1997 HONDA CIVIC 11-230

!
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

Special Tools
a\-Special Tools
R€f. No. I Tool NumberDsscriptionOty I Pagr Reference
O
@/n
@
@
@
A973X_041 _ XXXXX
07JAZ - 0010008
07PAZ - 0010100
07sAz - 001000A
07406 - 0040001
07406 - 0040304
Vacuum Pump/Gauge, 0 - 30 in.H9
Vacuum/Pressure Gauge, 0 - 4 in.Hg
SCS Service Connector
Backprobe Set
Fuel Pressure Gauge
Fuel Pressure Adapter,6 x 15 mm
I
I
1
2
1
I
11-251,256, 257 ,273,27 4, 283,284,
286, 288, 289, 291,
294,296,297
11-294,295
11-81
11-83
1't-230, 231, 234
11-230
ta
1n\Y
11-2

Probable Cause List lFor th€ DTC Chart, see page 11-971*: '99 - 00 models
Probable GausePageSystem
11 1-107Engine Control Module (ECM)/Powertrain Control Module (l'uM)
PGM-Fl main relay
l^^iti^n cwetam
211-230,231
3't't-237
Section 23
51'1-172,183Crankshaft Position/fop Dead Center/Cylinder Fosltlon sensor clrculr' Lr\F selrsor
circuit
Intake Air Temperature (lAT) sensor circuit
ldle Air Control (lAC) Valve
ldle speed adjustment
Throttle bodY
Throftle cable
Manifold Absolute Pressure (MAP) sensor
Throftle Position (TP) sensor
Barometric pressure (BARO) senso'
Mf g"a, po"ition signal (see page 11-216) or clutch switch signal
Brake switch signal
Air Cleaner
lntake air pipe
Three Way Catalytic Converter (TWC)
Evaporative emission (EVAP) control
Contaminated fuel
ORVR vent shut valvs
't1-124
71 1-194
I11-220 - 223
11-241
'1011-244
1111-115
1211-132
13't1-178
14Section 14. 11-218
1511-210
16't1-244
1811-252
1911-261
20
21*11-296
(cont'd)
11-85

PGM-FI System
Random Misfire
lFoioo l*u o, [FTioo l*' *' and
The scan tool indicates Diagnostic Trouble Code (DTC)
P0300*5 or P1300*3 *1 and some of P0301 - P0304:Random misfire.Description
Misfire detection is accomplished by monitoring the crankshaft speed with the crankshaft speed fluctuation (CKF) sensorwhich is attached to the crankshaft.
lf misfiring strong enough to damage the catalyst is detected. the MIL will blink during the time of its occurrence, and DTCP0300*5 or P1300*3'*' and some of DTCs P0301 through P0304 will be stored. Then, after misfire has ceased, the MIL willcome on.
lf misfiring that increases emissions is detected during two consecutive driving cycles, the MIL will come on, and DTCP0300*5 or P1300*3 *a and some of DTCS P0301 through P0304 will be stored.NOTE: lf some of the DTCS listed below are stored at the same time as a misfire DTC. troubleshoot those DTCS first, thenrecheck for the misfire DTC.
P0106*4. P0107. P0108, P1128*3 *5, Pl129*3 *5; MAP sensorP0131. P0132: HO2S
P0171, P0112i Fuel metering
P0401, P 1491, P1498: EGR svstem*1P0505: ldle Control SystemP1253: VTEC System*,P1361, P1362: TDC sensorP1381, Pl382: CYP sensorP1508: IAC valve
Possible Cause. Fuel pump insufficient fuel pressure, amount of flow. Fuel line clogging, blockage, leakage. Fuel filter clogging. Fuel pressure regulator stuck open. EGR system malfunction*1. Distributormalfunction. lgnition coil wire open. leakage *l: D16Y5 engine. lgnition control module malfunction *2: D16Y5, D16Y8, Bt6A2 engine. MAP sensor range/performance, poor response*r *3: '97 models. Valves carbon deposit *4;'96 models. Compression low *5: '98 - 00 models. IAC valve malfunctionr.. VTEC system malfunction*,. Fuel does not meet Owner's Manual spec., lackoffuel. HO2S. HO2S circuit
Troubleshooting
By test-driving, determine the conditions during which misfire occurs, Depending on these conditions, test in the orderdescribed in the table below.
Possible
- --^ ---
rage
causeEGR*1
system
Crankshaft
position (CKP)
sensor
Fuel
pressure
Distributor and
lgnition wirestcMClearance
tAc
ValveMAP
sensor
section 611-230,
231section 23section 23section 611-19411
Only low rpm and
loado@@oo
Only accelerating@o@@
Only high rpm and
toaooo@
Not specificoo@
NOTE: lf misfire doesn't recur, some possible causes are fuel that doesn't meet owne/s manualspec, lack of fuel, carbon deposits on spark plug, etc.
1 1-1 66
I
P0304

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

Fuel Supply System
Fuel Injectors
Replacement
@ Do not smoke when working on the tuel systgm, Keep gp6n flames away from your work area
'f. Relieve the fuel pressure (see pages 11-230,231J.
2. Disconnect the connectors from thefuel injectors (D16Y7 engine: Remove the air cleaner).
3. Disconnect the vacuum hoses from thefuel pressure regulator. Placeashoptowel overthefuel return hose, then dis-connect it from the fuel pressure regulator. Disconnect the vacuum hoses and 2P connector from the EVAp purgecontrol solenoid valve.
4. Remove the retainer nuts on the fuel rail.
5. Disconnect the fuel rail.
6. Removethefuel injectors from the intake manifold.
D16Y5, D16Y8 engine:
NOTE: lllustration shows D16Y8 engine.
D16Y5 engine is similar.
12 N.m11.2 kgl.m,8.7 rbt.ft)
12 N.m11.2 lgl.m,8.7 rbt.ftl
.q
wE4
Y
Ve
ffi}Yg
E
O.RINGReplace.
CUSHIONRINGReplace.
O.RINGReplace.
cusl{toNRINGReplace.
SEALRINGReplace.
ffi
E
EV
R
w
t
YEVAPPURGE CONTNOLSOLENOID VALVE
FUEL
11-232

Fuel Supply System
Fuel Pressure Regulator
Te3ting
@ Do not smoke during the tast. Keep open
flamcs away from your work arsa.
1. Attach the special tool(s) to the service port on the
fuel filter (see pages 1 1-230, 231).
Pressure should bo:
except 81642 engine
260 - 310 kPa |'2.7 - 3.2 kgllcrn2,38 - /t6 psil
816A2 engine:
27O - 320 kPa 12.8 - 3.3 kgf/cm,, 40 - 47 psi)
{with the tuel pressure regulator vacuum hose
disconnested and pinched)
Reconnect the vacuum hose to the fuel pressure
regulator.
Check that the fuel pressure rises when the vacuum
hose from the fuel pressure regulator is disconnected
again.
lf the fuel pressure did not rise, replace the fuel
pressure regutalor.
CLAMP
REGULATOR
11-234
Reolacement
@@ Do not smoke while working on luel sys-
tem. Keep open flame away from your work area,
1. Place a shop towel under the fuel pressure regulator,
then relieve fuel pressure (see pages 11-230,231l..
2. Disconnect the vacuum hose and fuel return hose.
3. Remove the two 6 mm retainer bolts and the fuel
pressure regurator.
Apply clean engine oil to a new O-ring. and carefully
install it into its proper position.
Install the fuel pressure regulator in the reverse
order of removal.

I
FuelFilter
Replacement
r@. Do not smoke whilc working on fuel system. Keep
open flame away from your work arsa.
. While replacing the tuel filter, be catelul to koep a
sale distance betwoen battery torminals and any
tools.
The fuel filter should be replaced whenever the fuel
pressure drops below the specified value [260 - 310 kPa
12.7 - 3.2 ksl/cm',38 - 46 psi), |270 - 320 kPa (2.8 - 3 3
kgf/cm,, 40 - 47 psi))* with the fuel pressure regulator
vacuum hose disconnected and pinchedl after making
sure that the fuel pump and the fuel pressure regulator
are OK. *: 81642 engine
1. Place a shop towel under and around the fuelfilter.
2. Relieve fuel pressure (see pages 11-230,231]-
Remove the 12 mm banjo bolt and the fuel feed
pipe from the fuel filter, while supporting it with the
another wrench, as shown.
Remove the fuel filter ciamp and fuel filter'
lnstall the new fuel filter in the reverse order
removal, and note these items:
a When assembling, use new washers as shown
. Clean the flared joint of high pressure hoses
thoroughly before reconnecting them.
I
,96 MODELS:
(3.4 kgl.m,25 rbf.ftl
,97 AND LATER MODELS:
12 mmBANJOBOLT33 N.m
12 mmBANJOBOLT33 N.mt3.4 kgf m,25 lbf.fr)
\i(o-r
)
11-235