High Pressure Sensor

A/C Refrigerant System Component Description

High Pressure Sensor





• Depending on engine type, refrigerant systems have either an A/C Pressure Switch (F129) or High Pressure Sensor (G65) installed. Refer to appropriate wiring diagram.

High Pressure Sensor (G65) - B -, transmits a square wave signal to Coolant Fan Control (FC) Control Module (J293) at a rate which varies according to the refrigerant system pressure. The signal is processed as follows:

Based on the signal transmitted by High Pressure Sensor (G65), Coolant Fan Control (FC) Control Module (J293) determines the A/C refrigerant system pressure and controls A/C Clutch (N25) and Coolant Fan functions accordingly. For example:

• Switches the Coolant Fan (V7) to the next higher speed when pressure in the refrigerant circuit increase.

• Switches off A/C Clutch (N25) when pressure is excessive (for example when engine cooling is insufficient).

• Switches off A/C Clutch (N25) off when pressure is too low (for example with low/no refrigerant).

The High Pressure Sensor (G65) signal is also input to the Motronic Engine Control Module (ECM). As the amount of torque needed to drive the A/C compressor varies according to refrigerant system pressure, the ECM processes this signal in order to enhance engine performance.

High Pressure Sensor (G65) signal, checking => [ High Pressure Sensor, Function ] High Pressure Sensor, Function.