Compressor Signaling '99 Model Year

COMPRESSOR SIGNALING '99 MODEL YEAR







For '99 Model Year, E39 IHKA now receives a variable input from the refrigerant pressure "sensor". The sensor is mounted in the receiver/driver.

Based on the refrigerant pressure, the pressure sensor input allows the IHKA module to determine the "start up" torque of the A/C compressor. It the pressure is too low or high the compressor will be deactivated. The IHKA also anticipates the necessary [1][2]auxiliary fan speed and passes this information on to the ECM via the K-bus.

This change now removes the pressure sensor from the compressor activation circuit.