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
Relay and Control Unit Locations
Dashboard and Door
CRUISE CONTROL UNIT
PGM-FIMAIN RELAY
STARTER CUT RELAY IMIT)
I wir. colo]s: BLKMHT, BLU/BLK II BLKMHT ANd BLK/RED I
Wirs colors:WHT,GBN/BLK,GRN 6nd BLK
MOONROOF RELAYREAR wlNDOW DEFOGGERFELAY
I Wiro colo6: II BLKA'EL, BLK/GBN, I
I BLUffEL 8nd BLK^^THT I
POWER WINDOWRELAY
IIORN RELAY
J wi.o color3: WHT/GRN, BLx,l
I BLU/GBN, and BLU/RED I
INTEGRATEOCONTROL UNIT
TURN SIGI{AL/HAZARDRELAY UNDEB-OASHFUSE/RELAY 8OX
23-8
Connector ldentification and Wire Harness Routing
Msin Wiie Harness (Left branch)
Connector or
Terminal
Numbel ot
CavitiesLocationConnects toNotes
c411
c412
c413
c414
c415
c416
c4'17
c418
c419
c420
c42'l
c423
c424
c425
c426
c427
c42A
c429
c430
c431
c43l
c432
c433
c434
c435
c436
c437
c438
c439
c440
c44'l
c442
c443
c444
c445
c446
c447
c448
c449
26
10
20
20
14
8
4
I
14
20
22
't4
4
2
10
4
7
4
o
7
I
7
22
6
4
7
4
15
to
Center floor
Center floor
Center floor
Under left side ot dash
Behind left kick panel
Behind left kick panel
Behind left kick panel
Behind left kick panel
Behind left kick panel
Behind left kick panel
Behind left kick panel
Behind left kick panel
Under left side of dash
Under left side of dash
Under lett side of dash
Under left side ot dash
Under lett side of dash
Under lett side of dash
Under lett side of dash
Under lett side of dash
Under lett side ot dash
Under left side of dash
Under left side ol dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Under left side of dash
Behind dashboard lower cover
Behind dashboard lower cover
Behind dashboard lower cover
Under left side of dash
Under left side of dash
Under left side of dash
Under lett side of dash
Under left side of dash
Behind under-dash fuse/relay box
Under left side ot dash
Behind dashboard lower cover
Behind dashboard lower cover
A/T gear position console light
Shift lock solenoid
A/T gear position switch
Interlock control unit
Daytime running lights control unit
Daytime running lights control unil
Cruise control unit
Junction connector
Transmission control module
(TCM)
Transmission controi module
{TCM)
Rear wire harness (C501)
Rear wire harness {C502)
Engine compartment wire harness
(c301)
Engine compartment wire harness
(c302)
Roof wire harness (C663)
Security system (Option)
SRS main harness (C802)
Clutch interlock switch
Clutch switch (Cruise control)
Dashboard wire harness (C552)
Brake switch (Without cruise
control)
Brake switch (With cruise control)
lgnition switch
Security system (Option)
Combination light switch
Combination light switch
Combination light switch
Combination light switch
Under-dash fuse/relay box {C9131
Under-dash fuse/relay box {C9161
Underdash tuse/relay box (C9'l 7l
Security system (Option)
Security system {Option)
PGM-FI main relay
Starter cut relay
Rear window defoqger relay
Integrated cont.ol unit
Security system {Option)
Horn relay
Dashboard wire harness (C553)
Afi
AiT
Afi
Afi
Canada
Canada
Arf
An
Canada
Canada
M/T
M/T
Atr
Canada
Canada
M/T
Canada
G401Behind left kick panelBody ground, via main wire
harness
23-26
Starting System
Gomponent Location Index
A/T GEAR POSITION SWITCHTest, page 23-136Replacement, page 23-137
BATest, page 23-66
STARTER CUT RELAY {M/T}Test, page 23,68
CLUTCH INTERLOCK SWITCH (M/T}Test, page 23-78Switch Adiustment. section 12
Test, page 23-76Solenoid Test, page 23 78Repfacement, page 23 79Overhaul, pages 23-8OReassembly, page 23,85
23-73
5. Check lor 8n op€n in the BLKMHT wire circuit be-
tween the staner and ignition switch, and con-
nectors.
6. Check the ignition switch (see page 23-70).
7, On cars with automatic transmission, check the A/Tgear position switch (neutral position switchl and
connector. On cars with manualtransmission, check
the staner cut relay, clutch interlock switch, and
connectors.
NOTE: Check the No. 39 (5O A) fuse in the under-hood
fuse/relay box for the starter cut relay.
Check tor Woar and Damago:
The starter should crank the engine smoothly and stead-
ily. lf th€ startsr engages, but cranks the engine errati-
cally, remove it. Inspect the starter, drive gear, and
flywheel ring gesr for damage.
a Check the drive gear overunning clutch for binding
or slipping when the armature is rotated with the drivegear held. Replace the gesrs if damaged.
Check Cranking Voltago 8nd Current Draw:
Cranking voltage should be no less than 8.O volts.
Current draw should be no more than 360 amperes.
lf cranking voltag€ is too low, or current draw too high,
check for:
a Fully charged battery
a Open circuit in starter armature commutatot segments
a Starter armature dragging
a Shoned armature winding
a Excessive drag in engine
Chack Cranking rpm:
Engine spsod during cranking should be above 1O0 rpm.
lf spe6d is too low, ch€ck for:
a Loose battsry or starter teminals
a Excessively worn starter brushes
a Open circuit in commutator segments
a Dirty or damaged helical spline or drive gear
a Defective drive gear overrunning clutch
Chock StErtor Disongagomoni:
Press the clutch pedal allth€ way in (M/T), turn the ioni-
tion switch to "lll" and rolease to "11".
The starter drive gear should disengage from the tlywheel
ring gear. When you rolease the key.
lf the drive gear hangs up on th€ flywheel ring gear, check
for:
a Solenoid plunger and switch malfunction
a Dirty drive gear assembly or damaged overrunning
clutch
23-77
Bulb Check System
No. Tsrminal
(blake system lightl
Test condition
Lights-on Romind6r Systom:
Wire/
No, ToiminalT6Et condition
Side Markol Light Flashar System:
Wiro/
No. TerminalTest condition
Tost: Desirod resuhPossibls caus6 it result is not obtainod
Tost: Dositod rosuhPossibl6 caus6 if rosuh is not obtainod
Tast: Desired rosultPo$ible cause if result is not obtained
IM
lgnition switch at
STARTCheck lor voltage to ground:
There should be battery voltage.
Blown No. 18 {7.5 Al fuse in theunder-dash fuse/relay box
Faulty clutch int€rlock switch or
starter cut relay {M/T}Faulty neutral position switch (A/T)
An open in the wire
D
lgnition switch ON (ll),
brake fluid reservoir
tull, and parking brake
lever down
Connect to ground: Brake
system light should come on.
. Blown brake system light. An oDen in the wire
GRN/8LU'Driver's door openCheck for continuity to ground:
There should be continuity.
. Faulty driver's door switch. An oDen in the wire
H
Combination light
switch ON.
Check for voltage to g.ound:
There should be battery voltage
Blown No. l9 (1O A) tuse in the
under-dash fuse/relav box
Faulty combination light switch
An oDen in the wire
5
Connect the I terminal
to the J terminal.
Check chime operation: Chime
should activate each time the
batterv is connected,
. Faulty chime. An open in the wire
1H
Combination light
switch ON
Check for voltage to ground:
There should be battery voltage
. Blown No. 19 (1O A) tuse in the
under-dash fuse/relay box. An open in the wire
GRN/BLU1
lgnition switch ON {ll)and turn signal switch
to "Left"
Check for voltage to ground:
It should change from
O-12-O V repeatedly.
Blown No. 26 (10 A) luse in theunder-dash fuse/relav box
Faulty turn signal/hazard relay
An oDen in the wire2GRN/YEL
lgnition switch ON {ll)and turn signal switch
to "Right"
4GRN/WHTlgnition switch ON (ll)
and turn signal switch
to "Left (or Rightl":
Connect the H terminal
to the GRNMHT(or GRN/REDl) terminal.
Check the front side marker
light: Left (or Right) front sidemarker light should come on asthe batterv is connected.
Blown bulb
Poor ground (G2O1, c3O1, G4O1lAn open in the wire
GRN/REDl
23-149