Acura 1994 Integra Service Manual page 231

PGM-FI System
System Description
ENGINE CONTROL MODULE (ECMI
OUTPUTS
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. The
basic discharge duration, after being read out from the memory, is turther modilied by signals sent from vanous sensofs
to 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 Control
a The ECM contains mamories for basic ignition timing at various engine speeds and manifold pressures. lgnition timing
is 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
( B 1 8 C l e n g i n e ) .
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 supplies
current 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 cuts
current to the fuel pump.
TDC/CKP/CYP Sensor
MAP Senso.
ECT Sensor
IAT Sensor
TP Sensor
H O 2 S
vss
BARO Sensor
E L D
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)
M I L
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
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