
Fuel and Emissions
Spocial Tools ................ 1 1-2
Compon€nt Location
lndex ................. ...... 11-3
System Description
Vacuum Connectiona .......,.................... 1 1 -8
Efectrical Connections ....,.,.,......,...,,.....,'11-12
Syst€m Connectors ...,...,.................-.--. 11-2O
T.oubloshooting
Troubleshooting Guido .......................... 1 1-32
Self -diagnostic Procedures .,..,............... 1 1 -34
How to Road Flowcharts ...................,... 11-39
PGM-Fl System
Systom Description .............................. 1 l-4O
Troubleshooting Flowcharts
Engine Control Moduls ............... ........... 1 1 -42
Heated Oxygon Sensor ......,.................. 1 1-46
Heated Oxyg€n Sonsol Heatel .....,......... 1 1 -47
Fuel Supply System ..............-............... 1 1-50
Manitold Absolute Pressure
Ssnsor ............................................ 1 1-52
Top D6ad Cente./Crankshatr
Position/Cylindor Position sonsor ........ 1 1 -56
Engine Coolant Tempsrature Sonsor ....... 11-58
Throttlo Position Sonsor ........,..,,........... 1 1-60
Intake Air Temperaturs Sensor ............... 11-62
Baromet c Prsssuro Sensor ......,...,...,..,. 11-64
lgnition Output Signal ........................... 1 1 -66
Vehicle Spe€d Sensor ........................... 1 1 -68
Electdcal Load Dotector ....,...,..........,.... 1 1 -7O
Knock Sensor [818C1 engine] ............... 11-74
A/T Fl Signal A/B ................................. 1 1-76
ldle Contlol System
System Troubleshooting Guide .................. 1 1 -78
Systom Description ........ 11-79
Troubloshooting Flowchans
ldl€ Ail Control Valve ........................... 1 1 -82
Ail Conditioning Signal ......................... 1 1 -84
Altemator FR Signal ............................. 1 1 -86
Automatic Transaxle (A/T) Gear
Position Signal ......... 11-88
Brake Switch Signal ............................. 1 1 -9O
Startel Switch Signal ............................ 11-92
Power Steering Pressure Switch Signal ... 11-93
Fast ldle Thermo Valve ...................,......... 1 1 -94
ldls Speed S€tting .................................... 1 1 -95
Fuel Supply System
Systam Tloubloshooting Guid. .................. 1 1 -97
Fuol Linos ...................... 1'l -98
System Description ........ 11-100
Fuol Prassure ................. 11-100
Fu6l Ini6ctors ................. 11-102
Fuel Pressure Ragulato. .,. 11-106
Fuel Filter ...................... 11-108
Fual Pump ..................... 11-109
PGM-Fl Main F6lay ................................... 1 1"1 1 1
Fuel Tank ...................... t 1-114
Intake Air System
System Troubloshooting Guido .................. 1 1 -1 1 5
Systom Dascription ........ 11-116
Air Clean€r .................... 11-117
Throttls Cable ................'11-118
Throttl8 Body ................ 11-120
lntake Air Bypass Cont.ol Systsm
[B18Cl enginal .,......... 11-123
Intake Manilold [B1881 onginol ................. 11-128
Emission Control System
Systsm Troubleshooting Guido .................. 1 1 -1 29
Systam Doscription ........ 11-130
Tailpips Emission ........... 11-130
Thrae Way Catalytic Convortor ...,...,........., 11-131
Positiva CrankcaEo V6ntilation Systcm .,....., 11-134
Evaporativo Emission Contro|,..,..,.,.,,.,,..,.., 1 1-135

Component Locations
lndex
81881 sngin6:
IOLE AIR CONTROL OACI VALVEpage '11-82T
MANIFOLD ABSOLUTEPRESSURE {MAP} SENSOREVAP
THROTTLE POSITIOIII {TP) SENSORTroubleshooting, page 1 1-60
Troubleshooting,
(ECTI SENSOR HEATEO
PURGE CONTROLSOLENOID VALVETroubleshooting,11-137
THROTTLE CABLEInspection/Adiustment, page 1 1-1 18
Installation, page 11- 1 18
SENSOR lHO2S}
TOP DEAD CENTER/CRATIIKSHAFTPOSITIOf{/CYLINDER POSITION(TDC/CKP/CYP} SENSORTroubleshooting, page 1 1-56
INTAKE AIR TEMP€RATURE IIAT) SEI{SORTroubl€shooting, page 1 1 -62
POWER STEERING PRESSURE (PSP)
swtTcHTroubleshooting. page 11-93
sq
IDLE THERMO VALVEInspection, page 11-94
ELECTRICALLOADOETECTORIELD}Troubleshooting.page,l l-70
IGNITIONMODULE {ICMI
Troubleshooting, page 1 1-66
ENGINE COOLANT TEMPERATroubleshooting, page I 1-58Troubleshooting. pages 11-46, 47
11-3

Component Locations
lndex
B18Cl ongino:
THROTTLEPOSITION (TP}
SENSOR
MANIFOLD AESOLUTEPRESSURE (MAPI SENSOR
Troubleshooting, page 1 1-52
EVAPPURGE CONTROLSOLEiIOID VALVETroubleshooting,page 11-137
VALVE
INTAKE AIR TEMPERATURE
IIAT) SENSORpage 11-62
THROTTLE CABLEInspection/Adiustment, page 'l 1-1 19
lnstallation, page 1 1-1 19
IOLE AIF CONTROL (IACI VALVETroubleshooting. page 1 1 -82
Troubleshooting,page 1 1-6O
TOP DEAD CENTER/CRANKSHAFTPOSITION/CYLINDER POSITION
{TDC/CKP/CYPI SEI{SORTroubl€shooting. Page 1 1 -56POWER STEERING PRESSURE (PS'I
swtTcHTroubleshooting, page 1 1-93ELECTRICALLOADDETECTORIELD}Troubleshooting,page.1 1-70
IGNITION CONTNOL MODULE OCMI
Troubleshooting, Psge 1'l-66
ENGIT{E COOLANT TEMPERA
{ECT} SEI{SORTroubleshooting, Pag€ 1 1-58
sElrlsoR tKslTroubfeshooting, page 1 1 -7 4
HEATED OXYGEN SENSOR (HO2S}
Troubleshooting, pages 11-46, 47
FAST IDLEInspection, page 1 'l -94
11-4

D14
811812813814815
816
:wHT/nED' -'-'--''''-''-'
:j:on 2-"''''-' '- -----
:-WHT--------'-''''-''''
TDC/CYP/CKP SENSOR
c122
t{o. 2 FUELII{JECTOR
c123
No. 3 FUELNJECTOR
c124
t{o. 4 FUELII{JECTOR
:ji oRNi sLU =::::i-:jjjjjjj:ji WHT/ALU jjji-::-:-:::i:jj
YEL/ALXYELI
YEL/BLK- RED2
(cont'd)
11-15
KS
t{o. 1 FUEIII{JECTOR
EVAP PURGEcot{TRoLsoLE {otDVAIVE

Troubleshooting
Self-diagnostic Procedures (cont'dl
':818C1 engine
a lf codes other than those listed above are indicated, verifv the code. lf the code indicated is not listed above, replace
rhe ECM.
a The MIL may come on, indicating a system problem when, in fact, there is a poor or intermittent electricalconnection.
First, check the electrical connections, clean or repair connections it necessary.
o The MIL and @ indicator light may light simultaneously when the Diagnostic Trouble Code (DTC) 6, 7 or 17. Check
the PGM-Fl system according to the PGM-Fl system troubleshooting, then recheck the l!! indicator light. ll it lights,
see page 14-5O, 51.
a The MIL does not come on when there is a malfunction in the A/T Fl signal or Electrical Load Detector (ELDI circuits.
However, it will indicate the codes when the Service Check Connector is shorted.
DIAGNOSTIC
TROUBLE
CODE (DTCISYSTEM INDICATEDPsge
oENGINE CONTROL MODULE IECM)11-42
,lHEATED OXYGEN SENSOR IHO25)1 1-46
aMANIFOLD ABSOLUTE PRESSURE {MAP SENSOR)11-52
4CRANKSHAFT POSITION (CKP SENSOR)1 1-56
oENGINE COOLANT TEMPERATURE (ECT SENSOR)11-58
THROTTLE POSITION (TP SENSOR}11-60
ITOP DEAD CENTER POSITION (TDC SENSORI1 1-56
9No. 1 CYLINDER POSITION (CYP SENSOR)1 1-56
10INTAKE AIR TEMPERATURE (IAT SENSOR)11-62
13BAROMETRIC PRESSURE (BARO SENSOR}1|-64
14IDLE AIR CONTROL (IAC VALVE}11-42
tcIGNITION OUTPUT SIGNAL11-66
toFUEL INJECTOR1't-102
17VEHICLE SPEED SENSOR {VSSI11-68
20ELECTRICAT LOAD DETECTOR (ELD)'t 1-70
21VARIABLE VALVE TIMING & VALVE LIFT ELECTRONIC CONTROL SOLENOID
VALVE {VTEC SOLENOID VALVE)'6-36
22VARIABLE VALVE TIMING & VALVE LIFT ELECTRONIC CONTROL PRESSURE
SWITCH (VTEC PRESSURE SWITCHI-6-38
23KNOCK SENSOR {KS}-11-7 4
30A/T FI SIGNAL A11-76
3'rA/T FI SIGNAL B1 1-76
4'lHEATED OXYGEN SENSOR (HO25} HEATER11-47
43FUEL SUPPLY SYSTEM1 1-50
11-36

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
![HONDA INTEGRA 1994 4.G Workshop Manual PGM-FI System
TDC/CKP/CYP Sensor
_f=l_ fi_l The Malfunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code (DTC) 4: A problem int:- the Crankshaft Position (CKP) Sensor circuir.
l6]- ftl - T HONDA INTEGRA 1994 4.G Workshop Manual PGM-FI System
TDC/CKP/CYP Sensor
_f=l_ fi_l The Malfunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code (DTC) 4: A problem int:- the Crankshaft Position (CKP) Sensor circuir.
l6]- ftl - T](/manual-img/13/6067/w960_6067-246.png)
PGM-FI System
TDC/CKP/CYP Sensor
_f'=l_ fi_l The Malfunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code (DTC) 4: A problem int:- the Crankshaft Position (CKP) Sensor circuir.
l'6]- ftl - The Malfunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code (DTC) 8: A problem in-i- the ToD Dead Center ITDC) Sensor circuit.
-flG]l- ft-] The Malfunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code (DTC) 9: A problem in- , - the Cvlinder Position ICYP) Sensor circuit.
The CKP Sensor determines timing tor fuel injection and ignition of each cylinder and also detects engine speed. TheTDC Sensor determines ignition timing at start-up (cranking) and when crank angle is abnormal. The CYP Sensor detects
the position of No. 1 cylinder tor sequential fudl injection to each cylinder.
- \.--r-l - -__l_-
tPJ:;LlJ:lEl--;l ?,:
- Tho MIL hos beon roponod on.- With rho SCS short connoctorconneclod lsso pago I l-341,code 4, 8 and/or 9 ar6 in-dicated.
Do the ECM Reset procedure (seepage 11-35).
Intohittent failuro, syst€m is OKat thia tima {t6st drivo may benoceaSaayr.Chock for poo. connections orlooss wires at C222 (located atright shock towerl, C110(TOC/CKP/CYP Sonsorl and ECM.
ls the MiL on and does it in-dicate code 4, 8 and/or 9?
Turn the ignition switch OFF.
Disconnect the 8P connector fromthe TDC/CKP/CYP sensor.
{To page 1 1-57)
11-56

{From page 11-56)
Measure resistance between ter-minals of the indicated sensor.'see table
R.olac6 th. distributorhousing (8oo aoction231.ls there 35O-7O0 0?
Check for continuity to bodyground on both terminals ot theindicated sensor,
Rgplace tho di.tributorhousing llo€ loction23t.
Connect the test harness to themain wire harness only, notto theECM (see page 1 1-371.
Measure resistance between ter-minals of the indicated sensor ontest harness.'see table
Roprir opon in tho indi-cated senaoa wirea.*soo tablols there 350 70O 0?
Repair short to bodyground in tho indicrl.dt€naor wiroa.i s€e tabla
SEIiSOFDTCSENSORECMTENMINAICOLOR
2815ATU/GFN
6816BTUTVEI
TDCa813ORN/BTU
814
9B1tORN
as12
o o ooooo oo ooo o I oooooooo l6coocl o oo ooo ooooo
o oooo ooooo ooo I oooo oooo lo{nofioo't oooooooo ooo
812350-7000?
Check for continuity to bodyground on 815. 813 and/or B'l 1terminals.
ls there continuity?
NO
Substituto a known-good ECMand rechock. lf symptom/indica-tion goes away. roplaco tho origi-n.l ECM.
11-57