ALFB Load Accounting System (Renault Espace III)

The load dependent function (LFB) aims to convert the pressure into a voltage signal during deceleration and low load in order to reduce fuel consumption. The solenoid valve (AFLB), controlled by the engine control unit, is a device that cancels the LFB function when the engine is cold.

The functioning of ALFB depends on various parameters:

• air and coolant temperatures when the ignition is turned on (see fig. 3.25);
• in high-altitude areas, the ALFB is switched off significantly later depending on the air temperature. Thus, the excitation time of the electromagnetic valve is increased;
• load and crankshaft speed: for reasons of cleaning from dirt and noise, AFLB is activated:
• if the coolant temperature is between 65°C and 80°C;
• if the engine speed is between 1350 and 1900 min⁻¹;
• in all cases, ALFB is deactivated if the engine speed exceeds 3050 min⁻¹, when the engine is running at full load.

(This note was copied from the resource: www.RenaultBook.ru)