Operation, 1-Speed Fan
WARNING: This page is about a different car, the 2001 Saab 9-3. However, it is still accessible from the selected car via links, so may be relevant.
For certain markets, cars are equipped with a radiator fan that can run at only one speed. It is controlled by DICE (628) via a relay (155). If any of the conditions is fulfilled, DICE operates the relay (155) via pin 35 and the fan motor is supplied with current.
The control module uses the following input signals for switching the radiator fan on and off.
- Coolant temperature (bus from Trionic T7)
- A/C pressure (own pressure gauge)
- Car speed (bus from MIU)
- Outside temperature (bus from SID)
- A/C system status (active/inactive)
The fan is activated when coolant temperature matches or exceeds the preset values.
If the A/C system is active, the radiator fan can be activated in any of the following cases:
- the outside temperature exceeds 22 °C (72°F)
- vehicle speed is below 38 km/h and the A/C pressure exceeds 9 bar.
WARNING:
Do not touch the fan before unplugging its connectors.