1996 HONDA CIVIC Signal

Fuel Supply System
- Repair op€n or short in thewir€ betlveen the PGM-FI mainrelay and the No. 31 STARTERSIGNAL 17.5 A) fuse.- RoDlace the No. 31 STARTERSIGNAL {7,5 Al tuse in theunder-dash luse/rolay box.
ls there battery voltage?
Check tor an open in the wire(FLR linel:1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector A (32P).
3. Check for continuity betweenthe PGM-FI main relay 7P con-nector terminal No. 1 and ECM/PCM connector terminal A16.
Repair open in the wir6 botweenthe ECM/PCM (A161 and rhePGM-FI main relay.
Check for an open in the wires{lGPl, lGP2 line3):1. Reconnect the ECM/PCM con-nector A {32P).2. Reconnect the PGM-Fl mainrelay connector.3. Turn the ignition switch ON (ll).
4. Measure voltage betweenECN4/PCM connector terminals81 and 820, and betweenBg and 820.
- Repair open in the wire bet-ween th. ECM/PCM (81, Bg)snd the PGM-F main rolay.- Roplace th€ PGM-FI main relav.
Chock tor an open in th6 ECM/PCM:1. Turn the ignition switch OFF.2. Measure vo ltage betweenECM/PCM connector terminalsA16 and 82 when the ignitionswitch is first turned ON lll) for
Sub3titute . known-good ECM/PCM and rochock. lf prescribedvohege is now available, replacethe original ECM/PCM.
ls there 1.0 V or less?
Chock the PGM-Fl m.in r6lay{see p.ge 11-2371.
PGM-FI Main Relay (cont'd)
_._(9x . qq -gqerll _
PGM.FI MAIN FELAY 7P CONNECTOR {C4€}FLR
ECM/PCM CONNECTORS
A (32P1
Wire side ot female terminals
Wire side of fem6le terminals
ECM/PCM CONNECTOR B {25PIIGP2 {YEL/BLKI
IGRN/YEL}
IGP2(YEL/BLKI
Wire side of female terminals
11-240
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Emission Control System
Exhaust Gas Recirculation (EGR) System (D16yS engine)
Doscription
The EGR system is designed to reduce oxides of nitrogen emissions (NOx) by recirculating exhaust gas through the EGRvalve and the intake manifold into the combustion chambers. lt is composed of the EGR valve. EGR vacuum conrrot vatve.EGR control solenoid valve. ECM and various sensors.The EcM contains memories for ideal EGR valve lifts for varying operating conditions, The EGR valve lift sensor detectsthe amount of EGR valve lift and sends the information to the ECM. The ECM then compares it with the ideat EGR valve liftwhich is determined by signals sent from the other sensors. lf there is any difference between the two. the EcM cuts cur-rent to the EGR control solenoid valve to reduce vacuum applied to the EGR valve.
EGR CONTROLCVT: SOLENoID vALvE
EGN VALVE LIFT SENSOR
BLK
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11-254

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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:
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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)

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'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
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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
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ll
(To page '11-278)
(cont'd)

Emission Gontrol System
Evaporative Emission (EVAP) Controls (cont'dl
ORVR Vent Shut Valve Test
Float Test
1. Make sure the fuel tank is less than half full.
2. Remove the fuel fill cap to relieve the fuel tank pres-
sure, then reinstall the cap.
3. Remove the fuel hose joint protector. Disconnect
the ORVR vapor recirculation hose, and connect a
vacuum pump to the vapor recirculation hose.
ORVR VAPOERECIRCULATION
VACUUM PUMP/GAUGE,0 - 30 in.H9A973X - 041 -
xxxxx
Plug the hose port.
Apply vacuum to the ORVR vapor recirculation
nose.
. lf the vacuum holds, replace the ORVR vent shut
valve {see page 11-297).
. lf the vacuum does not hold, the float is OK.
4.
11-296
Vatve Tcst
1. Make sure the fueltank is lessthan halffull.
2. Remove the fuel fill cap.
3. Remove the fuel hose joint protector. Disconnect the
ORVR signal hose.
ORVRSIGNALHOSE
Disconnect the vacuum hose from the EVAP control
canister. and then plug the port with a plug.
VACUUMPUMP/GAUGE,0 - 30 in,HgA973X-041-XXXXX
CONTROLCANISTERVENT SHUTVALVE
Disconnect the vacuum hose from the EVAP control
canister vent shut valve, and connect a vacuum pump
to the vacuum hose,
Pump the vacuum pump 80 times.. lf the vacuum holds, go to step 7,. lf thevacuum does not hold, goto step9.

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7. Connect a second vacuum pump to the OBVR signal
nose.
VACUUM PUMP/GAUGE.0 - 30 in.HgA973X - 041 -
xxxxx
Apply vacuum (1 pump) to the ORVR signal hose,
then check the vacuum on the pump in step 6.
. lf the vacuum holds, replace the ORVR vent shut
valve.
. lf the vacuum is released, the ORVR vent shut
valve is OK.
Disconnect the ORVR quick disconnect from the EVAP
canister, then plug the port on the canister.
Reapply vacuum (80 pumps).
. lf the vacuum holds, reDlace the ORVR vent shut
valve,
. lf the vacuum does not hold, inspect the EVAP can-
ister vent shut valve O-ring. lf the O-ring is OK,
replace the EVAP canister and repeat step 4.
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11-297
ORVR Vent Shut Valve Replacement
1. Remove the fuel tank (see page 1 1-242).
2. Remove the ORVR vent shut valve from the fuel tank.
3. lnstall oarts in the reverse order of removal.

Description
Electronic Control System (cont'd)
Shift Control
The PCM instantaneously determines which gear should be selected by various signals sent from sensors, and actuatesthe shift control solenoid valves A and B to control shifting. Also. a Grade Logic Control System has been adopted to con-trol shifting in E position while the vehicle is ascending or descending a slope, or reducing speed.
PoshionGearShift Control Solenoid
Vslve A
Shift Control Solenoid
Valve B
8,tr
1stOFFON
2ndONON
3rdONOFF
E4thOFFOFF
tr2ndONON
E-ReverseONOFF
*See page 14-31 for reverse inhibitor control description.
Lock-up Control
From sensor input signals, the PCM determines whether to turn the lock-up ON or OFF, and activates lock-up controlsolenoid valve A and/or B accordingly. The combination of driving signals to lock-up control solenoid valves A and B andthe linear solenoid pressure is shown in the table below.
Lock-up ConditionsLock-up Control
Solenoid Valvo A
Lock-up Control
Solenoid Valve B
Linoar Solonoid
Prggguro
Lock-up OFFOFFOFFHigh
Lock-up, HalfONDuty operation
OFF * ONLow
Lock-up, FullONONHigh
LOCK-Up
during decelerationONDuty operation
OFF - ON
a
14-14

GRADE LOGIC CONTROL SYSTEM
How it works:
The pCM compares actual driving conditions with driving conditions memorized in the PCM, based on the input from the
vehicle speed sensor, the throttle position sensor, the barometoric pressure sensor, the engine coolant temperature sensor,
the brake switch signal, and the shift lever position signal, to control shifting while a vehicle is ascending or descending a
slope, or reducing speed.
SIGNALS OETECTED
O.iving Resi3lence
Judgemenl ot Conirolling Arca
. Ascending mod€
lFuzzy loqicl. Gradual Ascending mode' Ste€p Ascending mode. Oescending mode. Gr.du.l Descending mode. Steep D6cending mode
14-15