Fuel Supply System; Exhaust Gas Recirculation (Egr) System; Positive Crankcase Ventilation (Pcv) System; Fuel Cut-Off Control - Honda 2002 Accord Manual

Fuel and Emissions Systems
System Descriptions (cont'd)
Fuel Supply System
Fuel Pump Control
W h e n the ignition is turned o n , the ECM/PCM grounds
the PGM-FI m a i n relay w h i c h feeds current to the fuel
p u m p for 2 seconds to pressurize the fuel system. W i t h
the engine running, the ECM/PCM grounds the PGM-FI
main relay and feeds current to the fuel pump. W h e n
the engine is not running and the ignition is o n , the
ECM/PCM cuts g r o u n d to the PGM-FI main relay w h i c h
cuts current to the fuel p u m p .
Fuel Cut-off Control
During deceleration w i t h the throttle valve closed,
current to the fuel injectors is cut off to improve fuel
economy at speeds over 1,100 r p m .
Fuel cut-off action also occurs w h e n engine speed
exceeds 6,500 r p m , regardless of the position of the
throttle valve, t o protect the engine f r o m over-revving.
On A/T models, w h e n the vehicle is stopped, the PCM
cuts the fuel at engine speeds over 5,000 r p m .
PGM-FI Main Relay
The PGM-FI relay contains t w o separate relays. One is
energized whenever the ignition is on which supplies
battery voltage to the ECM/PCM, power to the fuel
injectors, and power for the second relay. The second
relay is energized to supply p o w e r to the fuel p u m p for
t w o seconds w h e n the ignition is switched ON (II), and
w h e n the engine is running.
N o .
2
N o .
1
N o . 3
N o . 4 N o . 5 N o . 6 N o . 7
Exhaust Gas Recirculation (EGR) System
Refer to the System Diagram to see the functional
layout of the system.
EGR Valve
The EGR valve is designed to lower peak combustion
temperatures and reduce oxides of nitrogen emissions
(NOx) by recirculating exhaust gas through the intake
manifold and into the combustion chambers.
Positive Crankcase Ventilation (PCV) System
The PCV valve prevents blow-by gasses f r o m escaping
into the atmosphere by venting t h e m into the intake
manifold.
B R E A T H E R
H O S E
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