Fuel pressure HONDA CIVIC 1996 6.G Repair Manual

Emission Control System
Evaporative Emission (EVAP) Controls (cont'dl
!
FUEL TANKPRESSURE SENSOR3P CONNECTOR {C7921
PTANK
{LT GRN)
sG2{GRN/BLK)
Wire side of f€mal€ terminals
{From page 11-275)
Check to. ! short in the wiroIPTANK linol:Measure voltage between thefirel tank pressure sensor 3P con-nector No. 3 terminal and No. 2terminal,
ls there approx.5 V?
Check fo. a Short in the wireIPTANK IinoI:1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con,nector D 116P).3. Check for continuity betweenthe fuel tank pressure sensor3P connector No.3 terminalsand body ground.
Repair thort in thc wire betweantho fuel iank pre$uro 3€naor andECM/FCM tDl5t.
ls there continuity?
Substitute ! known-good ECM/PCM and recheck. lf .ymptom/indication go6s awry, repleco th6origin.l ECM/PCM.
PTANK{LT GRNI
-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)

Emission Control System
Evaporative Emission (EVAPI Controls {cont,dlJ
FUEL TANKPRESSURE SENSORSU8-HABNESS6P CONNECTOR 1C574 tC568)rt
PTANK
{LT GRN}
PTANK
ILT GRN}
Wire side of female terminals
(From page 11-277)
Check for a short in the wire{PTANK line):At the access panel side, measure voltage between the fueltank pressure sensor sub-harness6P connector No. 2 terminal andNo. 6 terminal.
ls there approx. 5 V?
Chock lor a Short in the wi.e(PTANK line):1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector A (32P).
3. Check for continuity betweenthe fuel tank pressure sensorsub-harness 6P connector No.2 terminals and body ground.
Repair short in the wi.e betwsenthe luel tank pressure sensor andECM/PCM {A291.
Subsiitute a known-good ECM/PCM and rechock. lf symptom/indication goes away, replac€ theoriginal ECM/PCM.
11-278

\
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)

\
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