1994 HONDA INTEGRA coolant temperature

PGM-FI System
System Description
ENGINE CONTROL MODULE (ECMIOUTPUTS
PGM-Fl System
The PGM-Fl system on this model is a sequential multipon fuel injection system,
Fuol Iniector Timing and Duration
The ECM contains memories tor the basic discharge durations at various engine speeds and manifold pressures. Thebasic discharge duration, after being read out from the memory, is turther modilied by signals sent from vanous sensofsto obtain the final discharge duration.
ldle Air Control
ldle Air Control Valve (lAC Vatve)
When the engine is cold, the A/C compressor is on, the transmission is in gear (A/T only) the brake pedal is depressed,the P/S load is high, or the alternalor is charging, the ECM controls current to the IAC Valve to maintain correct idle soeed.
lgnition Timing Controla The ECM contains mamories for basic ignition timing at various engine speeds and manifold pressures. lgnition timingis also adjusted for engine coolant temperature.a A Knock Control System is also used. when detonation is detected by the knock sensof. the ignition timing is retarded(B18Cl engine).
Other Control Functions
1. Starting Control
When the engine is started. the ECM provides a rich mixture by increasing fuel injector duration.2. Fuel Pump Control
a When the ignition switch is initially turned on, the ECM supplies ground to the PGM-Fl main relay that suppliescurrent to the fuel pump tor two seconds to pressurize the tuel system.a When the engine is running, the ECM supplies gfound to the PGM-Fl main relay that supplies current to the fuel pump.a When the engine is not running and the ignition is on, the ECM cuts ground to the PGM-FI main relav which cutscurrent to the fuel pump.
TDC/CKP/CYP Sensor
MAP Senso.
ECT Sensor
IAT Sensor
TP Sensor
HO2S
vss
BARO Sensor
ELD
Starter Signal
ALT FR Signal
Air Conditioning Signal
A/T Gear Position Signal
Battery Voltage {lcN. 1)
Brake Switch Signal
PSP Switch Signal
Knock Sensor'
VTEC Pressure Switchr
Fuel-lnjectors
PGM-FI Main Relay (Fuel Pump)
MIL
IAC Valve
A/C Compressor Clutch Relay
Radiator Fan Relav
Condenser Fan Relav
ALT
rcM
EVAP Purge Control Solenoid
HO2S Heater
VTEC Solenoid Valve'
IAB Control Solenoid Valve*
lFuet tnjector Timing and Duration]
I Electr..l"ldle Contr;il
Fit'e' contr; Funcrfit
l6tio; Ttntrlg c..trol
tEcM aack-,rp Functiorlsl
': 818C 1 €ngine
11-40

PGM-FI System
Engine Coolant Temperature (ECT) Sensor
- ,-!-- ---1- -
t@l- -l 6 | The Malfunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code (DTC) 6: A problem in- - the Engine Coolant Temperature (ECT) Sensor circuit.The ECT Sensor is a temperature dependant resistor (thermistor). The resistance oI the thermistor decreases as th€ en-gine coolant tempe.ature increases as shown below.
J rsG-11
RESISTANCE{k0l
- \.--r-l--t 5 | /--i- \
j 32 68lOrr la0 t76 2t2 2a8 (.Fl-2tt 0 20 rto ao D r@ t20 (,cl
ENGII{E COOLAI{T TCMPERATURE- Th€ MIL has boon roDortod on.- Wlth tho SCS shon connoctorconnoctod {s66 pag6 '11-34},
code 6 is indicatod.
Do the ECM Reset Procedu.e lseepage 1 1-35).
Turn the ignition switch ON.
Intoimittont failur6. ryatom is OKel this lime ltosl d.ive may bonocassaryl.Chock for poor connsctiona orlooso wiros al C223 {locatod attight shock lowor, C111 (ECT
sonsorl, C419 {TCMI and ECM.
ls the MIL on and does it indi-cate code 6?
Start the engine. Hold the engineat 3,O0O rom with no load {Afi in
N or lF]position, M/T in neutral)until the radiator lan comes on,then lot it idle.
Turn the ignition swirch OFF.
Disconnect the 2P conneclor lromthe ECT sensor.
Measure resistance between the2 terminals on the ECT sensor.
ls there 2OO-4OO O?
(To page 1 1-59)
11-58
--

ldle Control System
System Description (cont'd)
1 . Atter the engine slarts. the IAC valve opens for a censin time, The amount ot air is increased to raise the idle soeedabout 15O-3OO rom.
2. When the coolant temperature is low, the IAC valve is opened to obtain the proper fast idle speed. The amount ofbypassed air is thus controlled in relation to the engine coolant temperature.
IDI-E SPEEDlrpm)
176
80
ENGINECOOLANT TEMPERATURE
t"Fl(oct
11-80

Description
Electronic Control System (cont'd)
. GRADE LOGIC CONTROL SYSTEM
How it works:
The TCM compares actual driving conditions with driving conditions memorized in the TCM. based on the input trom
the vehicle speed sensor, throttle position sensor, engine coolant temperature sensor, brake switch signal and select
lever position signal, to control shifting while a vehicle is ascending or descending a slope. or reducing speed.
SIGNALS DETECTED
Dliving ResistanceJudgement of Controlling Area
Engine Coolant
TemDerature Sensor
. Flat road mode. Asconding mode
(Fuzzy logic). Gradual Ascending
mode. Steep Ascending
14-20

Component Location
)/
,/s\
{7v
A0t
AUTOMATIC TRANSAXLE IA/TIGEAR POSITION SWITCH
VEHICLE SPEEDSENSOR {VSSI
COUNTERSHAFTSPEED SEf{SORMAINSHAFT SPEEDSENSORTHROTTLE POSITION (TP}SENSOR
at
,
)''ENGINE COOLANT TEMPERATURE (ECTISENSOR
14-45

Electrical
Special Tools
Troubleshooting
Tips and Precautions ................................ 23-3Five-stop Tloubleshooting ..............,...-..-... Z3-sSchematic Symbols ................................_. 23-6wire Color Cod€s ..................................... 23-6Relay and Control Unit Locations
Engine Compartment .........,............ ... --. 23-7Dsshboard and Door ..,,......................... 23-gDashboard and Floor ............................. 23-t OOuaner Panel .....-.....23-12Connector ldentification and WireHarness Routing ........ 23-i 3
Index to Circuits and Systems
Airbag ............... ...-..-... 2g-26sAir Conditioning ....,.. Section 2lAltelnator ......_.............. 23-99Anti-lock Brake Systsm (ABS) Section 19Automatic Transmission Section 14Battery .............. .......... 23-66Chafging System ........... 23-98rCigalstte Lighter .....................-...-......-..-.. Z3-2O4Cfock ................. ..........23-197rcruise Controf .......--..-... 23-242Distributor .................... 23-87Fan Controls ................. 23-1ogFuel and Emissions ... Section 1i*Fuses
Under-dash Fuse/Relay Box ................... 23-48Undor-hood ABS Fuse/Retay Box ............ 23-51Under-hood Fuse/Relay Box,.................. 23-52rGauges
Engine Coolant Temperature {ECT)Gauge ................ ..23-126Fuef cauge ............... 2g-123'Gauge Assembly ....--.23-113Speedometer .....-...,,. 23-114Tachometer .....,.....-.. 23-114Ground Distribution ........ 23-60Heater ,,,........,.... ..... Section 2lrHorn ................. ........... 23-199*fgnition Switch ............. 23-70fgnition Syst6m .......-..-.. 23-A7lgnition Timing .............. 23-89Indicator Lights"A/T Gear Position .............. ................... 23-1 32B1ak6 System ...,..,..-.23-127Engine Oil Pressura .............................. _ 23-1 51Low Fuel ............ ......23-125Malfunction Indicator Lamp {MlL} ...,,. Section I l
tfnteglated Control Unit ...29-144*lnterlock System ...................................... 23-1 3gLights, Exteriol
Back-up Lights ........... 23-179Brake Lights .............. 23-t8ltDaytime Running Lights {Csnada} ........... 23-156Front Palking Lights ............................. 23-1 65Flont Side Marker Lights ....................... 23-165Front Turn Signal Lights ........................ 23-1 65*Hazard Warning Lights .........................- 2g-1A4Headlights ................. 23-t6tLicense Plate Lights .............................. 23-1 69Taillights(Harchback) .......... 23-166
{Sedan) .............. .. 23-167Lights. Inteliol
Cargo Area Light {Hatchback) ...... -.. -.. -... 23-177Ceifing Light ........-..-.23-175
Dash Lights Blightness Controt .............. 23-t70Glove Box Lighr ................................... 23-1 69Spotfighr ............ ....-.23-174Trunk Light (Sedanl ............... .............. - 23.-177*Lighting Sysrem .......-.-... 23-152:Moonroof ,,.,.......,..,,,,,.-.23-211PGM-FI Systom ........ S€crion 11Power Distribution .,.-..--..23-54Power Door Locks .............,,..................... 23-233Power Mirors ..,..,....-...- 23-216Power Relays ...........,..... 23-68Power Windows ............ 29-222*Rear Window Defogger ........,... ..........,..... - 23-20,6Reminder Systems
Key-in Remindel System ....,.............,.... 23-1 50Lights-on Reminder System ................... 23-l 5f*Maintenance Reminder system ..,,.... -.. - -. 23-.1 2gSeat Belt Reminder System ..................- 23-125*Side Markel/Turn Signal/Hazard
Ffasher System .,..,..-.23.-1A4Spark Pfugs .........-...-..... 23-97Starting System ....,,.....-. 23-73*Stereo Sound System ...,.......................,,.. 23-l gg
Supplemental Restraint System {SRS} ......... 23-265Vehicfe Speed Sensor {VSS) .............--..-.... 23-122*Wiper/Washer Systom ...............--.........-..- Zg-254
rRead SRS pi€cautions on Page 23-271 betore workingin these areas.
-+

Gonnector ldentification and Wire Harness Routing
Engine Wire Harness {B1881engine)
Connector 01
Terminal
Number of
CavitiesLocationConnects ioNotes
c10'l
c102
c103
c104
c 105
c106
c107
c108
c108
c109
c110
c111
c113
c114
c115
Lt to
c117
c118
c119
c't 20
c121
c122
c123
cl24
c125
c't26
c127
c128
c129
c130
10
14
6
1
1
2
2
8
2
3
t
1
2
2)
2
8
14
2
2
Right side of engine compartment
Right side of engine compartment
Right side of engine compartment
Right side ol engine compartment
Right side of engine compartment
Right side of engine
Right side ol engine
Transmission
Transmission
Middle of engine
lvliddle of engine
Right side ot engine
Right side of engine compartment
ldiddle rear of engine compartment
Middle of engine
Middle ol engine
Middle of engine
Middle of engine
Middle ot engine
Left side of engine
lvliddle of engine
Middle of engine
Middle of engine
Middle ot engine
Middle ol engine
Left side of engine compartment
Left side of engine compartment
Left side of engine compartment
Transmission
Transmission
Transmission
Main wire harness (C221)
Main wire harness {C222}
Main wire harness (C223)
Main wire harness {C220)
Starter solenoid
Engine coolant temperature {ECT)
sensor
Engine coolant temperature (ECT)
gauge sending unit
Back'up light switch
Lock-up control solenoid valve A and B
lgnition coil
Top dead center/Crankshaft
position/Cylinder position
(TDC/CKP/CYP) sensor
Engine coolant temperature (ECT)
switch
Vehicle speed sensor (VSS)
Heated oxygen sensor (HO2S)
MAP sensor
Throttle position (TP) sensor
ldle air control (lAC) valve
Evaporative emission (EVAPI purge
control solenoid valve
Engine oil pressure switch
Alternator
Intake air temperature {lAT} sensor
No. 'l fuel injector
No. 2 tuel injector
No. 3 fuel injector
No. 4 fuel injector
Junction connector
Engine compartment wire harness
(c304)
Engine compartmenl wire harness
(c305)
Shift control solenoid valve A and B
Countershait speed sensor
Mainshaft speed sensor
M/T
NT
NT
NT
T 101
r102
Lelt side oI engine
Right side of engine compartment
Alternator
Under-hood tuse/relay box
G 101Right side of engineEngine ground, via engine wire
harness
23-16

Gonnector ldentification and Wire Harness Routing
Engine Wire Harnoss (B18Cl enginol
Connoctor 01
Totminal
umbor ol
Cavitio8LocationConnecla tof{orc!
c 101
cl 02
c103
c104
c105
c106
c107
c108
c109
c110
c111
cl12
c113
c114
c115
c116
c117
c1r8
c119
c120
cl2'l
c122
c123
c124
c125
c't26
c'127
c 131
c132
c133
c134
2
J
4
3
'I
4
2
I
2
't4
1
4
10
14
,l
2
2
8
Right side of engine compartment
Right side of engine compartment
Right side ot engine comPanment
Right side of engine compartmsnt
Right side of engine compartment
Righr side ot engine
Right side of engine
Transmission
Middle ol engine
Middle oJ engine
Right side of engine
Right side ot engine comPartment
Middl€ reat of engine compartment
Middle of engine
Middle of engine
Middle ol engine
Middle o{ engine
Middle of engine
Lelt side ot engine
Middle of engine
Middle of engine
Middle ol engine
Middle ot engine
Middle of engine
Left side of engine companment
Lelt side ot engine compartment
Left side of engine compartment
Right side ot engine
Right sid€ of engine
Middle ot engine
Middle of engine
Main wire harness (C221)
Main wire harness (C222)
Main wire harness (C223)
Main wire harness (C22O)
Starter solenoid
Engine coolant temperature (ECT)
sensor
Engine coolant temperature {ECTI
gauge sending unit
Back-up light switch
lgnition coil
Top dead center/Crankshaft
position/Cylind€r Position(TDC/CKP/CYP) sensor
Engine coolant temperature {ECT)
switch
Vehicle speed sensor (VSS)
Hsated oxygen sensor {HO2S}
MAP sensor
Throttle position {TPl sensor
ldle air control (lAC) valve
Evaporative emission {EVAPI purge
control solenoid valve
Engine oil pressure switch
Alt€rnatot
Intake 8ir temperature (lAT) ssnsor
No. 1 fuel injector
No. 2 fuel iniector
No. 3 fuel injeclor
No. 4 fuel injector
Junction connector
Engine compartment ware harness
{c304)
Engine comPanment wire harness
(c305)
VTEC solenoid valve
VTEC oil pressure switch
Knock sensor (KS)
Intaka air bypass (lAB) control sole-
noid valve
T101
r102
Left side of engine
Right sid6 ot engine compartment
Alternator
Under-hood fuse/relay box
G 101Right side of engineEngine ground, via engine wire
harness
23-18