1996 HONDA CIVIC fuel gauge

Fuel Supply System
Fuel Lines (cont'dl
.99 - 00 models:
NOTE: Check all hose clamps and retighten if necessary.
: Do not disconnect the hose from the pipe.
ONBOARD REFUELING VAPORBECOVERY IORVRIVENT SHUT VALVE
B
FUELGAUGElt N.rn l1.a kgt.m,r0 lbt ftl
ftr, n'fo'PRESSUREREGULATOR
Clamp in the middle
Clamp in the middle
11-226

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

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

Emission Control System
Evaporative Emission {EVAP) Controls (cont'dl
\J
tF1456-l
tP14sz-l
EVAPCONTROLCANISTERVENTSHUTVALVE
O.RINGReplace.
EVAPCONTROLCANISTER
ECM/PCM CONNECTOR A I32PI
(To page 11'289)
'99 - 00 modols except Dl6Y5 engine with M/T:
The scan tool indicates Diagnostic Trouble Code (DTC) P1456: Evaporative Emission (EVAP) control system leak
detected (fuel tank svstem).
The scan tool indicates Diagnostic Trouble Code (DTC) P1457: Evaporative Emission (EVAP) control system leak
detected (EVAP control canister system).
Possible Cause
. Fuel fill cap
. Vacuum Connections
. FuelTank
. EVAP Control Canister Vent Shut Valve
. EVAP Control Canister Vent Shut Valve Circuit
. EVAP Purge Control Solenoid Valve
o EVAP Purge Control Solenoid Valve Circuit
. EVAP Bypass Solenoid Valve
0 -30 in,Hg
. EVAP Bypass Solenoid Valve Circuit
. Fuel Tank Pressure Sensor
. Fuel Tank Pressure Sensor Circuir
. EVAP Control Canister
. ORVR vent shut valve
. ORVR vapor recirculation valve
. Throttle Body
Troubleshooting Flowchart
VACUUMPUMP/GAUGE,A973X - oal -
xxxxx
T-t
t\
The MIL has been reported on.DTC P1456 o. P1457 is stored.
Check the EVAP cont.ol canistervent shul valve:1. Disconnect the vacuum hosefrom the EVAP three wayvalve and connect a vacuumpump to the hose.2. Remove the EVAP controlcanister vent shut valve fromtne canrster.3. Turn the ignition switch ON (ll).
4. Apply vacuum to the hose.Check for a short in the wiro(VSV linel:Disconnect the 2P connector fromthe EVAP control canister ventDoes the vaive hold vacuum?
RoDair 3hort in the wire botwe€nthe EVAP control canilter ventshut valve and the ECM/PCM{A4t.
Does the valve hold vacuum?Check the EVAP cont.ol canisterv€nl shut valve:1. Turn the ignition switch OFF.2. Connect ECM/PCM connectorterminal A4 to body groundwith a jumper wire.3. Turn the ignition switch ON (ll).
4. Apply vacuum to the hose.
Reolace the EVAP control canis-ter veni shut valve.
Does the valve hold vacuum?
Wire side of female terminals
11-288
lTo page 11-289)

IECM/PCM CONNECTOR
I
EVAP TWO WAYVALVE
Wire side oftemaleterminals
FUELTANK
(cont'd)
11-291
tn
VACUUMPUMP/GAUGE,0 - 30 in Hs
A973X - 041 -
xxxxx
(From page l1 290)
Check the EVAP two way valve:
See EVAP two way valve test (see
page 11-295).
Roplace the EVAP two way valve
Check the EVAP bypa$ solenoid
1. Remove the fuel tank (see
page 11-242J.2. LiIt up the fuel tank with a
transmission iack, and connect
the fuel tank pressure sensor
sub harness 6P connector to
the access panel side connec_
tor,3. Disconnect the vacuum hosefrom the EVAP two way valveand connect a vacuum PumPto the hose,4. Turn the ignition switch ON (ll)
5. Apply vacuum to the hose.
(To page 11 292)
(From page 11-290)
Check for an open in the wire
{PCS lin6):1. Turn the ignition switch OFF
2. Reconnect the 2P connector to
the EVAP purge control sole-
3. Turn the ignition switch ON {ll).4. Measu re voltage betweenEClr/PCM connector terminals
A6 and 82.
Ropair open in the wire betweenthe EVAP purge Gontrol solenoidvrlve and th6 ECM/PCM lA6lls there battery voltage?
Substitute a known-good ECM/
PCM rnd re{61. lf symptom/indi'
cation goes away, rePlace the
oiiginal ECM/PCM.

Emission Control System
Evaporative Emission (EVAPI Controls (cont'd)
Evaporative Emission (EVAPI Two Way Valve Testing
l'96 DIGYS engine lcoupel,'97 Dl6Y7 engine (coupe: KL
model, sedan: KL (LX) modoll,'97 Dl6Y8 engine {coup€:
alt models, sedan: KL model, '98-all modelsll:
1. Remove the fuel fill cap.
2. Remove the vapor line from the EVAP two way
valve. and connect it to a T-fitting from a vacuum
gauge and a vacuum pump as shown.
VACUUM/PRESSURE
IJ
f96 D16Y5 engine,'96 D16Y7 engine,'96 D16Y8 ongine
(sedanl,'97 D16Y5 engine,'97 Dl6Y7 engine {coupe: KA,
KC models, sedan: KA, KC, KL {DX} models, hatchback:
all modsls),'97 D16Y8 engine {sedan: KA, KC models}l:
1. Remove the fuel fill cap,
2. Remove the vapor line from the EVAP two way
valve on the fuel tank, and connect it to a T-fitting
from a vacuum gauge and a vacuum pump as
snown.
VACUUM/PRESSURE GAUGE,0 - 4 in.Hg07JAZ - 0010008VACUUMPUMP/GAUGE.0 -30 in.HgA973X-041 -XXXXX
Apply vacuum slowly and continuously while watch-
ing the gauge. The vacuum should stabilize momen-
tarily at 0.8 - 2.1 kPa (6 - 16 mmHg, 0.2 - 0.6 in.Hg).
lf the vacuum stabilizes (valve opens) below
0.8 kPa {6 mmHg, 0.2 in.Hg) or above 2.1 kPa
(16 mmHg, 0.6 in.Hg), install a new valve and retest.
Move the vacuum pump hose from the vacuum fit-
ting to the pressure fitting, and move the vacuum
gauge hose from the vacuum side to the pressure
side as shown.
Slowlv pressurize the vapor line while watching the
gauge. The pressure should be stabilize momentari
ly above 1.0 kPa (8 mmHg. 0.3 in.Hg).
. lf the pressure momentarily stabilizes (valve
opens) above '1.0 kPa (8 mmHg, 0.3 in.Hg), the
valve is OK.
. lf the pressure stabilizes below 1.0 kPa (8 mmHg,
0.3 in.Hg), install a new valve and retest.
Apply vacuum slowly and continuously while
watching the gauge. The vacuum should stabilize
momentarily at 0.7 - 2.0 kPa (5 - 15 mmHg, 0.2 - 0.6
in.Hg ).
lf the vacuum stabilizes (valve opens) below
0.7 kPa (5 mmHg,0.2 in.Hg) or above 2.0 kPa
(15 mmHg, 0.6 in.Hg), install a new valve and retest.
Move the vacuum pump hose from the vacuum fit-
'l'
4.
5.
ting to the pressure fitting, and move the
gauge hose from the vacuum side to the
side as shown.
PRESSURESIDE
Slowly pressurize the vapor line while watching the
gauge. The pressure should stabilize at 1.3 - 4.7 kPa
(0 - 35 mmHg, 0.4 - 1.4 in.Hg).
. It the pressure momentarily stabilizes (valve
opens) at 1.3 - 4.7 kPa (10 - 35 mmHg, 0.4 - 1.4
in. Hg), the valve is OK.
. lf the pressure stabilizes below 1.3 kPa (10 mmHg,
0.4 in.Hg) or above 4.7 kPa (35 mmHg. 1.4 in.Hg),
install a new valve and retest.
vacuum
pressure
GAUGE0- 4 in.Hg
T-FITTINGT-FITTING
11-294
\,

\
Evaporative Emission (EvAPl Two Way Valve T6ting
'99 - 00 modols:
'L Remove the fuel tank (see page 11-242).
2. Remove the vapor line {rom the EVAP two way
valve (located above the EVAP control canister), and
connect it to a T-fitting from vacuum gauge and
vacuum pumo as snown,
VACUUM/PRESSUREGAUGE0 - il in.Hg07JAZ - 001(x)08
ry(L
"*'"""_,";f1
T.FITTING
Apply vacuum slowly and continuously while watch-
ing the gauge.
The vacuum should stabilize momentarily at 0.8 -
2.1 kPa {6 - 16 mmHg, 0.2 - 0.6 in.Hg).
lf the vacuum stabilizes (valve opens) below
0.8 kPa (6 mmHg, 0.2 in.Hg) or above 2.1 kPa
(16 mmHg, 0.6 in.Hg), install a nsw valve and retest.
Move the vacuum pump hose from the vacuum fit-
ting to the pressure fitting, and move the vacuum
gauge hose from the vacuum side to the pressure
side as shown.
GAUGE,0 - 30 in.Hg4973X - (Xl -
xxxxx
J.
5. Slowly pressurize the vapor lin€ while watching the
gauge.
The pressure should be stabilize momentarily
above 1.0 kPa (8 mmHg, 0.3 in.Hg).
. lf the pressure momentarily stabilizes (valve
opens) above 1.0 kPa (8 mmHg, 0.3 in.Hg), the
valve is OK.
. ll the pressure stabilizes below 1.0 kPa (8 mmH9,
0,3 in,Hg), install a new valve and retsst.
(cont'd)
11-295