Fuel Pump Control Circuit

SYSTEM DESCRIPTION

Fuel pump ON-OFF control
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine start-up. If the ECM receives a 10 signal from the camshaft position sensor, it knows that the engine is rotating, and causes the pump to activate. If the 10 signal is not received when the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents the battery from discharging, thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn controls the fuel pump.

Condition Fuel pump operation
Ignition switch is turned to ON Operates for 5 seconds
Engine is running and cranking Operates
When engine is stopped Stops for 1.5 seconds
Except as shown above Stops




CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Specification data are reference values.




ECM TERMINALS AND REFERENCE VALUE
Specification data are reference values, and are measured between each terminal and (128) (ECM ground).

EC-F/PUMP-01:

EC-F/PUMP-01 - Connector View:

WIRING DIAGRAM

M12,M4,M6,E66,B3,N1,M11,M48,D1,D21 Connector Views:

M3,B4,M50,B101,M49,F63,E70,E81 Connector Views:

M1 Connector View:

Part 1 Of 2:

Part 2 Of 2:

DIAGNOSTIC PROCEDURE

COMPONENT INSPECTION







Fuel pump relay
Check continuity between terminals (3) and (5).
If NG, replace relay.




Fuel pump
1. Disconnect fuel pump harness connector.
2. Check resistance between terminals (1) and (3).

Resistance: 0.2 - 5.0 Ohms at 25 °C (77 °F)

If NG, replace fuel pump.