Engine and Emission Control System Description - Fuel Pump Control / Air Regulator Control
EF & EC-384prose procedureFuel pump and air regulator timing differ by engine: SR20DE operates for 5 seconds, SR20DET for 1 second, when ignition is turned ON.
Fuel Pump Control
INPUT/OUTPUT SIGNAL LINE
SYSTEM DESCRIPTION
The E.C.U. activates the fuel pump for several seconds after the ignition switch is turned on to improve engine startability. If the E.C.U. receives a 180° signal from the crank angle sensor, it knows that the engine is rotating, and causes the pump to perform. If the 180° signal is not received when the ignition switch is on, the engine stalls. The E.C.U. stops pump operation and prevents battery discharging, thereby improving safety. The E.C.U. does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.
Fuel Pump Operation
Ignition switch is turned on to ON.
Fuel pump operationSR20DE: Operates for 5 seconds / SR20DET: Operates for 1 second
Engine running and cranking
Fuel pump operationOperates
When engine is stopped
Fuel pump operationStops in 1 second
Except as shown above
Fuel pump operationStops
Air Regulator Control
INPUT/OUTPUT SIGNAL LINE
SYSTEM DESCRIPTION
The air regulator is controlled by the E.C.U. at the same time as fuel pump ON-OFF control.
Air Regulator Operation
Ignition switch is turned ON
Air regulator operationSR20DE: Operates for 5 seconds / SR20DET: Operates for 1 second
While engine is running and cranking
Air regulator operationOperates
When engine is stopped
Air regulator operationOFF in 1 second
Except as shown above
Air regulator operationOFF