Fuel Pump Control

Fuel Pump Control:

PURPOSE AND OPERATION
The Engine Control Module (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 1 signal from the camshaft position sensor, it knows that the engine is rotating, and causes the pump to activate. If the 1 signal is not received when the ignition switch is on, the engine stalls. The ECM stops pump operation and prevents battery 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. Fuel Pump operation is as follows:

^ Ignition switch is turned to ON: Fuel pump Operates for 1 second

^ Engine running and cranking: Fuel Pump Operates

^ When engine is stopped: Fuel Pump Stops in 1.5 seconds

^ Except as noted above: Fuel Pump Stops