S4 Sedan L5-2226cc 2.22L DOHC Turbo (AAN) (1992)
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A/C Compressor Signal: Description and Operation
A/C Compressor Signal
The A/C Compressor Signal is connected to pin 6 of the Motronic control module, the signal is bidirectional (PIN 6 - INPUT + OUTPUT).
This signal is a communication link between the A/C control head, Motronic control module and the transmission control module. Signal flow to or
from the Motronic control module is as follows:
Signal IN
^
When switching the A/C compressor ON, the idle air control valve is opened further in order to compensate for the higher engine load.
Signal OUT - manual transmission only
^
The compressor is switched OFF for a maximum of 12 seconds at a vehicle speed of less than 4 mph when the throttle valve is opened
quickly (acceleration).
Signal OUT - automatic transmission only
^
The compressor is switched OFF for a maximum of 3 seconds in first gear (recognized from vehicle speed and engine speed) with a throttle
valve opening of more than 65° (full load).
