A/C Pressure Switch

The A/C pressure switch consists of a high-low pressure switch (A/C pressure switch A) and a middle pressure switch (A/C pressure switch B).

• High-low pressure switch

  If the refrigerant pressure becomes too high (due to blockage or lack of airflow at the condenser), or too low (due to leakage), the A/C pressure switch stops the A/C request signal to the PCM and the A/C compressor stops operating.

  Fig 1: A/C Pressure Switch Working Pattern

  Courtesy of AMERICAN HONDA MOTOR CO., INC.
• Middle pressure switch

  If the refrigerant pressure goes above 1,520 kPa (15.5 kgf/cm² , 221 psi), the A/C pressure switch closes to signal the PCM to change the speed of the A/C condenser fan and radiator fan to high. When the refrigerant pressure drops below 930 kPa (9.5 kgf/cm² , 135 psi), the A/C pressure switch opens to signal the PCM to change the speed of the A/C condenser fan and radiator fan to low.

  Fig 2: Middle Pressure Switch Working Pattern And Pinout

  Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 3: A/C Air Flow Mode (1 Of 2)

Courtesy of AMERICAN HONDA MOTOR CO., INC.

Fig 4: A/C Air Flow Mode (2 Of 2)

Courtesy of AMERICAN HONDA MOTOR CO., INC.