engine coolant temperature sensor HONDA CIVIC 1999 6.G Owner's Manual

PGM-FI System
Engine Coolant Temperature (ECTI Sensor
The scan tool indicates Diagnostic Trouble code (DTC) P0116; A range/performance problem in the EngrneCoolant Temperature (ECT) Sensor circuit.
The ECT Sensor is a temperature dependant resistor (thermistor). The resistance of the thermistor decreases as the enginecoolant temperature increases as shown oetow.
RESISTANCE(ko)
NOTE: lf DTC P0117 and/or P01'18 are stored at the same time as DTCfor DTC P0116.
Possible Cause
. ECT sensor deterioration. Malfunction in the thermostat and cooling system
Troubleshooting Flowchart
-a 32 68 r0a la0l?6 2t2 2481'rr-20 o 20 ao o D r@ Il, r'c)
ENGINE COOLANT IEMPERATURE
P0116, troubleshoot those DTCS first. then recheck
11-128
THERMISTOR
- The MIL has bogn reported on.- DTC P0116 is stored.
Problem verification:1. Start the engine. Hotd theengine at 3,000 rpm with noload (in Park or neutral) untilthe radiator fan comes on,then let it idle.2. With the scan tool, check the
Intermiftent lailure. system is OKai thi. time. Ch.ck the thc.mo-stat 6nd thc cooling system.
is 176 200'F {80 - 93'C)or0.0-0.TVindicated?
Check the thermostat and thecooling system. ll they als OK,raplace the ECT sensor.

|.
'f
fD;r.tt The scan tool indicates Diagnostic Trouble Code (DTC) P0117: A low voltage (high temperature) problem in the|jg Engine Coolant Temperature (ECTI sensor circuit.
ECT SENSOR 2P CONNECTOR (C122I
Wire side of female terminals
Substitute . lnown-good ECM/PCM .nd rocheck. It normrl ECT
is indic.ted, replaco the original
ECM/PCM,
*:'99 -Oo models except D16Y5 enginewith M/T
(cont'd)
11-129
The MIL has been ,eported on.DTC ml 1 7 is storod.
Problom vorification:1. Turn the ignition switch ON (ll).
2. Check the ECT with the scantool.
Intermittont failulo, sy3tom it OK
at thk tim., Chock for Poor oon-n.ctions or loo!. wiraa at C122IECT 3en orl and ECM/FCM.
ls 302"F (150"C) or higher {orH-Limit in Honda mode ofPGM Tester) or 0 V indicated?
Check toJ a short in the ECT s.n-5('t:1. Disconnect the ECT sensor 2P
connector.2. Check the ECT with the scanrool.
ls 302"F (150"C) or higher {orH-Limit in Hond6 mode ofPGM Testerl or 0 V indicated?
Check for a 3hort in tho wiro
IECT linel:1. Turn the ignition switch OFF.2. Disconnect the ECM/PCM con-nector D (16P) (C {31P))*.3. Check for continuity betweenthe ECT sensor 2P conneclor ter-minalNo, 1 and bodyground.
B.gair short in the wiro bltweenECM/PCM (D2 (C261'l .nd ECT
.1,

PGM-FI System
Engine Coolant Temperature (ECT) Sensor
('96 - 98 Models,'99 - 00 D16YS engane with M/T) (cont'd)
The sc€n tool indicates Diagnostic Trouble Code (DTC) P0118; A high voltage (low temperature) problem in theEngine Coolant Temperature (ECT) sensor circuit.
ECt SENSOR 2P CONNECTOR {C1221
ECTIRED/WHTI
JUMPER WIRE
sG2(GRN/BLK)
Wire side of female terminals
ECM/PCM CONNECTOR D Il6PI
sG2 tGRN/81r0
Wire side of Iemale terminals
- Tho MIL ha3 bcen r€oorted on.- OTC m118 b stored.
Problom vorificttion:1. Turn the ignition switch ON (ll).
2. Check the ECT with the scantool.
Intcrmitt.nt failui.. rydom is OKat thir timc. Chack for Door con-naction! or loor! wiaar at C122IECT ..n.orl .nd ECM/rcM,
ls -4"F (-20'C) or less (or L-Limitin Honda mode ol PGM Tester) or5 V indicated?
Chsck lor sn open in thc ECT 3an-soa:1. Disconnect the ECT sensor2P connector.z. Lonnecr rne ELt sensor zFconnector terminals No. 1 andNo.2 with a jumper wire.3. Check the ECT with the scantool.
ls -4'F (-20'C) or loss (or L-Limitin Honda mode ol PGM Testerlor5 V indicated?
Chack for an opon in the wire.{ECT, SG2lin..l:1. Turn the ignition switch OFF.2. Connect ECM/PCM connectorterminals D2 and D11 with ajump€rwire.
3. Turn the ignition switch ON (ll).4. Check the ECT with the scantool.
ls -4'F 1-20'Clor less (o. L-Limitin Honda mode ol PGM Tester)or5 V indicated?
Reprir oprn in tha wirar bstwoonCCM/PCM IDZ Dl1) .nd EGT rcn-aor.
Sub3titut. s known-good ECM/FCM and r.chcck, It normel ECTi! indicatod, roplaco tho origin.lECM/PCM.
JUMPER WIRE
1 1-130

PGM-FI System
t
I
Engine Coolant Temperature (ECT) Sensor
('99 - 00 Models except Dl6Y5 engine with M/Tl
The scan tool indicates Diagnostic Trouble Code (DTC) P0118: A high voltage (low temperature) problem in the
Engine Coolant Temperature (ECT) sensor circuit.
ECT SENSOR 2P CONNECTOR {C122)
ECT(RED/Wr{T)
JUMPER IVIRE
sG2{GRN/BLK)
wire side of female terminals
ECM/PCM CONNECTOB C 131PI
The MIL has been reported on,
oTC P0118 is stored.
Problem verilication:1. Turn the ignition switch ON (ll).
2. Check the ECT with the scan
tool.
lntormittent failuro, systom is OK
at thb timo. Check lor poor con'nections or 10036 wiraa at C122
{ECT ssnsorl and ECM/rcM.
ls -4'F (-20"C) or less lor L-Limit
in Honda mode o{ PGM Tester) or
5 V indicated?
Check for an open in the Efi sen'
sori1. Disconnect the ECT sensor 2P
connector,2. Connect the ECT sensor 2P
connector terminals No, 1 andNo. 2 with a jumper wire.3. Check the ECT with the scantool.
ls -4"F 1-20"C) or less (or L-Limit
in Honda mode of PGM Tester) or
5 V indicated?
Check for sn open in the wires
IECT. SG2 linesl:1. Turn the ignition switch OFF.2. Connect ECM/PCM connectorterminals C18 and C26 with ajumper wire.3. Turn the ignition switch ON (ll).
4. Check the ECT with lhe scantooi.
Rspair opon in th6 wiros bstwoon
ECM/PCM (Cl8, C26l and ECT
3ensot.
ls -4'F {-20"C) or less (or L-Limit
in Honda mode of PGN4 Tester) or
5 V indicated?
Substitute 6 known-good ECM/PCM and recheck. l{ no.mal EcT
is indicatod, .eplace the originalECM/PCM.
JUMPER WIRE
Wire side of female terminals
11-131

\
EVAP CONTROLCANISTER VENT SHUTVALVE 2P CONNECTOR IC141I
Wire side of temale terminals
ECM,/PCM CONNECTORS
tG1IBLK/WHT}
A973X -
0/r1 - XXXXX
Wire side of femaletermrnats
\
?,T-t
fl
VACUUMPUMP/GAUGE, 0 -30 in.Hg
\(cont'd)
11-289
{From page l1 288}
{To page 11-290)
Ch€ck the vac[um when cold:1, Disconnect the vacuum hoseshown from the EVAP controlcanister and connect a vacuumgauge to the hose.2. Start the engine and allow it
to idle.NOTEi Engine coolant temperature must be below 154"F(68'C) or Ay'C switch OFF.3. Ouickly raise the engine speedto 3,000 rpm.
(From page 11-288)
Check for an open in tha wire(lGt linol:1. Turn the ignition switch OFF.2. Disconnect the 2P connectorfrom the EVAP control canis-ter vent shut valve.3. Turn the ignition switch ON lll).4. Measure voltage between theEVAP control canister vent shut
valve 2P connector terminalNo.2 and bodyground.
Repair open in the wire betweenthe EVAP control canister ventshut valve .nd the No. 15 ALTER-NATOR SP SENSOR {7.5 A)fu3e.
ls there battery voltage?
Ch€d( for an op€n in the wiie IVSVlinel:1. Turn the ignition switch OFF.
2. R€connect the 2P connectorto the EVAP control canistervent shut valve,3. Turn the ignition switch ON (ll).
4. Measure vo ltage betweenECM/PCM connector termi-nals A4 and 82.
Repair open in the wire bctweenthe EVAP control canistor ventshut valve and lhe ECM/PCM{44t.
ls there battery voltage?
Rcolaco tho EVAP control canis.t6r vent shut valvo.
a t32P)
-

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

Description
Electronic Control System ('99 - 00 Modelsl (cont'dl
Grade Logic Control System
How it works:
The PcM compares actual driving conditions with memorized driving conditions. based on the input from the vehiclespeed sensor, the throttle position sensor, the manifold absolute pressure sensor, the engine coolant temperature sensor,the brake switch signal, and the shift lever position signal, to control shifting while the vehicle is ascending or descendinga slope.
Ascending Control
When the PCM determines that the vehicle is climbing a hill in E position, the system selects the most suitable shiftschedule (pulley ratio) according to the magnitude of a gradient. so the vehicle can run smooth and have more powerwhen needed. There are three ascending modes with different shift schedules according to the magnitude ot a gradient inthe PCM.
Descending Control
when the PCM determines that the vehicle is going down a hill in E position. the system selects the most suitable shiftschedule (pulley ratio) according to the magnitude of a gradient. This, in combinstion with engine braking, achievessmooth driving when the vehicle is descending, There are three descending modes with different shift schedules accord-ing to the magnitude of a gradient in the PCM.
L
14-206

Connector ldentification and Wire Harness Routing
Engine Wire Harness lD16Y5, D16Y8 enginss): '96 - 98 models
Connector or
Torminal
Numbsr of
CavitissLocationConnects toNot€s
c 101c102c103c104c104c105c106c107c108c 109c110c111c112c113c114c115c116cl17c118c119c120cl21
c122c123cl23c124
c125
c127c12Ac129c130c131c132c 133c134c135
c136
c138c139c140c 141c142c 143c144cl44c145c'146cl47
10
1
22
14l4322l0I
2
2
2
2120
3l
14
14
1222
2
2
22
Left side of engine compartmentMiddle of engineMiddle of engineLeft side of engine companmentLeft side of engine compartmentMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of enginefvliddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineLeft side of engine compartmentMiddle of engineMiddle of engineMiddle of engineMiddle of engine
Middle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineRight side of engine companmentBehind right kick panelUnder right side of dashUnder riOht side of dashUnder right side of dashUnder right side of dashUnder right side of dashUnder right side of dash
Under right side of dash
Under right side of dash
Middle of engineMiddle ot enginel iddle of engineMiddle of engineMiddle of ongineMiddle of engineLeft side of engine compartmentMiddle of engineMiddle of engineRight side of engine compartmentRight side of engine compartmentRight side of engine compartment
USACanada
Afi
USA
-' (A/r)
Main wire harness (C303)Crankshaft speed fluctuation (CKF) sensorEngine oil pressure switchAlternatorAlternatorNo. 'l fuel injectorNo. 2 fuel injectorNo.3 fuel injectorNo. 4 fuel injectorIAC valveThrottle position (TP) sensorl\4anifold absolute pressure (MAP) sensorIntake air temperature (lAT) sensorPower steering pressure {PSPI switchEVAP purge control solenoid valveJunction connectorJunction conn€ctorVehicle speed sensor {VSS}Countershaft speed sensorEngine coolant temp€rature (ECT) switch ADistributorEngine coolant temperature (ECT) sendingunrtEngine coolant temperature (ECT) sensorPrimary HO2S (sensor'l)Primary HO2S (sensor 1)Back-up light switchLock-up control solenoid valveSecondary HO2S (sensor 2)Mainshaft speed sensorLinear solgnoid valveShift control solsnoid valveStarter solenoidJunction connectorMain wire harnesE (C446)ECM/PCMPCMECMiPCMECM/PCMMain wire harness (C305)
Main wire harness (C305)
Main wire harness (C305)
Knock sensor (KS)IAC valveVTEC solenoid valveVTEC pressure switchEVAP control canister vent shut valveEGR control solenoid valveSecondary gear shaft speed sensorEGR valveEGR valveDrive pulley speed sensorSolenoid connector {CVT)Driven pulley speed sensor
*, (M/T)M/T*" INT\
*, tAtf)
NT:'96 model*,(A,/T):'97 - 98mooets
moqets
M/T
-1 (l,/T)*, (A,/T)-,(4,/T)*1 {M/T)*, (A,/T)*1 (CW)*, (A,T)
T101r102Left side of engine companmentRight side of engine companmentAlternatorUnder-hood fuse/relay boxG 101Middle of engineEngine ground, via engine wire harness
2
*1: Dl6Y5 engine*2: D16Y8 engine*3: D16Y5 (Ay'T), D16Y8 engines
3-16

Gonnector ldentification and Wire Harness Routing
Engine Wire Harness (D16Y5, Dl6Yg engines): ,99 - 00 models
Connectot or
Terminal
Number ot
CavitiesLocationConn€cts toNotes
c'101cl02c103c104c 104c10s
c107c 108c'r09c110c111cl12c113cl14c l15c116cl17c118c119c120cl20c121
c122c123c123cl23cl24c124c125
c127c12Ac129c 130c131cl32c133c 134c135c137c138c 139c 140c142c143c144cl44c145c146c147
103,]
322223332221414322'10
8,l
2484224222120
32
2212223
282
No. 1 luel injector INo.2 fuel injectorNo.3 fuel injector ]No. 4 fuel injector iIAC valve I anThrottle position lTP) sensorManifold absolute pressure {MAP) sensor IIntake air temperature (lAT) sensor IPower steering pressure (PSP)switch USAEVAP purge control solenoid valve ]
Main wire harness 1C303)Crankshaft speed fluctuation (CKF) sensorEngine oil pressure switchAlternatorAlternator
Left side ot engine compartmentlvliddle of engineMiddle of engineLeft side ot engine compartmentLeft side of engine compartmentMiddle of engineMiddle ot engineMiddle of engineMiddle of engineMiddle oI engineMiddle of engineMiddle of engineMiddle of engineMiddle of engineNliddle of engineMiddle of engineMiddle of engineMiddle of engineRight side of engine compartmentMiddle of engineMiddle of engineN4iddle of engineMiddle of engine
Middle of engineMiddle ot engineMiddle ot engineMiddlo of engineMiddle of engineMiddle ot enginelrliddle of engineMiddle of engineMiddle oI engineMiddle ot engineRight side of engine compartmenlBehind right kick panelUnder right side of dashBehind right kick panelBehind right kick panelBehind righr kick panelBehind right kick panelMiddle ot engine[,liddle of engineN4iddle of engineMiddle of engineMiddle oI engineLeft side of engine compartmentMiddle of engineMiddle of engineRight side ol engine compartmentRight side of engine companmentRight side of engine compartment
USACanada
Junction connectorJUnct|On COnnectorVehicle speed sensor lVSS)Countershaft speed sensorEngine coolant temperature {ECT} switch ADistributorDistributorEngine coolant temperature (ECT) sendingunitEngine coolant temperature (ECT) sensorPrimary H02S (sensor 1)Primary HO2S (sensor 1)Primary HO2S lsensor 1)Back-up light switchLock'!p control solenoid valveSecondary HO2S (sensor 2)Mainshaft speed sensorLinear solenoid valveShift control solenoid valveStarter solenoidJunction connectorMain wire harness (C446)ECM/PCMECM/PCMECM/PCMPCtvtKnock sensor (KS)IAC valveVTEC solenoid valveVTEC pressure switchEGR control solenoid valveSecondary gear shaft speed sensorEGR valveEGR valveDrive pulley speed sensorSolenoid connector (CVT)Driven pulley speed sensor
*' (A/TI
*1 (CVT)*, (M/T)
Mfia (A/Tl
" (A,/T)., (4,/r)-' {AlrJ
*1 (M/T)
tvliT
*1 (CVT)*, (cvT)*' (cw)*1 (MiT)*1 {CVT)*1 {CVT)*, (cvr)
T101T102Left side of engine companmentRight side ot engine companmentAlternatorUnder'hood fuse/relay boxG 101Middle of englne IEngine ground, via engine wire harness*1: 016Y5*2: D16Y8*3: Dl6Y5
engineengine(CW), D16Y8 engines
23-14

Gonnector ldentification and Wire Harness Routing
Engine Wire Harness {D16Y7 engine}: '96 model
Conneclor or
Terminal
Number ot
CavhiesLocationConnects toNotes
c101
c102
c 103
c104
c104
c105
c'r06
c107
c 108
c 109
c110
c111
c112
c l13
c't14
LttS
cl16
cl17
c118
cl19
c120
c121
c123
c124
c124
c125
c126
c't27
c12a
c129
c130
c131
c132
c133
c134
c135
10
1
4
5
'14
14
10
1
,,
2
2
1
22
31
16
No. 1 fuel injector INo. 2 fuel injector
No. 3 fuel injector INo,4 fuel injector
IAC valve l
Throttle position (TP)sensor IManifold absolute pressure (MAP) sensorIntake ai. temperature (lAT) sensor ]Power steering pressure (PSP) switch I USAEVAP purge control solenoid valve IJunction connector
Junction connector IVehicle speed sensor (VSS) |Countershaft speed sensor AlTEngine coolant temperature (ECT) I
Main wire harness (C303)
Crankshaft speed fluctuation (CKF)
sensor
Engine oil pressure switch
Alternator
Alternator
switch A
Distributor
Engine coolant temperature (ECT)
sending unit
Engine coolant temperature lECT) sensor
Primary H02S (sensor 1)
Back-up light switch
Lock-up control solenoid valve
Secondary HO2S (sensor 2)
Mainshaft speed sensor
Linear solenoid valve
Shift control solenoid valve
Staner solenoid
Junction Connector
Main wire harness {C446)ECM/PCM
PCM
ECM/PCM
ECM/PCM
Left side of engine compartment
Middle of engine
Middle of engine
Left side of engine compartment
Left 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
Middle of engine
Left 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
Middle of engine
Right side of engine compartment
Behind right kick panel
Under right side of dash
Under right side of dash
Under right side of dash
Under right side of dash
Under right side of dash
USA
Canada
M/T
AtJ
Afi
T101
T102
Left side of engine compartment
Right side of engine compartment
Alternator
Under-hood fuse/relay box
G101Middle of engineEngine ground, via engine wire harness
23-20