1999 HONDA CIVIC Fuel pressur

Connector ldentification and Wire Harness Routing
Rear Heatod Oxygen Sensor Sub-harness
Connector or
Terminal
Number of
CavhiesLocationConnects toNotes
c7a1
c782
Under middle of dash
Under middle of dash
Main wire harness (C432)
Secondary heated oxygen sensor(Secondarv HO2S)
Fuel Tank Pressure Sensor Sub-harness
Connector or
Terminal
Number of
CavitiesLocationCono€cts toNotes
c791
c192
c793
6Middle of floor
Left side of fuel tank
Left side of fuel tank
Floor wire harness (C568: Coupe/
Hatchback, C574; Sedan)
Fuel tank pressure sensor
EVAP two way valve
FUEL TANK PRESSURE SENSOR
23-60

Gauge Assembly
Bulb Locations (With Tachometer)
GAUGE LIGHT II.' WI
SEAT BELTREMINDER LIGHT I1.4 WI
LOW FUELLIGHT 13 W)
RIGHT TURN SIGNALINDICATOR LIGHT I1.4 WI
A/T GEARGAUGE LIGHTS 13 W)
CI{ARGING SYSTEM LIGHT (1.,1W)
GAUGE I-IGHT {1,4 WI
LOW ENGINE OIL PRESSUREINDICATOR LIGHT (1,' W}
HIGH EEAMINDICATOR LIGHT(1.4 W)
GAUGE LIGHT l3.il Wl
MALFUNCTIONINDICATORLAMP {MIL}BULE (1.{ Wl
WASHER I.'C VELINDICATOR LIGHT{1.4 Wl (Canada)
LEFT TURN SIGNALINDICATOR LIGHT {1.4 WI
sRsTOB (1.4 Wl
{On the printed circuit board)INDICATOR (1.12 x 6l(On the printed
circuit board)
ABS |ND|CATOR (1.. Wl{On the printed circuit board)CRUISE or SHIFT-UP INDICATOR 11.12 11.{On the orinted circuit board)
23-136

Contents
How to Use This Manual ICircuit Schematics (see Circuit Index)Fuse/Relaylnformation 6Ground-to-Componentslndex 6-6ComponentLocationPhotooraohs 201Conriector Views 202
Circuit Index
Accessory power socket 155Air conditionerAir delivery'96198 models 61'99-'00 models 61-2Blower controls'96198 models 60'99100 models 60-1Compressor controls 62Fans 63Anti-lock brake system (ABS) 44A/T gear position indicatorCVT 89All except CVT 89-1Automatic transmission controlsAll '96-'98 models except CVT and GX 39All '99100 models except CVT 39-8All GX models 39-8'96-'98 CVT 39-4'99100 cw 39-12Back-up lightsCoupe and Sedan 110Hatchback l'10-1Brake lightsAll Coupes and'96-'98 Sedans 110-15'99-'00 Sedans 110-16Hatchback 110-17Brake system indicator light'96198 models 7'1'99100 models 71-1Ceiling light 114-3Charging system 22Condenser fan 63Console lights 114Cruise control 34Dash lights 114Daytime running lights 110- 13Engine coolant temperature gauge 81-1Fog lights 110-10Front parking lights 110-2Fuel gauge 81-1Fuse/relay boxUnder-dash 6Under-hood 6-4Underhood ABS 6-3Gauges 81Ground distribution 14Ground-to-Componentslndex 6-6Hazard warning lightsAll except '99100 Sedans 110-6'99100 Sedans 110-8Headlights 110-12Headlight switch 100Heater - See Air ConditionerHorn'96197 models 40'98 model 40-1'99100 models 40-2lgnition key reminder 73lgnition systemAll '96198 models except Dl685 20All '99100 models except D16Y5 with Mn 2O-2All D1685 engines 20-2'99-'00 D 16Y5 with M/T 20
lndicators 80Integrated control unit 70lnterlock systemAll except'96J98 CVT 138'96198CVT 138-1License plate lightsAll Coupes and '96-'98 Sedans I l0-3'99100 Sedans 1 10-4Hatchback 110-5Low fuel indicator light 74Moonrool'96197 models |22'98-'00 models 122-1Odometer 81Oil pressure indicator light 80-3Power distributionBattery to ignition switch, fuses, and relaysFuses to relays and components 10-2Power door locksAll models without keyless entry 130'96-'98 models with keyless entry 130-2'99100 models with keyless entry 130-12Power mirrorsWithout detogger 141With defogger '141-2
Power windows 120Programmed fuel injection system (PGNr-Fl)All '96-98 models except D1685 23All '99-'00 models except D16Y5with M/T and D1685 24All D1685 engines 25'99100 D16Y5 with M/T 23Radiator fan 63Rear window defogger'96-,98 models 64'99100 models 64-1Seat belt reminder 73Security system'96.'98 USA HX, LX, EX 133'96-'98 Canada EX, Si 133'99TOO USA HX, LX, EX, DX.V Si 133-4'99100 Canada EX, Si 133-4All CX and DX models 133-8Speedometer 81Starting systemA./T (All except Dl685) 21A"/r (D16Bs) 21-1Manualtransmission 21-2Slereo sound system 150Supplemental rastraint system (SRS) 47Tachometer 81TailliqhtsAllboupes and'96-'98 Sedans 110-3'99100 Sedans 1 10-4Hatchback 110-5Trunk light 114-3Turn signal lightsAll except'99100 Sedans 110-6'99-'00 Sedans 1 10-8Vehicle speed sensor (VSS) 33Wiper/washerFront 91Rear 92
10

Ground-to-Components I ndex
f.,lONOTE: All ground wires are BLK unless otherwise noted.
GroundPageComponents or Circuit Grounded
Battery (BLKYEL)
Steering pump bracket
t+-rg ITransmission housing
l
G101
(-1)
G101
(-2)
14-2
and
14-3
ano
14-1
Powertrain or engine control module (PG1 and pG2 are BLK: LG1 and LG2 are
BRN/BLK), EGR control solenoid valve (CW, EGR valve and lift sensor (Dt6yS enginewith M,/T), Engine coolant temperature switch, pGM-Fl main relay, power steeringpressure switch (USA), Primary HO2S (D16Y5 engine with l\/,/T), Vehicle speed sensor,VTEC pressure switch (D16Y5/D16Y8 engines), CKF sensor (BRN/BLK), Transmission
control module (CYf) (Pc1 is BLK: LG1 is BRN/BLK)
Shielding betvveen the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor. Primary and secondary heated oxygen sensors.
Knock sensor (CWDl6YB engine), Mainshaft speed sensor (AiT except CVT),
I Countershaft speed sensor (A/T except CVf)
Shielding between the TCM and these components (CVT) (all have BRN/BLK wires):
Drive pulley speed sensor, Driven pulley speed sensor, Secondary gear shaft
speed sensor
Powertrain or engine control module (PG1 and pG2 are BLK; LG1 and LGz are
BRN/BLK), EGR control solenoid valve (D16Y5 engine), EGR valve (Dt685), Engine
coolant temperature switch, Fuel pressure regulator shut-off solenoid valve (D1685),
PGM-FI main relay, Power steering pressure switch (USA), Vehicle speed sensor, VTECpressure switch (All except D16Y7 engine), CKF sensor (A

except 81642) (BRN/BLK)
Shielding between the PCM or ECM and these components (all have BRN/BLK wires):
CKF sensor, TDC/CKP/CYP sensor, Primary and secondary heated oxygen sensors,
Knock sensor (All except D16Y7 engine), i/ainshaft speed sensor (Arf except CW),
Countershaft speed sensor (A,/T except CVf), Drive pulley speed sensor (CW), Drivenpulley speed sensor (CVT), Secondary gear shaft speed sensor (CVf)
I Badiator fan motor, Right front parking/turn signat tight, Right headtight
G20214-4I Cruise control actuator, Left front parking/turn signal lights, Left headlight, Rear window
I washer motor, Windshield washer motor, Washer fluid level switch (,99-'00 Canada)
G401| +-o
and
14-7
Accessory power socket, Brake fluid level switch, Clutch interlock switch (M/T), Clutchswitch (lillT with cruise/D16Y5 engine with MfD, Combination wiper switch (Z wires),
Cruise control main switch, Cruise control unit, Dash lights brightness controller, Data
link connector, Daytime running lights control unit (Canada), Gauge assembly, Horn('96-'97 models), Integrated control unit, Interlock control unit (ArI), Keyless door lock
control unit ('99-'00 models with keyless), Moonroof close and open relays, Moonroof
switch, Park pin switch (A/r), Power window relay, Rear window defogger relay, Rear
window defogger switch ('96-'98 models), Steering lock, Stereo radio tuner (,96-,98
USA: LX, EX, and HX), Turn signal/hazard relay, Windshield wiper motor.....plus
everything grounded through G402
6-6

Ground Distribution
- Gl01 ('98 Dl685;All '99-'00 models except D16YS with M/T)
NOTE: Wires shown without color codes are black.
01685/_ D16Y5/ -.016Y8engrnes
.__-;,#'-_,--', engrne ;
, wEc: PRESSURE '
, swtTcH :I Page24-4 iI PHOTO 150: r -'l
:t | :
:l | :,L-J.
FUELPRESSUREREGULATOR ENGINESHUT.OFF COOLANTSOLENOID TEMPERATUREVALVE SWTTCHPage 25-1 Page 63PHOIO 143 PHOTA 33r-1F-.|
llll
lltlL-J L-J
POWERTRAIN olENGINE CONTROLMODULE (PCM or ECM)Page 24-3 ot 25-3PHOTO 86
----:y4
tl
tl
PGi,|.FIMAINRELAYPage 24ol 25
vlEw 18
tl
tl
3Y'I'I
excaptD1685
VEHICLESPEEDSENSOR(vss)Page 336FN/ELKERll/EIKcl01PHOTO 21PHOTO 142(o1685)vtEw 28
ct16Cferml-nals8n 4)
FltaFt( vttw 39t- .''iiti ' " D1685/D16Y5 engrnes ---'
t2
. ENGINE : :
i 933'?il-; i 5"T,Yf,*' 33i,"o, i
i lgfft" i I S.ir1".l^ soL€NorD :' Pase 63 : : ;;;;; - pase 24.i :' PHOTO 63 | | VtEWlO pHOIa124 ;, r-1 | , F-.t r-.r
:l | ;:l | ! | :;t | :,t | | | ;
j,f
ii T.__.,|,,,,,.
j
--
----- --l i otoas I Dr6y5 :
:------.1.--------.
14-2
o-----J

From B
WHT/BED
WHT/REO
WHT/FED
W}ITIRED
2
c401
vlEw 73
WIIT/BED
LJ*
;.;.il,
m
:il
"u"T.l,
m
*
a
From A onfacing page.
v
I
*"rr"a^ |
,L-:l'il
mm-'
1:-a PHO|O147
I See Ground8LX I oistribtnbn,
|
*'"J'.
v'a-
FUELINJECTORRELAYPHOTO 135
r S€s Groundarr< Dietribution.
FUEL PRESSUREREGULATORSHUT.OFFSOLENOIDVALVE
: c4o'lc150
vtEW 72
r-
IT
;.;..{
'm'
m'ill"'"-"'
,t,iJ,-,
i{
it.;:;t"'-
INJECTORCONTROLMODULE
See G.oundDislribution,pag€ 14-3.
Y
!
BFN/BLKI-J
I
I Distribr;tion,I pags r{-6.
ti: clot
y'o,JPHOIO 86
G101
-"----.< c.t 16- -J (Terminals'l-7)""'7lw;8"'"
Ground GrouftGround Ground
fu*gr PorYgrfl[J2) (rNJ3] 0NJ4]
;:[
2s-1
!-'
BFN/BLK

PGM-FI (D1685) (cont'd)
EGRvdvo Fuer ia ( tEGR In pres$uro \valvs s€mor nd*6nc6 lP i.snsor h.tsl lank tenF, Icont ol inDut volt|ce s8fi8of inDul inbut ssnsof ifix, I: control inDln voltac€ s€{tlor input inout sonsol ingJl ;I G.€GF} GGf,q N@a fiPg' .(PFoJ fiFO) ,L------- ------J
j
c2887
c150PHOTO 112
C'ro1PHO|O sl
c575
vtEw 7i
(FUELTA}IKTEMPEB.ATURESENSOR
H1Y
FUEL TANKPRESSURESENSOnPHOTO 116
THROTTLEPOSrT|0NCIP)SENSOR
EXHAUSTGAS RECIR.CULATION(EGR) VALVEand LIFTSENSORPHOfO 36
"""r":x
o
GRI{/BLK
4
GNN/BLK
GNN/gLK
c575
c401PHOfO 57vtEw 40
2
GRN/BL(
cls0
a
POWERTBAINCONTROLMOOULE(PCM)PHOfO 86
I
I
IJ
n"*r"a^[
'rcai/BLX llcre Ar--?
lsJiH,
I ground
I
25-6

How the Gircuit Works
All Except GX
Do not smoke while working on the fuel system.
Keep open flame away trom the work area. Drain
fuel only into an approved container.
A thermistor is mounted in the fuel tank unit. When
the thermistor is cool, its resistance is very high.
When the thermistor's temperature increases, its
resistance decreases. Fuel in the fuel tank transters
heat away lrom the thermistor fast enough to keep it
cool so the thermistor's resistance stays high and
lhe low fuel indicator light does not come on. When
the fuel level drops below the thermistor, the
thermistor's temoerature increases. Without the fuel
to cool it, the thermistor's resislance decreases,
allowing current to llow through the low fuel
indicator light and the thermistor to ground, and the
low fuel indicator light comes on.
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
GX
The PCM turns on the low fuel indicator light when
the fuel level is low. The PCM will also blink the
indicator light when a problem is detected by the
fuel tank pressure sensor or the fuel tank
temperature sensor.
Refer to the Service Manual GX Supplement
(Section 11 , Fuel and Emissions) for specific tests
or troubleshooting procedures.
74-1