Pgm-Fi System; Engine Control Module (Ecm); Powertrain Control Module (Pcm) - Honda CR-V 1997 Service Manual

PGM-FI System
System Description
ENGINE CONTROL MODULE (ECM)/
INPUTS POWERTRAIN CONTROL MODULE (PCM) OUTPUTS
CKPITDC/CYP Sensor
CKF Sensor
MAP Sensor
ECT Sensor
IAT Sensor
TP Sensor
I
Fuel Injector Timing and Duration
I
Primary H02S
Secondary H02S
[ Electronic idle Control
I
VSS
=;
=>
KS*5
BARO Sensor
I
Other Control Functions
I
ELD*6
[Ignition Timing Control
I
Starter Signal
AL T FR Signal
Air Conditioning Signal
I
ECM/PCM
Back~up
Functions
I
AfT
Gear Position Signal*'
I
AfT
Control Functions I
Battery Voltage (lGN.1)
Brake Switch Signal
PSP Switch Signal
Fuel Tank Pressure Sensor*.·
*5
Countershaft Speed
Sensor*l
Mainshaft Speed Sensor*l
OVER-DRIVE Switch Signal*'
PGM-FI System
The PGM-FI system on this model is a sequential multiport fuel injection system.
Fuel injector Timing and Duration
Fuel Injectors
PGM-FI Main Relay (Fuel Pump)
MIL
lAC Valve
AlC Compressor Clutch Relay
Radiator Fan Relay
Condenser Fan Relay
ALT
ICM
EVAP Purge Control Solenoid
Valve
Primary H02S Heater
Secondary H02S Heater
EVAP Bypass Solenoid Valve H , *5
EVAP Control Canister Vent Shut
Valve
H
. *5
DLC
Lock-up Control Solenoid Valve*'
Shift Control Solenoid Valve*l
AfT
Clutch Pressure Control
Solenoid Valve*'
04 Indicator Light*"
*3,
*"
D Indicator Light*"
*5
OVER-DRIVE OFF Indicator
Light*l,
*~
*1:
AJT
*2: MIT
*3: '97 model
* 4: '98 model
*5: '99 - 00 models
*6: USA
The ECM/PCM contains memories for the basic discharge durations at various engine speeds and manifold pressure. The
basic discharge duration, after being read out from the memory, is further modified by signals sent from various sensors
to obtain the final discharge duration.
Idle Air Control
Idle Air Control Valve (lAC Valve)
When the engine is cold, the AlC compressor is on, the transmission is in gear, the brake pedal is depressed, the PIS load
is high, or the alternator is charging, the ECM/PCM controls current to the lAC Valve to maintain the correct idle speed.
Ignition Timing Control
• The ECM/PCM contains memories for basic ignition timing at various engine speeds and manifold air flow rates.
Ignition timing is also adjusted for engine coolant temperature.
• A knock control system was adopted which sets the ideal ignition timing for the octane rating of the gasoline used.*5
Other Control Functions
1. Starting Control
When the engine is started, the ECM/PCM provides a rich mixture by increasing fuel injector duration.
2. Fuel Pump Control
• When the ignition switch is initially turned on
(11),
the ECM/PCM supplies ground to the PGM-FI main relay that
supplies current to the fuel pump for two seconds to pressurize the fuel system.
• When the engine is running, the ECM/PCM supplies ground to the PGM-FI main relay that supplies current to the
fuel pump.
• When the engine is not running and the ignition is on, the ECM/PCM cuts ground to the PGM-FI main relay which
cuts current to the fuel pump.
11-80