Operation CHARM: Car repair manuals for everyone.

A/C Compressor Control









Regulation of the A/C Compressor relay is an output of the ECM. As with Bosch and Siemens systems, the EGM controls the A/C compressor relay based on signals from the IHKA/IHKR control modules.

When the IHKA/IHKR control module requests compressor activation, the ECM prepares for the additional load of the compressor by modifying the ignition timing and stabilizing idle speed.

The A/C compressor is cut off during WOT acceleration at low speeds to allow the engine to achieve maximum power.