System Description

ECM INPUT SIGNAL CHART

Sensor

Input Signal to ECM

ECM function

Actuator

Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)

Engine speed⁽¹⁾

Fuel pump control

Fuel pump control module (FPCM)

Mass air flow sensor

Amount of intake air

Engine coolant temperature sensor

Engine coolant temperature

Battery

Battery voltage⁽¹⁾

⁽¹⁾	ECM determines the start signal status by the signals of engine speed and battery voltage.

This system controls the fuel pump operation. The amount of fuel flow delivered from the fuel pump is altered between two flow rates by the FPCM operation. The FPCM determines the voltage supplied to the fuel pump (and therefore fuel flow) according to the following conditions.

VOLTAGE REFERENCE CHART

Conditions	Amount of fuel flow	Supplied voltage
Engine cranking Engine coolant temperature is below 10°C (50°F). Engine is running under heavy load and high speed conditions	high	Battery voltage (11 - 14 V)
Except the above	low	Approximately 8 V