General: cooling system Citroen C8 I

Foreword

FRIC (cooling function integrated into the engine ECU)

BRAC (air conditioning need for cooling)

The cooling function is controlled by the engine ECU (F.R.I.C), contrary to the old designs, where the function was controlled by the coolant temperature unit

This function monitors the engine cooling fan while the engine is running

This strategy is developped depending on the following parameters

• Engine coolant temperature
• Requirements from air conditioning functions
• Requirements for automatic gearbox oil cooling (the coolant / oil exchanger)

The engine ECU supplies the following parameters to the built-in systems interface

• Engine coolant temperature (coolant fluid)
• Information on the engine coolant temperature alert
• Air conditioning circuit pressure

The cooling requirement linked to air conditioning is supplied by the function B.R.A.C (cooling requirement of the air conditioning), also incorporated in the engine ECU

A linear pressure sensor allows the pressure of the cooling circuit to be measured, which enables the engine ECU to control the slow or fast speed of the fan unit

Contrary to the voltage pressure switche, the linear pressure sensor supplies a voltage proportional to the Air con circuit pressure

8007: linear pressure sensor

Diagram of the cooling function

Key

• Single arrow: wire connection
• Triple arrow: multiplexed connection

Configuration according to engine type

EW engine

The cooling system consists of the following components

DW, ES9 engine

The cooling system consists of the following components