1994 HONDA INTEGRA main relay

@ ne-oving the radiator cap while the engine
is hot can cause the engine coolant to splay out, seri-
ously scalding you. Always let the engine and radiatol
cool down betore removing the radiator cap.
CAUTION: When poudng engine coolant, be sure to shut
the relay box lid and not to let coolant spill on the elec-
tlical pans or the paint. ll any coolant spills, rinse it otf
immediately.
1. Slide the heater temperature control lever to maxi-
mum heat.
Make sure the engine and radiator are cool to the
touch.
2. Remove the radiator cao.
3. Loosen the drain plug on the bottom of the radiator,
and remove the drain bolt from the enoine block. Let
the coolant drain out.
ENGINE DRAIN BOLT78 N.m {8,O kgt.m, 58 lbt.ftlApply liquid gasker tobolt thread when installing.WASHERReplace.
5.
Remove the reservoir from its holder by pulling it
straight up. Drain the coolant, then put the reservoir
back in its holder.
When the coolant stops draining, apply liquid gasket
to the drain bolt threads, then reinstallthe bolt with
a new washer. Tighten it securely
6. Tighten the radiator drain plug securely.
7. Mix the recommended antifreeze/coolant with an
equal amount of water in a clean container.
NOTE:
. Use only HONDA-RECOMMENOED antifreeze/
coolant.
a For best corrosion protection, the engine coolant
concentrations must be maintained year-round at
50% MINIMUM. Coolant concentrations less than
50% may not provide sufficient protection
against corrosion or freezing.
CAUTION:
a Do not mix ditterent blands ot anti-freeze/
coolants.
a Do not use additional rust inhibitois or anti-rust
products; they may not bs compatibl€ with the
recommgndsd engins coolant.
Engin€ Coolant Retill Capacity: including reservoir
{0.6 t (0.6 US qt, 0.5 lmp qt)).
81881 engine:
MlTt 4.4 | (4.6 US qt, 3.9 lmp qr)
Afft 4.7 [ (5.O US qt,4.1 lmp qt]
Bl8Cl engine:
Mnt 4.7 | (5.0 US qt.4.1 lmp qt)
8. Pour coolant into the radiator up to the base of the
filler neck.
9. Loosen the bleed bolt on top of the engine. Tighten
it again when coolant comes out in a steady stream
with no bubbles.
BLEED BOLT
1O. Refill the radiator to the base of the tiller neck. Put
the cap on the radiator. and tighten it only to the tirst
stop, Stan the engine and let it run until it warms
up (the radiator cooling fan comes on at leasttwice).
11. Turn oft the engine. Check the level in the radiator,
and add coolant it needed. Install the radiator caD,
and tighten it fully.
'1 2. Fill thereservoirto the MAX mark. lnstallthe reser-
voir cap.
9.8 N.m (1.O kgl.m, 7.2 lbf.ftl
Engine Coolant Refilling and Bleeding
10-5

AIR CLEAI{ER IACL)Replacoment,11-117
THROTTLE BODY (T8I
Inspsction, page 1 1-120Disassembfy, page 11'122THROTTLE CABLEInsDection/Adjustment, pages 1 l-'l 18, 1 19
Inslallation, pages 1 1-1 18, 119
POSITIVE CRA KCASEvEt{TtLATtOt{ (PcVl VALVEInspection, psgo 1 l-134
INTAKEAIREYPASS IIABIco TnoLSOLENOIDVALVE (B18Cl .ngino onlylTroubl6shooting,page 1 1-124
INTAKEAIRBYPASS (IABI
co TROLOIAPHRAGM{Bl8C1 ongino onlylTroubleshooting,page 11-124
I
RESONATOR
ENGI]TE CONTROL MODULE {ECM)Selt-diagnostic Procedures, page 1 1-34Troubfeshooting, page 1 1 -42
MAIN RELAYRelay Testing, page 1 1- 111Troubleshooting, pag€ 1 1-112SERVICE CHECX CONNECTOR (2PI
56ll.diagnostic Procedures, page'l 1-34
11-5

System Description
System Connectors [Dash and Floor]
PGM-FI MAINRELAY
C1I44 UNDEN-OASHFUSE/REALYBOX
ENGINECOMPARTMENTWIRE
DASHBOARO WIREHARNESS
MAINWIREHARI{ESS
REARWIREHARNESS
11-24

System Description
System Connectors [Dash and Floor] {cont'd}
UNDER-DASHFUSE/RELAYBOX
DASHBOARDHARNESS
MAINWIREHARNESS
11-26

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

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 1l-44)
Measure voltage between 426
{- ) and the following: B'1 (+ } andA25 {+ t.
- Ropsir opon in YEL/BLK wirobotwoon ECM (425, 81l andPGM-FI m6in relay.- Chock PGM-FI main rclay andwiring connectors at PIGM-FImain.olay (soe psg6 11-1121.
ls there battery voltage?
Measure voltage between bodyground and the tollowing termi-nals individually: A23. A24, A26,42.
- noprir opon in BLK wit. b6-twson ECM 1A23, A24l andG'101 {locatod al th6.mostathousingl.Repair opon in BRN/BLK witebotweon ECM (A26, B2l andGl0r.
ls there less then 1.0 V?
Substitut6 r known{ood ECM
and r6chock. lf symptom/indica-tion goos away, roplaco tho origi-nal ECM.
BATTERYVOLTAGET
ooooooooooo
oooooooooooooooooooooo
ooooooooooo
oooooooo
ooooooo
L€ss than 1.0 V?
11-45

System Description
The idle speed ot lhe engine is controlled by the ldle Air Control {lAC) Valve.
The valve changes the amount ot air bypassing into the intake manifold in response to electric current controlled by the
ECM. When the IAC Valve is activated, the valve opens to maintain the proper idle speed.
#l' ----rTo FGM-FIMAINRELAY
VARIOUSSENSORS
IAC VALVE
FASTIDLETHERMOVALVE
INTAKE MAI{IFOLD
(cont'd)
BLK
r
11-79