Golf III L4-1984cc 2.0L SOHC (1993)
A/C Signal: Description and Operation
A/C Compressor Signal
The A/C Compressor Signal is connected to pin 37 of the Motronic control module, the signal is bidirectional (PIN 37 - INPUT + OUTPUT).
This signal is a communication link between the A/C control, Motronic control module and the transmission control module. Signal flow to or from the
Motronic control module is as follows:
Signal IN
^
Before switching the A/C compressor ON, the idle air control valve duty cycle is modified 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).