A/C Function

WARNING: This page is about a different car, the 1998 Saab 900, 1997 Saab 900, 1996 Saab 900, 1995 Saab 900, and 1994 Saab 900. However, it is still accessible from the selected car via links, so may be relevant.

The A/C function is activated with the A/C switch or, alternatively, from the ACC unit. The ICE records the coolant temperature and, if the temperature is below the temperature for A/C cycling, the ICE sends a signal on terminal 11 to the engine control system's electronic control module by switching on the A/C compressor.

The engine control system's electronic control module first compensates for the coming load increase and about 0.1 seconds after that, the A/C compressor comes on. If the maximum temperature for A/C cycling is reached, the ICE sends a signal to the engine control system's electronic control module to switch off the A/C compressor. In the same way as when the A/C compressor is started, the engine control system's electronic control module compensates the idling speed before the A/C goes off. See Fig 1 .

Fig 1: Identifying A/C Function

Courtesy of SAAB-SCANIA OF AMERICA, INC.