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A/C compressor control

A/C compressor control





A/C compressor engagement is controlled by functions in DICE as well as in EDC 15. The following description covers the functions in EDC 15.

The A/C compressor function comprises two sub-functions


- logic function

- control function


Logic function

The logic function determines when the A/C compressor should be turned off. This is performed so that the A/C compressor can be turned off under certain driving conditions when maximum engine torque must be available.

The A/C compressor is turned off under the following conditions


- Engine coolant temperature above 118° C (244° F)

- Pedal position sensor value greater than 95% and engine speed < 2500 rpm while in first gear

- Engine speed < 600 rpm


Control function

The control function turns the A/C relay on and off when commanded by the logic function.

When the final stage control has amplified the signal, pin 41 is grounded and the A/C relay energizes the A/C compressor solenoid clutch.