coolant temperature HONDA CIVIC 2000 6.G Repair Manual

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

-.t POWERTRAIN
lcoNTRoL
Fuel I MODULE
\. . -,.^-- p{sssure
I llglllTP-. . sansor sensor .s€nsor i;ir*,o; sensor_rnpul input input input :I nFa (PF2) GcD i|An IrL------ --------Jc13 I' c14Y c26
FUELTEMPERATURESENSOR
Fromfacingpage.
v
!
_l
Fromnenpage.
vi
GFN/BLK lI
i
EG-f
flltur'ffi
,{J
ENGINECOOLANTTEMPERATURE(Ecr)SENSOR
INTAKEAIRTEMPERATURE(rAr)SENSOR
c't 15(ferminals &14)
vtEw 38
(cont'd)
25-7

Fans
- AllModels\,1 |
splicedtogetherinstead of inthe junctionconnector onDl6Y5 models
c211PHOTO 11
FANRELAYPrtofo 10
Se€ I'i CCompre€sorCont ols
1
ALKAED
a
c352
f BLKaEou Y 9,;%,.cFN I vIEw 5e
;
"'
T
";::-:.."-!
Y:. ---::Y h!ii'in"," :
I : ""'I 'is.2o) :
I i,o''ur,ff;, l;l:'l?'* i
I r- - -, |JBEI :
I ; I control | ;
I :L--J :I ' PoWERTRAIN ordu. ' ENGINE CONTROL '' MODULE
: (PCMoTECM) :I PHAfO 86I wEw 7allqA ----.ENGINECOOLANTTEMPERATUREswtrcH BLLPHO|O 33 ?
Ses GrolndDiskibution,oaqe 14.
,I
H
:I
i:
"'*
1_l
c7531
BLU/BLK
ALK2
BLK
RADIATORFANMOTORI
BLK
BLK1
ELK
c753
CONDENSERFANMOTOR
a
* czsr
page 14.
II
FJ'Glot
c211
Gro!nd
T
Se€ GroundOstribution,Pago 14.4"t1 - '96.f98: All models'99-'00: 016Y5 with M/I 01685"2 = '99-'00: Allmodels exceptD16Y5 with M/T and 01685
cof{oENs€R
* czor33123lCVIl
63

- How the Circuit Works
Radiator Fan
Voltage is provided at all times to the radiator fan
relay (contacts) through fuse 57. With the ignition
swilch in ON (ll), voltage is provided to the coil of
the relay through luse 17.
The radiator tan relay can be grounded through
either the engine coolant temperature switch or the
engine control module (ECM) or powertrain control
module (PCM).
The engine coolant temperature switch grounds
the radiator fan relay (coil) when the engine
coolant temperature exceeds 199'F (83'C). The
switch opens when coolanl temperature
decreases 3'- 8'C.
Condenser Fan
Voltage is provided at all times to the condenser fan
relay (contacts) through fuse 56. With the ignition
switch in ON (ll), voltage is provided to the coil of
the relay through fuse 17. When you push the A'lC
switch and put the heater fan switch in 1, 2,3, o( 4
position, the ly'C thermostat comes on, the
condenser fan relay energizes, and the condenser
fan motor runs.
A,/C Thermostat
The A,/C thermostat is located on the evaporator
housing. The A,/C thermostat tums off the A/C
compressor clutch if the temperature at the
evaporator goes below 3'C (37'F). This prevents
condensation from freezing on the evaporator fins
and blocking the air delivery into the passenger
compartment. lf the temperature goes below 3'C
(37"F) tuming off the Ay'C thermostat, ground will be
removed from the condenser fan relay. This will
deenergize the relay and remove voltage from the
condenser fan motor causing the fan to stop running.
Reter to the Service Manual (Section 23, Eleckical)
for specific tests or troubleshooting procedures.
63-3

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