Automatic Heater Control Function

GF83.25-P-2001P Automatic Heater Control Function

MODEL 203.0 /2 /7 up to 23.4.04
- except CODE (580) Air conditioning (or Tempmatic for USA)
- except CODE (580) Automatic air conditioning
- except CODE (581) Automatic air conditioning
- except CODE (581) Comfort automatic air conditioning







A1 Instrument cluster
N10/1 Front SAM control unit with fuse and relay module
N18 HEAT [HAU] control and operating unit
N69/1 Door control unit front left
N69/2 Door control unit front right
N69/3 Left rear door control unit (with models 203.0/2)
N69/4 Right rear door control unit (with models 203.0/2)
N70 Overhead control panel control unit
N73 EIS [EZS] control unit
CAN B Controller area network bus class B (interior compartment) (CAN B)
CAN-C Controller Area Network bus, class C (engine compartment) (CAN C)

All components acting upon the control of the automatic heater (HEAT [HAU]) are networked via CAN-B (CAN-B) with each other.

The following information is available for the electronic control and regulation of interior temperature, air volume and air distribution:
- Interior temperature, sensed by the in-car temperature sensor
- Position of the tilting/sliding roof (SHD) (for model 203.0/2 with code (414) Power glass tilting/sliding roof) or of the panoramic tilting/sliding roof (for model 203.7 with code (413) Panoramic sliding roof), read in by the overhead control panel control unit (N70)
- Position of the windows, read in by the door control units (N69/1, N69/2, N69/3, N69/4)
- Ambient temperature, sensed by the outside temperature display temperature sensor, read in by the front SAM control unit with fuse and relay module (N10/1)
- Battery voltage, coolant temperature and engine speed, read in by the EIS [EZS] control unit (N73)
- Ground speed, by the instrument cluster (A1)

This information is processed by the HEAT [HAU] control and operating unit (N18) and, depending on the preselected setting, used for regulation of the automatic heater (HEAT [HAU]).

In vehicles up to 31.5.02, the in-car temperature sensor is installed in the overhead control panel control unit (N70). As of 1.6.02 the interior temperature is determined by the in-car temperature sensor alone, which is integrated in the HEAT [HAU]) control and operating unit (N18).