fuel HONDA INTEGRA 1994 4.G Owner's Guide

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

3. Fuel Cut-oft Control
a During deceleration with the throttle valve closed, current to the {uel injectors is cut otJ to improve fuel economy
at speeds over tollowing rpm:
. 8188l engine: 91O tpm (Canada model: 1,O50 rpm)
. 818C1 engine: 95O tpm (Canada model: l,O5O rpm)
a Fuel cut-olf action also takes place when engine speed exceeds, 7,O0O rpm {81 8B1 engine), 8,1O0 rpm (B 18Cl
engine), regardless oI the position of the throttle valve, to protect the engine from ovet-revving.
A/C Compressor Clutch Relay
When the ECM receives a domand for cooling trom the air conditioning system, it del8ys the compressor from being
enetgized, and enriches the mixture to assure smooth transition to the A/C mode.
Evaporative Emission (EVAP) Purge Control Solenoid Valve
When the engine coolant tempersture is below 163oF {73"C), the ECM supplies a ground to the EVAP pu.ge control
solenoid valve which cuts vacuum to the EVAP purge control diaphragm valve.
Intake Air Bypsss (lAB) Control Sol€noid Valve
When the engine rpm is below 5,750 rpm, the IAB control solenoid valve is activated by a signal from the ECM,
intske air flows through the long intake path, then high torque is delivered. At spaeds highe. than 5,750 rpm, the
solenoid valve is deactivated by the ECM, and intake air flows through the short intake path in order to reduce the
resistance in airflow.
ECM fail-safe/bEck-up Functions
1. Fail-sate Function
When an abnormality occurs in a signal from a sensor, the ECM ignores that signal and assumes a pre-progtammed
value tor that sensor that allows the engine to continue to run.
Back-uD Function
When an abnormalitv occurs in the ECM itself, the fuel iniectors are controlled by a back-up citcuit independent of
the system in order to permit minimal driving.
Self-diagnosis Function IMaltunction Indicator Lamp {MlL)1
Wh6n an abnormality occurs in a signal from a sensor, the ECM supplies ground for the MIL and stores the code
in erasable memory. When the ignition is initially turned on, the ECM supplies ground tor the MIL tor two seconds
to check the MIL bulb condition.
Two Trio Detection Method
To prevent tals€ indications, th€ Two Trip Dstection Method is used for the HO2S and fuel metering-related self-
diagnostic tunctions. When an abnormslity occurs, the ECM stores it in its memo.y. Wh€n the ssme sbnormality
recurs alter the ignition switch is turned OFF and ON ag8in, the ECM informs the driver by lighting the MlL.
However, to ease troubleshooting, this function is canc€ll€d when you short the service check connector. The MIL
will then blink immedistelv when an abnormality occurs.
4.
6.
2
4.
11-41

PGM-FI System
Heated Oxygen Sensor lHO2Sl
ztRcot{lAELEiIE'{T
HEATER
- --.'!- - -__-
lrPl _l !l-
-fi-l: The Malfunction Indicator Lamp (MlL) indicates Diagnostic Troubls Code (DTC) 1: A problsm in
/? the Heated Oxygen Sonsor (HO2S| circuit.
The Heated Oxygen Sensor IHO2S) det€cts th6 oxygon contont in th6 exhaust gas and signals th6 ECM. In operation,
the ECM receiv€s th6 signals trom the sensor and vari€s the duration during which tu6l is iniocted. To stabilize thd sen-aor's output, tho sensor has 8n intarnal heater and the sensor olemant is coatod with a catslyst. The HO2S is installod
in TWC housing (B18Cl engine) or exhaust pipe B (Bl8Bl €ngine).
sEl{SORTERMII{ALS
:tz-t6l-/ --.- \
VOLTAGE (V}sTotcHtoltETncAIR-FUEL BANO
HEATEBTEBMIT{ALSRICH - AN. - LEAI{FUELRATIO- Th! mll h.. bo.n raportad on.- Wlth thr SCS rhon coon cto.connoctad lr.. p!9. 1t-341,cod. t l. Indlcltrd.
Oo th€ ECM Res€t Procodure {soopag€ 11-35).
Stan the 6ngine. Hold th6 engine
A3,qgq rpm with no load {A/T in
Lryl or lll position, M/T in nourralluntil the radiator lan com6s on.then lot it idle lor ot least on6minutg beforo road t€6tin0.
Connoct ths SCS short connoctorto th6 sorvic€ check connectorlsoo p.g6 1 1-34).
Rood t€st witlthe automatictransmission in L?l position (M/T:4th gear).Stsrting st l,600 rpm, acc6lorateu6ing wide open throttlo for atlesgt 5 seconds. Thsn dgcol€rstefor at lorst 5 s€conds with th€throttlo completoly closed.
Intarmittd[ t llurc, lyri.m b Of!l thla tlmc. Ch.ck lor poor con-nacdona o? loota wlrat |l C223(loc.trd at right $ock towo.l,Cr 13 (HO2S| lnd ECM.
Ooes the MIL blink and doos itindic6t6 cod6 1?
Go to plga and partonn tad fotcod. 43 lr.a p.go l1-501.
1 1-46

PGM-FI System
rj-t
--t-.
Fuel Supply System
-+-lt@t- -t 13 |- ' "- - --i--
T,-n The Maltunction Indicator Lamp (MlL) indicares Diagnostic Trouble Code (DTC) 43: A problem in
- L:!-i - the Heated Oxygen Sensor (HO2S) circuit. or a probtem in the Fuel Supply System.
NOTE:. Use DIGITAL MULTIMETER.. U6e 2 Volt rang6.
o oooooo oooooo I oo oooooooooooooooooooQoo ooo ooooo I oooo ooooooooooooooo
426
JUMPER WIRE
o ooooo oooo ooo I oo oooooo Isdtcllodsl ooo ooooooooo oooo ooo oo ooo I oooo ooooooooooooooo
D14 {+l
I
426 t-l vohrgo rhould rl.n.t
| 0.4-0.5 V wh.n th..- ignirioo .wilch i! firdt|rtrod o.r, Itd docr!6ato b.low O.1 V in L..th6n two minutaa.
- Tho MIL h.s boen reportod on.- With rhe SCS short con-noctor connocted (soo paga1l-34), codo 43 b indlcat.d,
From codr I troebl.-lhoorlng lprgo 1146).
ls the code 43 accompanied bythe MIL and poor driveability?Go to Fuol Supply .y.t.m (|ecpag6 1t-971.
Do the ECM Reset ftocedure lseepage 11-35).
Connect the SCS short connectorto the service check connector{see page 'l1-34).
Start the engine. Hold the engineat 3,00O rDm with no load {A/T in
@or@ position, M/T in neutral)until the radiator Ian comes on,then let it idle for at least onemanute,
Intonnitl.nt t llure, tydom lr OKat thi. tim. lto.t drlv. mly b.nocaararyr.Chock lor poo? connactlona otloots wiro at C223 lloc.t.d atrlghl lhock towo.]. Cl13lHO2Sland ECM,
Raise the engine speed to 3,000rpm and hold that throttle positiontor at least one minute.Do not vary the throttle positioneven if the rpm drops.
Ooes the MIL blink and does itindicate code 43?
Turn the ignition swilch OFF.
Connect the test harness betweenthe ECM and conneclors {seepage 1 1-371.
With the ignition switch OFF, waitfor at least two minutes.
lnstall a jumper wire on the testharness between A6 and A26.
11-50
1To page 1 1-5'l l

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

Fuel Supply System
System Troubleshooting Guide
NOTE: Across each row in the chart, the sub-systems that could be sources of a symptom ara tanked in tho order they
should be inspected starting with O. Find the symptom in the left column, read across to the most liksly source, then
refer to the page listed at the top of that column. lf inspection shows the system is OK, try the next most liksly system
@, etc.
PAGE
SYI\4 PTOM
FUEL
LINES
FUEL
INJECTOR
FUEL
PRESSURE
REGULATOR
FUEL
FILTER
FUEL
PUMP
PGM-FI
MAIN
RELAY
CONTAM'
INATEO
FUEI
11-9811-1021 1,106l1-toa11-109t'l'nl
ENGINE WON'T START@o@
DIFFICULT TO START
ENGINE WHEN COLD OR HOTo\4
ROUGH IDLEo@
POOR PER.
FORMANCE
MISFIRE OR
ROUGH
RUNNINGo@@
FAILS
EMtSSION@o
LOSS OF
POWER@@o
FREOUENT
STALLING
WHILE
WARMING
UPo
AFTER
WARMING
UPo
11-97

Fuel Supply System
Fuel
NOTE:Check all fuel system lines and hoses for damage, leaks or deterioration, and replaco if n€cessery.
11-98

The fusl supply system consists ot a fuel tank, in-tank
high presssure fu6l pump, PGM-FI main relay, fuel filter,
tuel pressure regulatot, fuel inioctors, fusl pulsation
damper and fuol delivery and return linss. This system
delivers pressure-regulatored fu6l to the fu6l injectors and
cuts the fuel delivory wh6n the engine is not running.
Fuel Supply System
System DescriptionFuel Pressure
a Do not smok6 while working on the fuol syst6m,
Keep open flames or spalks away tlom your work
aroa.
a 8e sure to raliavo fuol p.essur6 while th6 6n9in6 is off.
NOTE: Eefore disconnecting fuel pipes or hoses, release
pressure from the system by loosening the 6 mm se.-
vice bolt on top of the fuel filter.
1 . Disconnect the battery negative cable from the bat-
tery negative terminal.
NOTE: The LS and GS-R model radio may have a
coded theft protection circuit. Be sure to get the cus-
tomer's code number betore disconnecting the
batterv,
After service, reconnect Dowe. to the radio and turn
it on. When the word "CODE" is displayed. enter
the customer's s-digit code to restore radio
ooeration.
2. Remove the fuel fill cap.
3. Use a box end wrench on the 6 mm service bolt at
the fuel tilter, while holding the special banjo bolt
with another wrench.
4. Place a rag or shop towel over the 6 mm service bolt.
5. Slowly loosen the 6 mm service bolt one complete
turn.
NOTE:
a A fuel pressu.e gauge can be attached at the 6
mm seryice bolt hole.
a Alwavs replace the washer between the service
bolt and the special banio bolt. whenever the ser-
vice bolt is loosened.
a Replace all washers whenever the bolts are
removeo.
SERVICE BOLT15 N.m(1.5 kgf.m,11 rbr.ftl
FUEL FILTER
1 1-100

Insp6ction
1. Relieve fuel pressure (see page 11-1OO)
2. Remove the service bolt on the tueltilter while hold-
ing the banjo bolt with another wrench. Attach the
special tool
3. Siart the engine. * Measure the {uel pressur€ with
the engine idling and vacuum hose of the fuel pres-
sure regulator disconnected from the tuel pressure
regulator and pinched.
Pressure should b€;
818B1 engins:
275-324 kPa (2.8-3.3 kgl/cm2, 40-47 psil
818C1 ongine:
329-37a kPa (3.35-3.85 kgf/cmz, 48-55 pei)
4. Reconnect vacuum hose to the tuel plessure
regulator.
Prossuro should b€;
Bl8Bl ongino:
216-245 kPa (2.2-2.5 kgf/cm', 31 -36 psil
B18Cl on9in6:
27O-319 kPa 12.75-3.25 kgt/cm', 39-46 psi)
FUEL PRESSURE GAUGE07406 - OO4000 1
lf the engine will not stan, turn the ignition switch
on. wait for two seconds, turn it off, then back on
again and read the fuel pressure.
CLAMP
a lf the fuel pressure is not as specified, first check the
fuel pump (see page 1 l - 1 1O). lf the fuel pump is oK,
check the following:
- lf the fuel pressuro is higherthan specified, inspect for:
. Pinched or clogged tuel return hose or line.
. Faulty fuel pressure regulator (see page 11-106)
- It the fuel p.essu.e is lower than specitied, inspect fo.:
. Clogged fuel tilter.. Faulty fuel pressure regulator (see page '11-106).
. Leakage in the fuel line.
1 1-101