1994 HONDA INTEGRA check engine

Th. ll.lfunction Indicltor Lamp
lMlll at!y3 on o. cornaa on alt6ltwo aacond!.
Connect the SCS short connectorto th6 sorvice check connector(see page 11-34).
Turn the ignition switch ON.
Go to iolfdiagnostic Proceduros(se€ pago 11-34).Does the MIL indicate anv Oi-agnostic Trouble Code (DTC)?
Romove th€ SCS shon connectorlrom the service ch€ck connector.
Turn the ignition switch OFF.
Try to start the engine.
Connect the test harness betweenthe ECM and connectors (see
page 11-37).
Turn the ignition switch ON.
Measure voltage botween D4 (+ )terminal and D22 { - ) terminal.
connect the SCS shonconnector to servlcecheck connector.ls there approx. 5 V?
Ropair shon to body g.ound inBRN/WHT wire betwoon th6 ECMlD4) end sorvlco chock connocto?.Measure voltage be_tween D4 {+} terminaland body ground.
- R6pair open in BRN/WHT witobotwoon EcM lD4) and s6rv-ice chock connactor.- Repoir opon in BLK wiro bo-twoon 36rvi@ chock connectoaand G4Ol.
ls there approx. 5 V?
InsDoct ECU {ECM) 115 A) tuse inth6 undeFhood luse/relav box.
- Rsolaco ECU {ECM} (15 Allus€.- R6pair shon in YEL/WHT wilobotw6on ECU lEcMl 115 A)fuso and PGM-FI main rolay.
Remove the scs shortConnector from theservice check con-nector.
ls the luss OK?
NOTE:
a When there is no code stored, the MIL willstay on if the service check con-
nector is shorted.
a tf this svmotom is intermittent, check for:
- A loose ECM fuse (15A) in the under-hood tuse/relay box
- A loose No. 24 fuse (ACG) (ALT) ( 1 5A: B1 8B 1 engine, 2OA: B18C 1 en-
gine) in the under-dash fuse/relay box- An intermittent short in the BRN/WHT wire between the ECM (D4) and
the service check connector- An intermittent oDen in the BLK wire between the service check con-
nector and G4O1- An intermittent shon in the GRN/ORN wire between the ECM (A 13) and
the gauge assembly.- An intermittent short in the YELMHT wire between the ECM (D19) and
the MAP sensor- An intermittent short in the YEL/BLU wire between the ECM (D20) and
the TP sensor
o ooooo ooo ooo o loooooooo liii:$A$.Ps,l o oo ooo ooooo
o oooo ooo o o ooo I oooooooooooooooooo
D4 (+)
l"oo,o'.
D22 t-l
uu,l
'NOTE: After repair, disconnect the SCS ShortConnsctor, test drive the car, and recheckthe MIL
lor a code.
(cont'd)
(To page 1 'l -44)lTo page 1 1-44)
11-43

(From page 1 1-43)
Inspect the No. 24ACG {ALT) (lG)(15 A: 81881 engine, 2OA:818C1 enginel fuse in the under-dash fuse/relav box.
- R.pllr .hon in BLK|rEL wlr6batr.v€qr undariair luro/Fbybox lnd FGM-FI m.in .obv.- noebco lto. 24 ACG {lG) nLT)(15 A: 81881 ongin., 2OA:Bl8Cl onein.l tu!6.
ls the fuse OK?
Turn the ignition switch ON.
Disconnect the 3P connector oteach sensor one al a time:. MAP sensor. TP sensor
Rcplaoo thg lgnlor that caur6dth. llght to Oo out.Does the MIL remain ON?
Turn the ignition switch OFF.
connect the test harness.Disconnect the "D" connectorfrom th€ ECM only, not the mainwire harness (see page 11-37).
Check tor continuity betweenbody ground and D19, O2O ter-minals,
- Bapai? rhod ro body g.ound inYEL/WHT wi.e boiwoon ECM(Dl9) .nd MAP ..n3or.- R.p!k shon to body ground inYEL/BLU wire b.lwo6n ECM(O2Ol .nd TP 3on!or.
Reconnect all tho sensor con-necrors,Reconnect the "D" connector torhe ECM.
Turn the ignition switch ON.
{To page 11-45}
System
Control Module (ECMI (cont'dl
PGM-FI
Engine
Dt9I
I oooooooooo ooo I oooooooo I omoool o oooooooooo | |I ooooooooooooo I oooooooo 1o('oe(lo I ooooooooooo | |-lD2O I
\-.J
Continuity?
(From page 11-43)
Disconnect "A" con-nector from the ECM.
Subrtltute r knowngood ECM.nd rochock. ll lymptom/indics-tlon g@a rw!y, rephco tho origi-n.l ECM.
ls the MIL ON?
Ropair short to bodygiound in GRN/ORNwir6 botwoon tho ECMlA131 6nd MlL.
11-44

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
Knock Sensor (KS) tB18C1 enginel
ml- nl: The Malfunction Indicator Lamp (MlL) indicates Diagnostic Troubte Code (DTC) 23: A probtem inthe Knock Sensor (KS) circuit.
a6l--fzt.i--1/.---r+\
ware sido
o ooooo ooo ooo o looooooooo oooo ooo oo ooo I oooo oooo
11-74
- The MIL h6s boon r6port6don.- With th6 SCS ahort connec-tor connoctod (soe pago11-341, codo 23 is in-dicrtod.
Oo the ECM Reset Proceduro (seepage 11-35).
Start the engine. Hold the engineg!-3,Opq rpm with no load {A/T in
Lryl orlPlposirion, M/T in neurra until the radiator fan comes on,then let it idle.
Hold the engine at 3,0O0-4,000rpm for 10 seconds.Intomittor failure, ay5-t.m is OK at this tim6(teat drivo mav bonec€saary,.Chock tor Door connec-tion3 or loo3o wlaos etC222 {locatod 6r ghrshock tow6r), Cl33(KSl and ECM.Turn the ignition swirch OFF.
Connect the test harness to themain wire harness only, not to theECM (see page 1 1-37).
Check for continuity between D3terminal and body ground.
Ropdr short in RED/BLUwiro b€tweon ECM {D3land ths Ks.
(To page 11-75)

ldle Control System
Fast ldle Thermo Valve
DEscliptlon
To prevent erratic running when the engine is warming
up, it is n€cessary to raise the idle speed. The fast idle
thermo valve is controlled by a thermowax plunger, When
the engine is cold. the engine coolant su.rounding the
thermowax contracts the plunger, allowing additional air
to be bypassed into the intake manifold so that the en-
gine idlss taster. When the engine reaches operating tem-
peratur€, the valve closss, reducing the amount of air
bypassing into the manifold.
FAST IDLE THERMOVALVE
AIN EYPASS VALVE
Inspaction
NOTE: The tast idle thermo valve is factory adiustsd;
it should not be disassombl€d.
1. Remove the intake air duct from the throttlg body.
2. Stan the engine.
3. Put your finger over ths lower port in throttle body
and make sure that there is 8ir flow with tho engine
cold (engine coolant temperatute below 86oF,
300c).
a lf not,
retest.
leplace the fast idle thermo valvs and
4.
o-Rr{GsReplace
llo kgf.m, 7 lbt.trl
Start the engine. Hold the sngine at 3.0OO rpm with
no load (A/T in I or @ position, M/T in neutral]
until the radiator fan comes on, then let it idl6.
Check thst valve is completely closed. lt not, air suc-
tion can be telt at the lower Don in the throttle body,
a It any suction is felt, the valve is leaking Check
engine coolant level and for air in tho engine
coolant system (see section 1O). ll OK, rsplace
the fast idle thermo valve and rechock.
11-94

- ldle Speed Setting
Inspoction/Adiustment
NOTE:
a When the idle speed set, check the following items:
- The MIL has not been reported on.- lgnition timing- Spark plugs- Air cleaner- PCV svstem
a (Canada) Pullthe parking brake lever up. Stan the en-
gine, then check that the headlights are off.
1 Start the engine. Hold the engine at 3,000 rpm with
no load (A/T in S or @ position, M/T in neutral)
until the radiator tan comes on, then let it idle.
2. Connect a tachometer.
3. Disconnect the 2P connectot trom the ldle Air Con-
trol {lAC) valve.
Start the engine with the sccelerator pedal slightly
depressed. Stabilize the rpm at 1 ,OOO, then slowly
release the pedal until the engine idles.
Check idling in no-load conditions: headlights, blower
fan, rear defogger, radiator fan, and ai. conditioner
are not operatrng.
ldl€ spood should bo;
81881 ongino:
MlT48O ! 50 rym
An48O I 50 rpm
lin@or@oosition)
818C7 engine:48O ! 50 rym
Adjust the idle speed, if necessary, by turnmg the
idle adiusting screw.
NOTE: After adiust the idle speed in this step, check
the ignition timing (see section 231.
lf it is out ot spec. go back to step 4.
4.
e
Turn the ignition switch OFF.
Reconnect the 2P connector on the IAC valve, then
remove the BACK UP (7.5 A) fuse in the under-hood
tuse/relav box for 1O seconds to reset the ECM.
Restart 8nd idle the engine with no-load conditions
for one minute, then check the idle speed.
NOTE: (Canada) Pull the parking brake lever up.
Start the engine, then check that the headlights ate
off.
ldlo speed should be;
81881 ongino:
MTf75O ! 50 rpm
AIT75O t 50 rpm
(in[]or@positionl
818C1 engine: 750 1 50 rpm
(cont'd)
11-95

ldle Control System
ldle Speed Setting (cont'd)
10.
9. ldle the engine for one minute with headlights {Low}
ON and check the idle sDeed.
ldla sp6od should bo;
81881 engine:
M/T750 i 50 rpm
An75O t 50 rpm
{in $ or p] positionl
818C1 engine: 75O 1 50 rpm
Turn the headlights off.
ldle the engine for one minute with heater tan switch
at Hl and air conditioner on, then check the idle
speeo.
ldls spood should bo;
81881 ongino:
M/T82O 1 50 rpm
AN840 1 50 rpm(in [N] or lll position)
818C1 engino: 85O t 50 nm
NOTE: lf the idle speed is not within specitication,
see System Troubleshooting Guide on page 1 1-78.
11-96