1994 HONDA INTEGRA indicator

Troubleshooting
Self-diagnostic Procedures
When the Malfunction Indicator Lamp {MlL) has been reported on, do the following:
'1. Connect the SCS short connecto. to Service Check Connector as shown. (The 2P Service Check Connector is
located under the dash on the passenger side of the car.) Turn the ignition switch on.
DATA LII{KCONNECTOR (3PI
NOTE:Do not attachjumper wire.
2. Note the Diagnostic Trouble Code (DTC): The MIL indicates I code by the length 8nd numbsr ot blinks. The MIL
can indicate multiple component problems by blinking separate codes, one after another. Codes 1 through Igre
indicated by individual shon blinks. Codes 1O through 43 are indicated by a series of long and shon blinks. Th€
number of long blinks equals the first digit, the number ot short blinks equals the second digit. Sometimes the
firsr blink is difficult to see; always count the blinks at least twice to verify the code.
MALFUNCTIOI{INDICATORLAMP
CANADA:CHECKENGINELIGHTIMIL}
Sgprrate Prcbaomr:shT
-n-----n- =n- = s.o DTc 1
+!+1].TL;I!!=- = s.. Drc 3-L ,JU '" " " = Sce DTC 13
Long .hon
Multiplr Probl.ln.:
J-l_tx-TL-n-ffu-r- = S€. DTC 1 lnd 3-J.rrU-L-r]tltlr'l- __-tnrua = Sce DTC 3 and 4Jll-lrl-t-----Tt/'tnj]_ = S.. DTC 3 lnd 14
11-34

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

How to Read Flowcharts
A flowchrrt is dasigned to be us€d fiom start to final repair. lt's like a map showing you the shortest distanco. But be-
ware: if you go off tho "map" anywhere but a "stop" symbol, you can easily get lost
l6rffil Desclibas the conditions or situation to start a troubleshooting flowchart.(bold tyDo)
|TeTiONl Asks you to do something; pedorm a test, set up a condition etc'
<:6Eei6io-fr\> Asks you about the result of an action, then sends you in the appropriste troubleshooting direction.
I-SJTFI The snd of a series ot actions and decisions, describes I tinal repair action and aomotimea diracts
(bold typel you to 8n garlier part of the tlowchart to confirm your repair'
NOTE:
a Tha tarm ,,lntormittgnt Failure" is used in these chans. lt simply means a system may have had a failur6, but it chocks
out OK !t this time. lf th6 Msltunction Indicator Lamp (MlL) on ihe dash does not come on, check for poor connections
or loose wires at all connectors rolated to the cilcuit that you are troubleshooting (see illustration b6low).
a Most ot tho troublashooting flowchans have you reset the Engine Control Module (ECM) and try to duplicate the Disg-
nostic Troubls Cod6 (DTC). lf the problem is intermittent and you c8n't duplicat€ the cod6, do not continus through
the flowchart, To do so will only rosult in confusion and, possibly, a ne€dlessly replaced ECM
a ,,opon,'and ,,short,, are common electrical terms. An open is a break in a wir6 or at a conn€ction. A short is an
accidontal connaction ot a wir€ to ground or to another wire. In simple electronics, this usually means som€thing won't
work at all. In complex electronics (like ECM's), this can sometimes mean something wolks, but not the way it's sup-
poSad to,
a il th6 olectricsl readings are not as specified when using the test harness, check the test harness connoctions bsfore
procooding.
LOOSE
11-39

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
Engine Control Module (ECM)
lB18B1 ongino onlyl
The Malfunction Indicator Lamp(MlL) n6v6. com6s on lovon follwo socondal aftor ignition istumed on.
lurn the ignition switch ON.
Inspect No. 15 {BACK-UP LIGHT}l1O A) luse in the underdashtuse/relay box.ls the low oil pressure light on?
- R€placo No. 'l5
IBACK-UP LIGHT)llo Al fuso.- Ropair short inYEL wiro botwoonNo. 15 (BACK-UP
LIGHT) {10 A) fusoano gauge 6$om-blv.
Turn lhe ignition switch OFF.
ls the fuse OK?
Connecl the test harness betweenthe ECM and connectors (seepag€ 11-37).Repair opon in YEL wiio botw6onNo.'15 IBACK-UP LIGHTI 110 A)luso and gaug6 assombly.
Turn the ignition switch ON.
- RsDlaco tho MIL bulb.- Ropair opon in GRN/ORN wi.ebetwoen ECM {A13} andgaug€ a$6mbly.
ls the MIL on?
Measure voltage between body
Oround and the tollowing termi-nafs individuallv: 423, 424.
Ropah op6n in BLK wirolsl bo-tw6en ECM and GlOl llocatod atthormostat housing) that hadmoro than 1.0 V.
ls there less than 1.O V?
Substituto a known-good ECMand rochgck, lf symptom/indica-tion go€s away, roplaco tho origi-nal ECM.
NOTE: lf this svmptom is intermittent. check for a loose fuse No. 15 (BACK
UP LIGHT, 1OA) in the under-dash Juse/relay box, a poor connection at ECM
terminal A13, or an intermittent open in the GRN/ORN wire between the ECM(A13) and the gauge assembly.
I A13
I| | o oooo oooooooo I oooo oooo I ooooool ooooooooooo I
G 10'l
11-42

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

mll )ffltl The Malfunction Indicator Lamp (MlL) indicates Diagnostic Trouble Code (DTCI 41: A problem in
Y- -:- the Heated Oxygen Sensor {HO2S) Heater circuit.
-.----r- \- l-l
tt(gt- -t tt I-r---7r
DIGITAL MULTIMETEBCommorcially availablo orKS-AHM-32-OO3
- Th6 MIL has boen roponod on.- With the SCS rhort connoc-to. connociod (aoe pago
11-341. codo 41 is indic.tod.
Do the ECM Reset Procedure {seepage 11-351.
Intoamittont tdl||.g, ryr-t m i3 OK at thi! timo(tost driv6 lnay bg ns-cearatYl.Chock tor poor conn6c-tions or looro wires atC223 llocatod at rightshod( row..l, C3O5 {lo-cated 6t loft ahock low-or), C424, C113(HO2S) and ECM.
ls the MIL on and does it indi-cste code 41?
Turn the ignition switch OFF.
Measurc tasistance betwgen ter-minals 3 snd 4 on the HO2S.
ls thero 1O-4O 0?
t€rminal side
(To page 1 1-481
(cont'd)

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