1994 HONDA INTEGRA fan 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

System Description
Electrical Connections
PGM.FI MAII{ RELAY
- rc2l L
IllLii |
ril.i--r {a/Tl
To BAOIATOR FAt!RETAY, CONDENSERFAI{ RELAY
To A/C SWITCH
FUEL INJ€CTORS
@
DATALIIIKco t{EcToR
fUELPUMP
A/C CLUTCH RELAY
FUSES
O BATTERY I1OO AI*
@ oPTroN t50 alr
o rG {50 A).
@ sroP. HoBN {2O Al*
@ BACK UP (7.5 Al*
@ No. 3 INTERIOR LIGHT {7.5 A)
O Ecu (EcMt (1s A)'
@) No. 24 ACG (ALTI 0Gl{15 A: 81881 sngin6,2OA:818C1 6n9ine)
@ No. 15 BAcK-uP LlcHTs llo Al
@ No. 13 REAR DEFROSTER RELAYHEATER MOTOR RELAYCOOLING FAN MOTOR RELAY I7.5 A}
O No. l8 STARTER SIGNAL 17.5 A)
*: UNDER-HOOD FUSE/RELAY BOX
11-12
A/T GEAR

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

Heater
lflustrated Index ............. .........21-2
Heater Door Positions .........,..,. 21-3
Circuit Diagram ....................... 21-6
Troubleshooting
Symptom Chart ............. ......21-8
Flowcharts
Blower Motor Speed ............................... 21 -9
Bfower Motor .........,..,,,,,.. 21-11
Mode Control Moto. ............ ................... 21 -14
Recircufation Control Motor ......,...,.,,,.,.... 21 -17
Heater Control Panel Input/
Output Signals ..............21-19
Blower Unit
Repfacoment ....................... 21-20
Overhaul .......21-21
+Heater Unit
Repfacement ....................... 21-22
Overhaul .......21-24
Def roster Door Adjustment ...,............. ......,, 21 -25
Heatel Control Panel
Repfacoment ....................... 21-25
Overhaul .......21-26
Heater Valve Cable
Adjustment ...21-27
Air Mix Control Cable
Adjustment ... 21-27
Mode Control Motol
Test .............. ..................... 21-2e
Repfacement ..,..............,,,,.. 21-28
Recirculation Control Motor
Test .............. ..................... 21-29
Repfacement ....................... 21-29
Relay
Test .............. ..................... 21-30
Heater Fan Switch
Test .............. ..................... 21-30
Mode Control Switch
Test .............. ..................... 21-31
Recilculation Control Switch
Test .............. ..................... 21 -31
*: Read SRS precautions before working in this area.

Relay
There should be continuity b€tween the A and C termi-
nals when Dower and ground are connected to the B and
D terminals.
There should be no continuity when power is discon-
nected.
Heater Fan Switch
Check for continuitv bstween the terminals according to
the table below.
Terminal
PositionADBE
OFF
,lo--o
o--o
3o--o
4-o
rl
I
I
r?
21-30

Wiring/Connector Locations
A/C DIODECONNECTOR(Loc.ted .bovo tho.ight kick p.n.ll
RADIA'OR FAN RELAY{Localed in the undel-hood fu3o/reltY box)
A/CTHERMOSTAT CONDENSERFANCONNECTOR CONNECTOR
MAIN WIRE HARNESS
A/C WIRE HARNESSCONNECTOR
RADIATOR FANCONNECTOR
A/C WIRE HARNESS
COMPRESSOR CLUTCHCONNECTORA/C PR€SSURE SWTTCHCONNECTOR
22-4

Troubleshooting
Reference Ghart
. Any abnormality must be correctsd before continuing the test.. Because of the precise measurgments needed, use a multimeter when testing.
Before performing any troubleshooting procedures check:. Fus€s .r No. 35120 A), *1 No. 33 (20 A), ), No. 13(7.5A). Grounds No. G401, G201, G'151, G101. Cleanliness and tightness of all connectors*1: In the under-hood fuse/relay box*2: In the under-dash fuse/relay box
SYMPTOMREMEDY
Radiator fan does not run 8t all.Perform the procedures in the flowchan (see page 22-8).
Condenser fan does not run at all.Perform the procedures in the flowchart (see page 22-10).
Both fans (radiator and condenser) do not
run for engine cooling, but they both run
with the Ay'C on.
Perform the procedures in the flowchan (see page 22-12).
Eoth fans do not run at all.Perform the procedures in the flowchart (see page 22-13).
Compressor clutch does not engage.Perform the procedures in the flowchart (see page 22-14).
Ay'C system does not come on
{compressor and both fans}.Perform the procedures in the flowchart (see page 22-16).
22-7

Troubleshooting
Radiator Fan
Redi.to. fan doo3 not run at all.
check rhe No. 33 {20 A) fuse inthe under-hood luse/relay box.
Remove the radiator lan r€layfrom the under-hood Iuse/relaybox and test it (see page 22-19).
Raplaca tha radiator tln rahy.
Measure the voltage between theNo. 3 terminal (+) and bodyground {-}.
ls therg battery voltag€?
Connect the No. 1 and No. 3 ter-minals with a jumper wire.
Does the radiator Ian run?
Chock for continuity in the BLK./RED wire between the No. 1 ter-minal and the radiator fan.
R.p.ir opdr in th. 8LK/RED wir.batwaon th. unda.-hood fut./ralay box rnd tha radirtor f.n.
Check for continuity in th€ BLKwire between the radiator {anand body ground.
Ch.ck to..n op.n in th. BLKwirc batwaan th. rldirtor hnlnd body ground, lf tha wita i!OK, chack tor poor gtound rtG2ol lnd GiOl.
Rephco tho radi.tor frn motor.
To p3ge 22-9
22-A