Engine and Emission Control System Description
EF & EC-19prose procedureFuel Pump Control
INPUT/OUTPUT SIGNAL LINE
Fuel Pump Control Input/Output Signal Line
Computing layout…
Wire Details
| From | To | Color |
|---|---|---|
| c1 | c3 | |
| c2 | c3 | |
| c3 | c4 | |
| c3 | c5 |
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 1° signal from the crank angle sensor, it knows that the engine is rotating, and causes the pump to rotate. If the 1° 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 ON/OFF of the fuel pump relay, which in turn controls the fuel pump.
Fuel pump and air regulator ON-OFF control
| Ignition switch position | Engine condition | Fuel pump/ Air regulator operation |
|---|---|---|
| ON | Stopped | Operates for 5 seconds |
| ON | Running | Operates |
| ON | After stopped | Stops after 1 second |
| START | Starting | Operates |
ON
Engine conditionStopped
Fuel pump/ Air regulator operationOperates for 5 seconds
ON
Engine conditionRunning
Fuel pump/ Air regulator operationOperates
ON
Engine conditionAfter stopped
Fuel pump/ Air regulator operationStops after 1 second
START
Engine conditionStarting
Fuel pump/ Air regulator operationOperates
Air Regulator Control
SYSTEM DESCRIPTION
The air regulator is controlled by the E.C.U. at the same time as fuel pump ON-OFF control.
Fuel Pressure Regulator Control
INPUT/OUTPUT SIGNAL LINE
Fuel Pressure Regulator Control Input/Output Signal Line
Computing layout…
Wire Details
| From | To | Color |
|---|---|---|
| c1 | c5 | |
| c2 | c5 | |
| c3 | c5 | |
| c4 | c5 | |
| c5 | c6 |