1994 HONDA INTEGRA emission

c510
NOTE: a Ditferent wiros with tho samo color hava been given a numb€r sutfix to distinguish them {for example
YEL/BLKI and YEL/BLK, are not th€ same).
O: R€lated to Fuel and Emissions Systom.
a - Connoctor ol malo tarminals: Vi6w from terminal side- Connector ol f6msl€ tarminals: Vi€w from wire sid€
11-31

Troubleshooting
Troubleshooting Guide
NOTE: Across each row in the chart. the systems that could be sources of a symptom are ranked in the order they should
be inspected staning with O. Find the symptom in the left column, read across to the most likely source. then refer
to the page listed at the top of that column. lf inspection shows the system is OK, try the next mosr likely system O, etc,
* lf codes other then those listed above are indicated, count the number of blinks again. It the MIL is in fact blinking
^ these codes, replace the ECM.
qy, lf the MIL is on while the engine is running. connect the SCS shon connector to the service check connector. It no
code is displayed {MlL stays on steady), the back-up system is in operation.
Substitute a known-good ECM and recheck. lf the indication goes away, replace the original ECM.
USA:
MALFUNCTION
INDICATOR
LAMP {MIL)
CANADA: ----l CHECK-ltGl- ENGTNE- | - LTGHT
- { -1t-
* * *: 818C1 engine
1-32
SYMPTOM
PGM.FI
ENGINECONTROLMOOULE
HEATEOOXYGENSENSOR
MANIFOLOAESOLUTEPRESSURESENSOR
TOP DEAD CINTTR/CRANKSHAFTPOSTT|ON/CYLINDERPOSITION SENSOR
ENGINECOOLANTTEMPfRA.TURTSENSOR
THROTTTEPOStTtONSENSOR
INfAKE AIRTEMP€RA.TUREsar,rs0R
BARO.METRICPRESSURESENSOR
IGNITIONOUTPUTSIGNAL
vEHtct-ESPfEDSENSOR
11.4246, 47,5011-56l1-581l-6011-6211-641t-661r-68
MALFUNCTION INOICATORLAMP (MIU" TURNS ON1 lor:t:]:lrmr:- i;:i'-tK3t-16l-16l'-\-16l/-----\
-r:+r-
-{"Pr:-o_-16l-.z-\r6t/_-\
MALFUNCTION INOICATORLAMP (MIL)'' BLINKS:O. or-8.-D:o.:@.
o, O'l3l/__-\.E-o.:O: or tr]--i !l/ -i-\| 7 t-/__-\
--l-l-l r0 I/----\| 13 |z_---\
\.--r--l
I r5 t-/.---\-t 17 t-/-]-\
ENGINE WON'T STAffTo@@
DIFFICULT TO STARTENGIN€ WHEN COLO@@(9)o
IRREGULARIDLING
WHEN COTDFAST IDLEouT 0f sPtc@@
ROUGH IDLE@o
RPM TOOHIGH@@
RPM TOOLOW@
FREOUENTSTALLING
WHILE@@
AFTER@
POOnPERFOEM.ANCE
MISFIRE ORROUGHRUNNING@@@
FAITSEMISSIONTEST@@@
Loss 0FPOWER@@@

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

ldle Gontrol System
System Troubleshooting Guide
NOTE:
a Acrosa each row in the chan, the sub-systems that could be sources of a symptom are ranked in the order they should
be inspected, starting with O. Find the symptom in the left column, read across to the most likely source, then reler
to the page listsd at ths top ot that column. It inspection showa the system is OK, try the next system @, etc.
a lf the idle speed is out of sp€cification and th€ Malfunction Indicator Lamp {MlL) does not blink Diagnostic Trouble
Code (DTC) 14, 9o to inspection describ€d on pags 1 1-81.
PAGE
SYMPTOM
IDTIOJUSTIiSCREW
IDLE AIRc0NTROt-
AIRcoN0fTtoNtitcSIGNAL
ALTER.NAION FNSIGNAL
AUTOMATICIRAI{SA(LEGtARP0sm0 stGIAt
ERAK€swrTcHSIGNAL
STARTERswtTcHSIGNAT
POWERSTEERII'IGPffESSUREswncHSIGNAL
FAST IOLETHERMO
HOSESANOCONNEC.TIONS
11-9511-4211-841 1-8611-8811-9011-92I 1-9311-94
DIFFICULT TO STARTENGINE WHEN COLD@o
WHEN COLD FAST IDLE OUT OFSPEC l1,0OO- 2,0OO rpm|o@o
ROUGH IDLEo
WHEN WARM RPM TOO HIGHooo
WHEN
TOO LOW
ldl6 3p6od b b€lowspecitisd rpm (no loadl@o
ldla 5p66d doos nolincraas€ alter initialo
On mod6l3 with auto-matic transmBsion, thsidlo sp€ed drops in 963ro
ldl6 sp€eds drops when8ir condilioner in ONoo
ldls spo6d drops when6ts6iing wh66l i6 turninC@o
ldla spoed lluctust63with alactrical loado
FREOUENTSTALLING
WHILE WARMING UP@o
AFTER WARMING UPo@
FAILS EMISSION TESTo
11-78
.,Hilffirl|,

lntake Air System
Throttle Body
Description
The throttle body is ot the single-barrel side-draft 1ype.
The lower portion of the throttle valve is heated by en-gine coolant from the cylinder head. The idle adjusting
screw which increases/dec.eases bvDass air and the
Evaporative Emission (EVAP) Control Canister port are
located on the top of the throttle body.
IOLE AOJUSTING
THROTTLESTOP SCREW(Non-adiustsb16l
11-120
Insoection
CAUTION: Do not adiust the thlottle stop screw. lt ispreset at the lactory.
1. Start the engine. Hold the engine at 3,OOO rpm with
no load (A/T in S or E position, M/T in neutral) until
the radiator fan comes on, then let it idle.
2. Disconnect the vacuum hose (to the EVAP control
canister) from the top of the throttle body; connect
a vacuum, gauge to the throttle body.
VACUUM PUMPGAUGEA973X-O41-XXXXX
5.
3. Allow the engine to idle and check that the gauge
indicates no vacuum.
a li there is vacuum, check the throttle cable (see
page 1 1-'l 18, 119).
Check that vacuum is indicated on the gauge when
the throttle is opened slightly from idle.
a lf the gauge indicates no vacuum, check the throt-
tle body port. lf the throttle body port is clogged.
clean it with carburetor cleaner.
Stop the engine and check that the throttle cable
operates smoothly without binding or sticking.
a lf there are any abnormalities in the above steps,
check for:
- Excessive wear or Dlav in the throttle valve shaft.
Sticky or binding throttle lever at full close po-
srtron.
Clearance between throttle stop screw and throt-
tle lever at tull close Dosition.

Emission Control System
System Troubleshooting Guide
NOTE: Across each row in the chart, the sub-systems that could be sources of a symptom are lanked in the ord€r they
should be inspected starting with O. Find the symptom in the lett column, read across to the most likely source, then
reJer to the page list€d at the top of that column. lf inspection shows the system is OK, try the next most likely system
@, etc.
PAGE
SYMPTOM
SUB.SYSTEMTHREE WAY
CATALYTIC
CONVERTER
POSITIVE
CRANKCASE
VENTILATION
SYSTEM
EVAPORATIVE
EMtSSTON
CONTROLS
11-132, 1331 1- 13411tJo
ROUGH IDLEo
POOR PERFORMANCE
FAILS
EMISStON
TEST
o@
LOSS OF
POWERo
11-129

Emission Control System
SystemDescription
The emission control system includes a Three Way Cata-
lytic Convener (TWC), Positive Crankcase Ventilation(PCV) system and Evaporstive Emission {EVAP) Contfol
syst€m. The emission control system is designed to meet
federsl and stats emission standards.
Tailpipe Emission
Inspection
f!fifil oo nor amoro ou]rng rnr! Foacqurr. ^!op
any open flame away from yout wotk atca.
Start the engine. Hold the engine at 3,OOO rpm with
no load (A/T in @ or@ position, M/T in neutral) until
the radiator fan comes on, then let it idle,
Connect a tachometer.
Check and adiust the idle speed, if necessary (sss
page 1 1-95).
Warm up and calibrate the CO meter according to
the meter manutacturer's inst.uctions.
Check idle CO with the headlights, hester blower,
rear window defogger, cooling fan, and air condition-
er otf.
NOTE: (Canada) Pull the parking br8ke lever up.
Stan the engine, then check that the headlights are
off.
CO meter should indicate 0.1 maximum.
11-130

Emission Control System
Three Way Catalytic Converter (TWC) (cont'dl
Inspection
lf sxcessive oxhaust system back-pressure is suspected. remove the TWC trom the car and make a visual check for plug-
ging, melting or cracking of ths catalyst. Replace the TWC if any of the visible area is damaged or plugged.
81881 ongino:
TI{REE WAYCATALYTICCONVERTER {TWCIRemovsl/installation, see section 9
Inspect housing for cracks orother damage.Inspect element tor cloggingby looking through the inside.
HEAT SHIELD
11-132
T SHIELO