ThanExpected
. I r sensor11-138
P1122'14.*16.*n 17lThrottle Position Higher ThanExpected
. TP sensor11-'138
15)Manifold Absolute PressureLower Than Expected
. MAP sensor1 1'123
P1129*1r.*16.*"(5)Manifold Absolute PressureHigher Than Expected
. MAP sensor't1-123

PGM-FI System
(From page 11-109)
Replace the sensor that causedthe light to go out.Does the N4lL go OFF?
Check fo. a short in the wi.os(VCC lines):':. Turn the ignition switch OFF.2. Disco n n ect the ECM/PCMconnector D (16P).
3. Check for continuity betweenbody ground and ECM/PCMconnector terminals D4 andD10 individually.
Ropair short to body groundin the wire betweon ECM/PCM {O4) and MAP s6n3or.Repair short to body groundin the wire between ECM/PCM lD10l, the TP sensor, theEGR valve lift sensor {D16Y5engine) and/or the Fuel tankpressure sensor {'96 Dl6Ygengine lcoupe),'97 D16Y7engine (coupe: KL model,sedan: KL (LXl model), '97
D16Y8 engine (coupe: allmodels, sedan: KL model. €8-allmodelsl.
ls there continuity?
Check tor rn open in the wires(lGP lines):1. Disconnect the fuel injectorsand IAC valve connectors,2. Turn the ignition switch ON (ll).3. Meas u re voltage betweenbody ground and ECM/PCMconnector terminals A11 and424 indivjdually.- Repair open in the wirels)between ECM/PCM (A11,A24land PGM-Fl main relay.- Check for poor connectionsor loose wiras at the PGM-FImain relay,- Test the PGM-FI mdin relavlsee pag6 11-237).
ls there battery vohage?
Check for an open in the wires(LG line3):1. Reconnect all sensor connectors.2. Reconnect the ECM/PCM con-nector D (16P).
3. Turn the ignition switch ON (ll).4. Measure vo ltage betweenbody ground and ECM/PCMconnector terminals Ag andA22 individually.
Repair open in the wirolglb€twe€n ECM/PCM {A9, A22} andG101 that had more than 1.0 V.
ls there less than 1.0 V?
Substitute 6 known-good ECM/PCM and r€check. lf symptom/indication 9o€s away, replacethe original ECM/PCM.
Engine Control Module/Powertrain Control Module (ECM/pCMl
('96 - 98 Models, '99 - 00 D16Y5 engine with M/Tl (cont,dl
ECM/PCM CONNECTOR D {16P}
Wire side of female terminals
ECM/PCM CONNECTOR A (32P}
Wire side of female terminals
11-110
LG1
VCCl {YEL/RED}
IGP 1{YEL/BLKI
2I11
1213l5t6Itt8t9202321
25272a2930
IGP 2(YEL/BLKIv) (l
{8RN/BLK)
I258tol1'12tt11t5l617t8t920232a
2A2330
LG2{8RN/8LK}

PGM-FI System
(From page'11-111)
Check loi an open in the wires(lGP linesl:1. Disconnect the lueliniector andIAC valve connectors.2. Turn the ignition switch ON (ll).
3, Measu re voltage betweenbody ground and ECM/PCMconnector terminals 81 andBg individually.
- Repair open in the wiro(3)between ECM/PCM lBl, B9land PGM-Fl main relay.- Check tor poor connectionsor loose wires al the PGM-FImain relav.- Test tho PGM-FI main rehy(3.e page 11-237).
ls there battery voltage?
Check tor an open in the wires(PG, LG lines):1. Reconnect the fuel iniectorand IAC valve connectors.2. Measure voltage betweenbody ground and ECM/PCMconnector terminals 82, 810,820 and 822 individually.
Repair open in the wirels)between ECM/PCM and G 101llocated ai the l6ft side of thointaks m.nifoldl thrt h.d morethan 1.0 V.
ls there lessthan 1.0 V?
Check for a short in the wires
{VCCI, VCC2 lin6s}:Measure voltage between bodyground and ECM/PCM connectorterminals C19 and C28 individually.Check toa a 3hort in s 3ensor:While measuring voltagebetween body ground and ECM/PC[/t connector terminals C19and C28 individually, disconnectthe 3P connector of each sensorone at time:. MAP sensor. TP sensor. EGR valve. Fueltank pressure sensor
ls there approx.5 V?
Reoair short in lhe wire betwe.enMAP 3ansor, TP sensor, EGRvalve, Fuel tank pres3ure 3ensorand ECM/PCM {Cl9, C28).
ls there approx. 5 V?
Substiiute a known-good ECM/PCM and racheck. ll symptom/indicetion goes eway, replaceth6 original ECM/PCM.Replace tho sansor that had.pprox. 5 V.
Engine Control Module/Powertrain
('99 - 00 Model except Dl6Y5 (M/Tl
Module (ECM/PCM)
(cont'd)
Control
engine)
ECM/PCM CONNECTOR B {25P)
LG1 (BRN/BLKI
Wire side of female terminals
ECM/PCM CONNECTOR C (31P)
female terminalsvcc2IYEL/BLUIvccl{YEL/RED)
Wire side of female terminals
11-112

Fuel Supply System
System Description
The fuel supply system consists of a fuel tank, in-tank
high pressure fuel pump, PGM-FI main relay, fuelfilter,
fuel pressure regulator, fuel injectors. and fuel delivery
and return lines. This system delivers pressure-regu-
lated fuel to the fuel injectors and cuts the fuel delivery
when the engine is not running.
Fuel Pressure l'96 Modelsl
Relieving
Before disconnecting fuel pipes or hoses, release pres-
sure from the system by loosening the 6 mm service
bolt on top of the fuel filter.
. Do not smoke whil6 working on the fuel system.
Kgsp opon flames or sparks away from youl work
area.
. Be sure to relieve fuel pressure while the ignition
switch is off.
1. Write down the frequencies for the radio's preset
buttons.
2. Disconnect the battery negative cable from the bat-
tery negative terminal.
3. Remove the fuelfill cap,
4. Use a box end wrench on the 6 mm service bolt at
the fuel filter while holding the special banjo bolt
with another wrench,
5. Place a rag or shop towel over the 6 mm service bolt.
6, Slowly loosen the 6 mm service bolt one complete
rurn.
. A fuel pressure gauge can be attached at the 6 mm
service bolt hole.
. Always reDlace the washer between the service
bolt and the special banjo bolt whenever the ser-
vice bolt is loosened.
. Replace all washers whenever the bolts are
removeo.
11-230
Inspoction
1. Relieve fuel pressure.
2. Remove the service bolt on the fuel filter while hold-
ing the banjo bolt with another wrench. Attach the
special tool.
FUELPRESSUREGAUGE07406 - 00ir0(x)1
Start the engine. Measure the fuel pressure with the
engine idling and the vacuum hose of the fuel pres-
sure regulator disconnected from the fuel pressure
regulator and pinched. lf the engine will not start,
turn the ignition switch ON (ll), wait for two sec-
onds, turn it off, then back on again and read the
fuel pressure.
Pr€3sure should bo:
260 - 310 kPa (2.7 - 3.2 kgt/cmr, 38 - 46 psi)
Reconnect vacuum hose to the fuel pressure regulator,
Pressure should bo:
200 - 25O kPa l2.O - 2.5 kgf/cm', 28 - 36 psil
lf the fuel pressure is not as specified, first check the
fuel pump {see page 11-2361. lf the fuel pump is OK,
check the following:
. lf the fuel pressure is higher than specified,
inspect for;- Pinched or clogged fuel return hose or line.- Faulty fuel pressure regulator (see page 11-234).. lf the fuel pressure is lower than specified, inspect
for:- Clogged fuelfilter.- Faulty fuel pressure regulator {see page 11-234).- Fuel line leakage.
REGULATOB

\J
Fuel Tank Pro3sure sensor 196 D16Y8 engine (coupe).'97 D15Y7 engine {coupe: KL model, sedan: KL (LX) modeu,'97
D16Y8 engine (coupe: all models, sedan: KL model, '98-all models) '99 - 00 D16Y5 engine with M/Tl:
\
PTANK
{LT GRNI
vcc2(YEL/BLU}
Wire side oI female terminals
FUEL TANKPRESSURE SENSOR3P CONNECTOR (C7921
sG2IGRN/8LK)
Foc2l::il":"toolindicatesDiagnosticTroublecode(DTc)P0452:A|owvo|tageprob|emintheFue|TankPressure
The fuel tank pressure sensor converts fuel tank absolute pressure into electrical signals and inputs the EcM/PCM.
OUTPUTVOLTAGEtvt4.5
-? kPa(-50 mmHg,-2 in.Hg)
ECM/PCM CONNECTOR O I16P)
Wire side of female terminals
+7 kPs150 mmHg,2 in.Hg)
PRESSURE
(cont'd)
11-275
- The MIL has been reported on- DTC P0452 is stored.
Check the vacuum lines:
Check the vacuum lines of the
fuel tank pressure sensor for mis-
routing, leakage, breakage and
cloggrng.
Are the vacuum lines OK?
Problem v€ritication:1. Do the ECM/PCM Reset Proce
dure.2. Remove the luel fill caP.
3. Turn the ignition switch ON lll)4. Monitor the FTP Sensor volt_
age with the Honda PGM
Tester, or measure voltage
between bodY ground and
ECM/PCM terminal Dl5.lntermittent tailuro, sYstem i5 OK
dt this timo. Chock for Poot con-
neciion3 or loose wir* at C131
llocatod under right side ot dashl,
C4O1 (located .bove under'da3htuso/ielay box), C574 1C568)*
{located under acc€ss Panell.C792 lfuel tank pressule sen3or)
and EcM/PCM.
ls there approx. 2.5 V?
Check tol an op€n in wite (VCC2
line):1. Turn the ignition switch OFF
2. Reinstallthe fuel fill caP.3. Disconnect the fuel tank Pres'sure sensor 3P connector-4. Turn the ignition switch ON (ll)
5, Measure voltage between the
fuel tank pressure sensor 3P
connector No. l terminal and
No. 2 terminal.
Repair open in the wite betweenthe fuel tank Pr€s3ure a€n3or andth6 EcM/PcM (D1ol.ls there approx. 5 V?
(To page 11'276)

\
'99 - 00 models excepi Dl6Y5 engine with M/T:
The scan tool indicates Diagnostic Trouble Code (DTC) P0452: A low voltage problem in the Fuel Tank Pressure
sensor.
The fuel tank pressure sensor converts fuel tank absolute pressure into electrical signals and inputs the ECM/PCM
OUTPUTVOLTAGE(vlt.5
0.5-7 kP.(-g) mmHg,-2 in.Hgl
+7 kP.
150 mmHg,2 in.Hgl
PRESSURE
I
Wire side of lemale terminals
FUEL TANKPRESSURE SENSORSUB.HARNESS6P CONNECTOR (C574 (C568)rl
vcc2(YEL/BLUIsG2{GRN/BLK}
Wire side o{ temale terminals
The MIL has been .eported on.
DTC P0452 is stored
Check the vacuum lines:
Check the vacuum lines of the
fuel tank pressure sensor lor mis-
routing, leakage, breakage and
cloggrng.
Are the vacuum hnes OK?
Problem veritication:1. Do the ECM/PCM Reset Proce-
du re,2. Bemove the fuel fill caP.
3. Turn the ignition switch ON {ll)
4. Monitorthe FTP Sensor voltage
with the Honda PGM Tester' or
measure voltage between body
groLrnd and ECM/PCM connec_
tor terminalA29.
lntermitlent tailure, 3Ystem b OK
at this time. Check for Poor con'
nections or loose wire3 at C131
{located under right side of dash},
C401 {located above under'dash
tuse/relay box), C574 (C568)*
llocdted under access Panel),C792 (tuel rank Prcssure sensorl
and ECM/PCM.
ls there approx.2 5 V?
Check for an open in wire {VCC2
line):1. Turn the ignition switch OFF.
2. Reinstall the ltrel fill caP
3, Remove the access Panel from
the floor.4. Disconnect the fuel tank Pres'sure sensor sub-harness 6P
5. Turn the ignition switch ON (ll).
6. At the access Panel side, mea_
sure voltage between the fuel
tank Pressure sensor sub-nar-
ness 6P connector No 5termi
nal and No. 6 termlnal.
Repair open in tho wire between
th6 fu€l tank Prossuro sen3oa and
the ECM/PCM lc28).ls there approx 5 V?
ECM/PCM CONNECTOR A (32P)
PTANK {LT BLUI
I
ll
(To page '11-278)
(cont'd)