1997 HONDA CIVIC Fuel sending

Fuel Gauge
Gauge/Sending Unit Test
!@ Do not smoke while working on tho fuel
system. Keep open tlame away trom your wotk atea.
NOTE: Refer to page 23-133 for the fuel gauge system
circuit.
'1. Check the No. 25 (7.5 A) fuse in the under-dash fuse/
relay box before testing.
2. Remove the access panel from the floor.
ACCESS PANEL
Disconnect the 3P connector from the fuel gauge
sending unit.
Connect the voltmeter positive probe to the No. 2
terminal and the negative probe to the No. I termi-
nal, then turn the ignition switch ON (ll).
There should be between 5 and 8 V.
. lf the voltage is as specified, go to step 5.
. lf the voltage is not as specified. check for:- an open in the YEUBLK or BLK wire.- poor ground (G552).
Turn the ignition switch OFF.
Attach a jumper wire between the No. 1 and No. 2
terminals, then turn the ignition switch ON (ll).
)\
23-142
1.Check that the pointer of the fuel gauge starts mov-
ing toward the "F" mark.
CAUTION: Turn the ignition switch OFF before thepoinier reaches "F" on ihe gauge dial. Failure to do
so may damage the fuel gauge.
NOTE: The fuel gauge is a bobbin (cross-coil) type,
hence the fuel level is continuously indicated even
when the ignition switch is OFF, and the pointer
moves more slowly than that of a bimetaltype.
. lf the pointer of the fuel gauge does not move at
all, replace the gauge.
. lf the gauge is OK. inspect the fuel gauge send-
ing unit.
Remove the fuel gauge sending unit as shown.
Japan-produced
USA, Canada-produced

J
9. lMeasure the resistance between the No 1 and No. 2
terminals at E {EMPTY), 112 \HALF FULL) and F
(FULL) by moving the lloat.
USA, Canada-produced {Ceramic board type):
Too ot lhe workbench (Bottom of the fuel tank)
ll the resistance readings are beyond the range. replace
the fuel gauge sending unit
Float PositionE1t2F
Resistance (0)105 - 10829.5 - 35.53.5-5
Jaoan-Ploduced (Wire-wound typel:
Float PositionE1/2F
Resistance (O)105 - 11025.5 - 39.5
Low Fuel Indicator Light Test
NOTE: For the low fuel indicator circuit diagram, refer to
the gauge assembly circuit diagram (see page 23'2311.
1. Check the No. 25 (7 5 A) luse in the driver's under
dash fuse/relay box before testing
2. Park the vehicle on level ground.
3.
4.
Drain the luel into an approved container. Reinstall
the fueltank drain bolt with a new washer.
Add less than 4L (1 1 U.S Gal, 0.9 lmp Gal) of fuel,
and turn the ignition switch ON (ll). The low fuel
indicator light should come on within four minutes'
. lf the light comes on within four minutes, go to
step 8.
. lf the light does not come on within four min-
utes, go to step 5.
Remove the access panel lrom the Iloor'
Turn the ignition switch OFF, then disconnect the
fuel tank sending unit 3P connector.
Connect the fuel tank sending unit 3P terminals No'
1 and No. 3 with a jumPer wire
. lf the light comes on, replace the fuel gauge
sending unit (see Page 23 1421
. lf the light does not come on, check for:
- An open in the GRN/YEL wire between the
fuel gauge sending unit and the fuel gauge
- A blown bulb.- A poor ground (G552)
6.
1.
female terminals
8. Add 4L {1.1 U.S. Gal, 0 9 lmp Gal) of fuel The light
should go off within four minutes.
23-143

Gauges (cont'd)
- How the Gircuit Works
When the ignition switch is in ON (ll) or START (lll),
battery voltage is supplied through fuse 25 to the
gauges in the gauge assembly.
Speedometer and Odometer
The odometer and soeedometer drive circuits
receive pulses from the vehicle speed sensor
(VSS). The pulse rate increases as the car
accelerates. The frequency and duration of these
input pulses are measured and displayed by the
speedometer, odometer and tripmeter.
Tachometer
The tachometer drive circuit receives pulses from
the ignition control module (lCM) in the distributor
assembly or the ECM/PCM. The solid-state
lachometer then displays these pulses as engine
speed. For each 200 pulses per minute from the
ignition control modul€ (lCM) or the ECM/PCM, the
tachometer displays 100 RPM.
Engine Coolant Temperature Gauge
The engine coolant temperature gauge has two
intersecting coils wound around a permanent
magnet rotor. Voltage applied to the coils, through
fuse 25, generates a magnetic lield. The magnetic
field, controlled by the coolant temperature sending
unit, causes the rotor to rotate and the gauge
needle to move. As the resistance in the sending
unit varies, current through the gauge coils
changes. The gauge needle moves toward the coil
with the strongest magnetic field.
The 6ngine coolant temperature sending unit's
resistance varies from about 137 ohms at low
engine temperature to between 3H6 ohms at high
temperature (radiator fan running).
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
81-2
(
Fuel Gauge (All except cX)
The fuel gauge has two intersecting coils wound
around a permanent magnet rotor. Voltage applied
to the coils, through tuse 25, generates a magnetic
field. The magnetic field, controlled by the fuel
gauge sending unit, causes the rotor to rotate and
the gauge needle to move. As the resislance in the
sending unit varies, current through the gauge coils
changes. The gauge needle moves toward the coil
with the strongest magnetic field.
The fuel gauge sending unit's resistance varies
from about 2-5 ohms at full, to about 110 ohms at
empty. When you turn the ignition switch off, the
gauge remains at the last reading until you turn the
ignition switch to ON (ll) or START (lll) again,
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting procedures.
Fuel Gauge (GX)
The fuel gauge has two intersecting coils wound
around a permanent magnet rotor. Voltage applied
to the coils, through fuse 25, generates a magnetic
field. The magnetic field, controlled by the PCM,
causes the rotor to rotate and the gauge needle to
move. The PCM calculates the gas quantity in the
fuel tank by using the fuel pressure value detected
by the tuel tank pressure sensor and the fuel
temperature value detected by the fuel tank
temperalure sensor, and outputs the signal to the
gauge assembly. The gauge needle moves toward
the coil with the strongest magnetic field.
When you turn the ignition switch off , the gauge
remains at the last reading until you turn the ignition
switch to ON (ll) or START (lll) again. When the
PCM detects a malfunction with the fuel pressure or
temperature, or detects a gas leak, the PCM
reduces the fuel meter to 0.
Refer to the Service Manual GX Supplement
(Section 11 , Fuel and Emissions) for specific tests
or troubleshooting procedures.
a
a

Connector Views (conrd)
71. Gauge Assembly
- Left side of dash
Connector A (A/T only)
- Green- On dashboard wire harness
1 YEL (lgnition input)
2 RED/BLK (Headlight
switch ON input)
3 RED(Dash light brightnesscontroller input)
4 BLU (L or 2indicator control)
6 D16Y7/D16Y8:BRN (Not used)
8 BLK (G401)
Connector B
- Blue- On dashboard wire harness
2 BLK (G401)
3 BLU/BLK (Trunk openindicator light control)
4 GRN/YEL (Hazard
warning switch input)
5 GRN/RED(Brake system indicatorlight control)
6 RED/BLU (Seat beltindicator light control)
7 '96-'97 model: BLU,ryEL(not used)
8 Except GX: GRN/YELGX: 8LU/GRN(Low fuel indicator lightcontrol)
9 D16Y7/D16Y8: YEL01685/016Y5:GRN/BLK(D4 or D indicatorcontrol)
10 GRN (03 or Sindicator control)
11 RED(N indicator control)
12 WHT(F indicator control)
13 BLI(BLU(P indicator control)
14 LT GBN(Park/neutral output)
10 Except GX: YEUBLKcX: ORN/BLU(Fuel gauge controlinput)
11 BLUAVHT(Vehicle speed sensor(VSS) input)
12 YEUGRN (Engine
coolant temperaturesending unit input)
14
15 BLI(IVHT(lgnition input)
16 WHT/BLU(Charging systemindicator light control)
202-30
Connector C
- Blue- On dashboard wire harness
1 *: YEL (lgnition input)
2 *: PNK (Washer lluidlevel input)
3 YEUBED(Low oil pressureindicator light control)
4 YEL (lgnition input)
5 GRN/ORN (Malfunctionindicator light control)
6 RED/GRN
{Lights on Hl input)
7 GBN/RED (Hazardwarning switch input)
*= '99-'00: All except CVT
Connector D
- Orange- On dashboard wire harness
BLU/RED (ABS
indicator light control)
8 BLU(Engine speed input)
10
12 FED(Dash light brightnesscontroller input)
13 RED/BLK (Headlightswitch ON input)
I
2
3
4
5
BLK (G401)
YEL (lgnition input)

Connector ldentification and Wire Harness Routing
Connector
or
Terminal
Number ot
Cavities/
Golor
LocationConnects toNotes
Engine Wire Harness (Dl6Y5, D16Y8 engines): '96-98 models and '99;00 D16Y5 dM/T
c101
c102
c 103
c104
Q104
c105
c106
c107
cl 08
cl09
cl10
c1l1
cl'12
c113
c114
c'115
c116
c'117
c 118
c119
c120
c121
c122
c123
c123
c124
Q124
c125
c 126
c127
c128
c129
c130
c131
cl32
c 134
c135
c136
c137
c138
c139
c'140
c141
c142
c143
c144
c'|44
c145
c146
c147
1O-GRY
3.GRY
1-CLR
4-GRN
3-N/A
2-BLK
2-BLK
2-BLK
2-BLK
3-GRY
3-GRY
3-GRY
2.BLK
2.GRY
2-BLK
14-BLU
14-GRY
3.GRY
2-BLK
2-GRY
1O-GRY
1.BLK
2.GRY
4-GRY
8-GRY
2-GRY
2.GRY
4-GRY
2.BLK
2.BLK
2-GRY
1.BLK
2O.BRN
22.GRN
32.GRY
25.GRY
31-BLU
16.GRY
14-GRY
8.GRY
2-GFIY
2.GRY
1-GRY
2-GRY
2-BLK
2-GRY
2.BLK
3-GRY
6-GRY
2.BLK
8-GRY
2-BLK
Left side of engine compartment
Left side of engine
Middle of engineI att .i.la ^f an^i^6
Left side ot engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
[,liddle of engine
Middle ot engine
Middle ot engine
Middle of engine
Middle of engine
Middle of engine
l\,liddle of engine
Right side of engine compartment
Right side of engine compartment
Middle ot engine
Middle of engine
Middle of engine
Middle of engine
l\,liddle of engine
Nliddle of engine
Middle ot engine
Middle of engine
Middle ot engine
Middle of engine
Middle of engine
Nliddle of engine
Right side of engine
Under right side of dash
Behind right kick panel
Below right front footrest
Below right front footrest
Below right front footrest
Below right front tootrest
Left side ot engine compartment
Left side of engine compartment
Middle of engine
liliddle ot engine
Middle of engine
Nriddle ol engine
Right side of engine compartment
Middle ol engine
Right side of engine compartment
Middle of engine
N,liddle of engine
Right side of engine compartment
Right side of engine compartment
Bight side of engine compartment
Main wire harness
CKF sensor
Engine oil pressure switch
Alternator
Alternator
No. 1 fuel injector
No. 2 fuel injector
No. 3 fuel injector
No.4 fuel injector
IAC valve
TP sensor
MAP sensor
IAT sensor
Power steering pressure switch
EVAP purge control sol€noid valve
Junction connector
Junction connector
Vehicle speed sensor (VSS)
Countershatt speed sensor
Engine coolant temperature switch
Distributor
Engine coolant temp. sending unit
ECT sensor
Primary HO2S (sensor '1)
Primary HO2S (sensor '1)
Back-up light switch
Lock-up control solenoid valves
Secondary HO2S (sensor 2)
lvlainshafl speed sensor
Lanear solenoid
Shift control solenoid valves
Starter solenoid
Junction connector
Main wire harness
ECM/PCM connector A
PCM connector B
ECM/PCNI connector C
ECM/PCl\,,| connector D
Main wire harness
Maln wire harness
Knock sensor (KS)
IAC valve
VTEC solenoid valve
VTEC pressure switch
EVAP control canister vent shut valv€
EGR control solenoid valve
Secondary gear shatt speed sensor
EGR valve
EGR valve
Drive pulley speed sensor
CVT transmission solenoid
Driven pulley speed sensor
USA
Canada
AlT
USA
'2( tr\
'3
-1 (M/r)
t\4/T'2 (Anl'1
'2 (An)'2 (Nr)'2 (AtT)
'2 (Atr)
-1 (An)-2( fi|
M/T
.1 (Arr).1 (A,T)"1 (A/r)-1 (M/r).1 (CVT),1 (cw)'1 (CVT)
203-2

Connector ldentification and Wire Harness Routing
Connector
or
Terminal
Number of
Cavities/
Color
LocationConnects toNotes
Engine wire Harness (Dl6Y5, Dl6Y8 engines): '99-'00 models except D16y5 w/M/T
c 101
c102
c103
cl04
c104
c105
c106
c107
c108
c109
c110
c111
cl12
c1 13
c115
c117
c118
c119
c120
c120
c12'l
cl22
c123
c124
c124
c125
c126
c127
c128
c129
c130
c'131
c133
ct34
c 135
c137
c138
c139
c 140
c142
c143
c144
c'|45
c147
1O-GRY
3.GRY
1-CLR
4-GRN
3-N/A
2.BLK
2.BLK
2-BLK
2.BLK
3-GRY
3-GRY
3.GRY
2-BLK
2.GRY
2-BLK
14-BLU
14-GRY
3-GRY
2-BLK
2-GRY
1O-GRY
8.GRY,1-BLK
2.GRY
4.GRY
4.GRY
2.GRY
2.GRY
4.GRY
2.BLK
2-BLK
2-GRY
1-BLK
2O-BRN
22-GRN
25-GRY
31-BLU
16-GRY
2-GRY
2.GRY
1-GRY
2-GRY
2-GRY
2-BLK
3.GRY
2.BLK
8-GRY
2.BLK
Left side of engine compartment
Left side of engine
Middle of engine
Left side of engine
Left side of engine
Middle ot engine
Middle of engine
N,liddle of engine
l\4iddle of engine
Middle of engine
Niliddle of engine
N,,liddle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Rjght side of engine compartment
Right side of engine compartment
Middle of engine
Mlddle of engine
l\4iddle of engine
Middle of engine
Middle of engine
[iliddle of engine
lvliddle of engine
Middle of engine
Middle of engine
l\4iddle of engine
Middle ol engine
Middle of engine
N,liddle of engine
Right side of engine
Under right side of dash
Behind right kick panel
Below right front tootrest
Below right front footrest
Below right lront footrest
[iliddle of engine
l\,liddle of engine
Middle of engine
Middle of engine
L4iddle of engine
Right side of engine compartment
Middle of engine
Right side of engine compartment
Right side of engine compartment
Right side ot engine compartment
Main wire harness
CKF sensor
Engine oil pressure switch
Alternator
Alternator
No. 1 fuel injector
No. 2luel injector
No. 3 fuel injector
No.4 fuel injeclor
IAC valve
TP sensor
MAP sensor
IAT sensor
Power steering pressure switch
EVAP purge control solenoid valve
Junction connector
Junction connector
Vehicle speed sensor (VSS)
Countershaft speed sensor
Engine coolant temperature switch
Distributor
Distributor
Engine coolant temp. sending unit
ECT sensor
Primary HO2S (sensor 1)
Primary HO2S (sensor 1)
Back-up light switch
Lock-up control solenoid valves
Secondary HO2S (sensor 2)
Mainshait speed sensor
Linear solenoid
Shift control solenoid valves
Starter solenoid
Junction Connector
Main wire harness
ECN4/PCM connector B
ECM/PCM connector C
PCM connector D
Knock sensor (KS)
IAC valve
VTEC solenoid valve
VTEC pressure switch
EGR control solenoid valve
Secondary gear shaft speed sensor
EGR valve
Drive pulley speed sensor
CVT transmission solenoid
Driven pulley speed sensor
USA
Canada
ATT
USA
'2 (An\
'1
-1 (cw)
Mft'2 lNr)'1
'2 (Afil'2 (An)'2 (Anl
Atf
t\4/T
-1 (CVr)'1 (CVT).1 (CW)-1 (CVT)'1 (CVT).1 (cw
203-4

Connector ldentification and Wire Harness Routing
Connector
or
Terminal
Number of
Cavities/
Color
LocationConnects toNotes
Engine Wire Harness (Dl6Y7): '96 model
c101
c102
c103
cl04
c104
c 105
c106
c107
c108
c109
c110
c111
c112
c11 3
c114
c115
c116
c117
c118
c119
c120
c121
c122
c123
c124
cl24
c125
c126
c127
cl28
c129
c130
c131
cl32nl2?
c134al eR
1O.GRY
3-GRY
4.GRN
3-N/A
2.BLK
2-BLK
2-BLK
2-BLK
3.GRY
3-GRY
3.GRY
2-BLK
2.GRY
2-BLK
14-BLU
14-GRY
3.GRY
2.BLK
2-GRY
1O-GRY
1 -BLK
2-GRY
4.GRY
2.GRY
2-GRY
4-GRY
2.BLK
2-BLK
2-GRY
1-BLK
2O-BRN
22-GRN
32.GRY
25-GRY
31-BLU
16.GRY
Left side of engine compartment
Left side of engine
Middle of engine
Left side of engine
Lefl side of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Right side of engine compartment
Right side of engine compartment
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Right side of engine
Under right side of dash
Behind right kick panel
Below right front footrest
Below right front footrest
Below right front footrest
Below right front footrest
Main wire harness
CKF sensor
Engine oil pressure switch
Alternator
Altemator
No. 1 fuel injector
No. 2 fuel injector
No. 3 fuel injector
No. 4 fuel injector
IAC valve
TP sensor
MAP sensor
IAT sensor
Power steering pressure switch
EVAP purge control solenoid valve
Junction connector
Junction connector
Vehicle speed sensor (VSS)
Countershaft speed sensor
Engine coolant temperature switch
Distributor
Engine coolant temperaturesending unit
ECT sensor
Primary HO2S (sensor 1)
Back-up light switch
Lock-up control solenoid valves
Secondary HO2S (sensor 2)
Mainshaft speed sensor
Linear solenoid
Shift control solenoid valves
Starter solenoid
Junction Connector
Main wire harness
ECM/PCM connector A
PCM connector B
ECM/PCM connector C
ECM/PCM connector D
USA
Canada
A/T
USA
Atf
Aff
M/T
Arl
AtT
A/T
Afi
T101
T102
Left side of engine compartment
Right side of engine compartment
Alternator
Under-hood fuse/relay box
G101Right side of englneEngine ground, via engine wirenarness
203-6

Connector ldentification and Wire Harness Routino
Conneclor
or
Terminal
Number of
Cavities/
Color
LocationConnects toNotes
Engine Wire Harness (Dl6Y7 engine): '99100 models
c101
Q102
c103
c104
c104
c105
UIUO
c107
c108
c109
c110
c111
c112
c113
c114
c11s
c116
c117
c118
c119
c120
c121
c122
c123
c124
cl24
c126
c\27
cl28
cl29
c 130
c131
c'133
c134
v tJc
1O-GRY
3.GRY
1-CLR
4-GRN
3.N/A
2-BLK
2.BTK
2.BLK
2-BLK
3-GRY
3-GRY
3-GRY
2.BLK
2-GRY
2-BLK
14-BLU
14.GRY
3-GRY
2.BLK
2-GRY
8-GRY
1.BLK
2-GRY
4-GRY
2-GRY
2-GRY
4.GRY
2-BLK
2-BLK
2-GRY
1-BLK
2O.BRN
22-GRN
25-GRY
31 -BLU
16-GRY
Left side of engine compartment
Left side of engine
Middle of engine
Left side of engine
Left side of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle ol engine
Middle of engine
Middle of engine
Middle of engine
Right side of engine compartment
Right side of engine compartment
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Middle of engine
Right side of engine
Under right side of dash
Behind right kick panel
Below right front footrest
Below right front footrest
Below right front footrest
Main wire harness
CKF sensor
Engine oil pressure switch
Alternator
Altemator
No. 1 fuel injector
No. 2 fuel injector
No. 3 fuel injector
No. 4 fuel injector
IAC valve
TP sensor
MAP sensor
IAT sensor
Power steering pressure switch
EVAP purge control solenoid valve
Junction connector
Junction connector
Vehicle speed sensor (VSS)
Countershaft speed sensor
Engino coolant temperature switch
Distributor
Engine coolant temperature
sending unit
ECT sensor
Primary HO2S (sensor 1)
Back-up light switch
Lock-up control solenoid valves
Secondary H02S (sensor 2)
Mainshatt speed sensor
Linear solenoid
Shifi control solenoid valves
Starter solenoid
Junction connector
Main wire harness
ECM/PCM connector B
ECM/PCM connector C
PCM connector D
USA
Canada
USA
AIT
Mrl
Atf
AN
A/T
AlT
Afi
T101
r'l02
Left side of engine
Right side of engine compartment
Alternator
Under-hood fuse/relay box
G 101Right side of engineEngine ground, via engine wirenarness
203-10