vacuum lines HONDA CIVIC 1996 6.G Workshop Manual

!
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

,'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

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
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

\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)

Emission Gontrol System
Evaporative Emission (EVAPI Controls (cont'dl
(From page 11-271)
I
ECM/PCM CONNECTOR D I32P}
PGl IBLKI
Check the EVAP purge controlsolenoid valvei1. Reconnect the EVAP purge
control solenoid valve 2P con-nector.2. Connect ECM/PCM connectorterminals A15 and 410 with a
Check for an open or short in thewire (PCS line):Measure voltage between ECM/PCM connector terminal A15 andbody gro!nd.
Does the solenoid valve clickwhen the jumper is connected?
Che'ck for a short in the wir6 {PCSline):1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector A (32P).
3. Disconnect the EVAP purgecontrol solenoid valve 2P connector.4. Check lor continuity betweenbody ground and ECM/PCMconnector terminal A15.
Repai. short in the wir6s betwoonthe EVAP purge control solanoidvalve and ECM/rcM lA15l.
R€pair op€n in the wir$ betwo€ntho EVAP purge control solenoidvalve and ECM/rcM lA15l.
Check the vacuum lin€3:Check the vacuum lines ol EVAPsystem for misrouting, leakage,breakage and clogging.
Are the vacuum lines OK?
PCS {REO/YEL)
t389t0'tt
12l3'I'tt5t5'11IE1920232a
?5212A2930
PCS {RED/YEL)
23a67E9t0It
12t3'ta't5l617ta1920222321
2a2728A30
0) Pcs {REo/YELI
-272

\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)

\
Fue| Tank Pr€ssure sensor 196 Dr6Y8 engine (coupe},,97 D16Y7 angino (coupo: KL mode|' 3edan: KL (Lxl modg||',97
Dl6Y8 engine (coupe: all modeb, sedan: Ki model.'98'all modols) 39 - 0O Dl6Y5 ongins with M/Tl:
rFoG'l::;Jl"too|indicatesDiagnosticTroub|ecode(oTc)P0453;Ahighvo|tageprob|emintheFue|TankPressure
ECM/PCM CONNECTOR D Il6PI
PTANKILT GRNI
\
Wire side of tgmale torminals
FUEL TANKPRESSURE SENSOR3P CONNECTOR (C792)
vcc2(YEL/BLU}
sG2(GRN/BLKI
Wire sid€ of female terminals
I
sG2IGRN/BLKI
PTANKIGBN/RED}
(cont'd)
11-279
The MIL has beon reponed on
DTC P0453 b stored.
Check the vacuum lines:
Check the vacuum lines oI the
fueltank pressure sensor for mis-
routing, leakage, breakage and
clogging.
Are the vacuum lines OK?
Problem verification:1. Do the ECM/PCM Reset Proce-
dure.2. Femove the fuel fill cap
3. Turn the ignition switch oN (ll).
4. Monitor the FTP Sensor volt-
age with the Honda PGM
Tester, or measure voltage
between bodY ground and
ECM/PCM connector termrnal
D15.
lntormittont t iluro, 3Ystem is OK
at this time. Check lot Poor con_
noctiona or loo3e wirat at C131
{loc.ted undor right 3id6 of d8hl,
CaOl llocatod rbov. under-dalh
fus6/relay boxl, C574 (C568lr
llocatod und6l accoss Pan6ll,C792 lfuel tank Preasulo aonlorl
end ECM/PCM.
ls there approx. 2 5 V?
Check for an oPen in the wire(SG2line):1. Turn the ignition switch OFF.
2. Reinstall the fuellill 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 terminals No. 1 and
No.2.
Ropair opon in the wira b€tw€sn
the fuel tank prasure sonlor and
ECM/PCM (Dl1).ls there aPProx. 5 V?
Check for an open in the wire(PTANK line):Measure voltage between the
fueltank Pressure sensor 3P con-
nector No. 3 terminal and No. 2
termrnal,
ls there approx. 5 V?
*: coupe
{To page 11-280)

\
'99 - 0O modols except Dl5Y5 engine with M/T:
rFo45'::n":"tooIindicatesDiagnosticTroub|ecode(DTc)P0453:Ahighvo|tageprob|emintheFUelTankPressure
Wire side of temale terminals
FUEL TANKPRESSUNE SENSOR
SUB.HARNESS6P CONNECTOR {C574 (C568)}}
vcc2{YEL/BLUI
sG2IGRN/BLK)
Wire side of female terminals
PTANK{LT GRNI
(cont'd)
11-281
ECM/PCM CONNECTOR A {32P)
PTANK {LT GRN)
The MIL has been reported on.
DTC P0453 is stored.
Check the vacuum lines:
Check the vacuum lines ot the
fuel tank pressure sensor for mis-
routing, leakage, breakage and
clogging.
Are the vacuum lines OK?
Problem verilication:1. Do the ECM/PCM Reset Proce-
du re,2. Remove the fuel fill caP
3. Turn the ignition switch ON (ll).
4. Monitor the FTP Sensor volt'
age with the Honda PGM
Tester, or measure voltage
between body ground and
ECM/PCM connector terminalA.29.
lntermittent failuro. svstem b OK
at this time. Check for Poor con_
noctions or loo3€ wire3 at C131
{located under tight side of dash),
C4Ol {located above underdash
fuse/relay boxl, C57{ (C5681'
llocaled unde. access Panell,C792 {fuel tank Pressure sensorl
aod ECM/PCM.
ls there approx.2.5 V?
Ch€ck for an open in the wira
{SG2line):1. Turn the ignition switch OFF.
2. Reinstall the fuel fill caP
3. Remove the access Panellrom the floor.
4. Disconnect the fuel tank Pres-sure sensor sub-harness 6P
5. Turn the ignition switch ON (ll)
6, At the access Panelside, mea-
sure voltage between the fuel
tank pressure sensor sub_har-
ness 6P connector termlnals
No.5 and No.6.
Repair open in the wire between
the fueliank Pres3ure 3ensor and
ECM/PCM {Cl8).ls there approx.5 V?
Check lor an oPen in the wire
{PTANK linel:At the access Panel side, mea
sure voltage between the fuel
tank pressure sensor suo_harness
6P connector No. 2 terminal and
No. 6 terminal.
ls there approx. 5 V?
(To page 11.282)