PRE-RELEASE
A/C compressor
| A/C compressor |
When the A/C compressor is activated, either by the ACC control module or by means of the A/C button on the dashboard, battery positive voltage (B+) is applied to pin 64 of the Motronic control module from the ICE module via the antifrost thermostat and pressure switch.
The control module then opens the idle air control valve slightly more to prepare for the forthcoming load increase. After a short delay the control module grounds pin 48 which controls the A/C relay.
The engine control module breaks the circuit to pin 48 if the engine has not yet been started.
