Compressor Speed Sensor: Description and Operation

Compressor Lock Signal - 12cyl. Vehicles Only
This signal provides the Air Conditioning Control Module (A/CCM) with compressor rotation speed. This is then compared with engine rotation speed.

If the ratio of the compressor speed against engine speed drops below the A/CCM limits, indicating compressor/belt slippage, the compressor clutch is disengaged.

When compressor clutch disengaging commences the A/C LED on the control panel will flash once per second.