Pgm-Fi System; Camshaft Position (Cmp) Sensor B; Air Conditioning (Alc) Compressor Clutch Relay; Air Fuel Ratio (A/F) Sensor - Honda Civic 2002-2003 Service Manual

Fuel and Emissions Systems
System Descriptions (cont'd)
PGM-FI System
The Programmed Fuel Injection (PGM-FI) system is a
sequential multipart fuel injection system.
Air Conditioning (AlC) Compressor Clutch Relay
When the ECM receives a demand for cooling from the
AlC system, it delays the compressor from being
energized, and enriches the mixture to assure smooth
transition to the AlC mode.
Air Fuel Ratio (A/F) Sensor
The AlF Sensor operates over a wide air/fuel range. The
AlF Sensor is installed upstream of the TWC, and sends
signals to the ECM which varies the duration of fuel
injection accordingly,
Barometric Pressure (BARO) Sensor
SENSOR
TERMINALS
HEATER
TERMINALS
The BARD sensor is inside the ECM. It converts
atmospheric pressure into a voltage signal that the ECM
uses to modify the basic duration of the fuel injection
discharge.
11-26
Camshaft Position (CMP) Sensor B (Top Dead Center
(TOC) Sensor)
The CMP sensor B (TOC sensor) detects the position of
the No.1 cylinder as a reference for sequential fuel
injection to each cylinder.
MAGNET
Crankshaft Position (CKP) Sensor
The CKP sensor detects crankshaft speed and
determines ignition timing and timing for fuel injection
of each cylinder as well as detecting engine misfire.
MAGNET
Engine Coolant Temperature (ECT) Sensor
The ECT sensor is a temperature dependent resistor
(thermistor). The resistance of the thermistor decreases
as the engine coolant temperature increases.
THERMISTOR