A/C Pressure Sensor

The A/C pressure sensor converts A/C pressure into electrical signals to the PCM.

VOLTAGE SPECIFICATIONS

A/C System Pressure⁽¹⁾

Sensor Output Voltage (V out)

System Operation

Abnormally low pressure: Below 196 kPa (2.0 kgf/cm² , 28 psi)

Below 0.685 V

The PCM disengages the A/C compressor clutch. The radiator and A/C condenser fans operate based on engine coolant temperature.

Normal operating pressure:

Above 196 kPa (2.0 kgf/cm² , 28 psi)
Below 1,470 kPa (15.0 kgf/cm² , 213 psi)

0.686 V to 1.944 V

The PCM cycles the A/C compressor clutch based on cooling demand. The radiator and A/C condenser fans operate at low speed unless the engine coolant temperature exceeds 206°F (97°C)

High operating pressure:

Above 1,470 kPa (15.0 kgf/cm² , 213 psi)
Below 3,138 kPa (32 kgf/cm² , 455 psi)

1.945 V to 4.575 V

The PCM cycles the A/C compressor clutch based on cooling demand. The radiator and A/C condenser fans operate at high speed.

Abnormally high pressure: More than 3,138 kPa (32 kgf/cm² , 455 psi)

Above 4.575 V

The PCM disengages the A/C compressor clutch. The radiator and A/C condenser fans operate based on engine coolant temperature.

⁽¹⁾	The A/C system pressure can be monitored through the climate control sensor input display function (see DISPLAYING SENSOR INPUTS AT THE CLIMATE CONTROL UNIT ).

The response of the A/C pressure sensor is shown in the graph.

NOTE: When the refrigerant is below 196 kPa (2.0 kgf/cm² , 28 psi) or above 3,138 kPa (32 kgf/cm² , 455 psi), the PCM turns the A/C compressor clutch relay off to protect the A/C compressor. When the refrigerant pressure is above 1,470 kPa (15.0 kgf/cm² , 213 psi), the PCM switches the radiator and A/C condenser fans to high speed.

Fig 1: Identifying AIC Pressure Sensor Connector And Graph

Courtesy of AMERICAN HONDA MOTOR CO., INC.