General Information

SIA III

Models: E38, E39, E53, E36/5, E36/7

Production: 1996 onward excluding E36 (except E36/5 and E36/7 from 9/98)

SIA III Components:




- Instrument Cluster with LED display.
- DME

Instrument Cluster (IKE, KOMBI) with LED Display
The Instrument cluster calculates the Service Interval. The cluster is also responsible for displaying the LED blocks used to represent time until next service.

DME
The DME provides the Fuel Consumption signal (ti) as the only signal used in the SIA calculation.

Principle of Operation
The sequence for displaying the necessary service is similar to SIA II, The calculation method however differs significantly.

The Instrument Cluster calculates the Service Interval based only on the input of the "ti" signal (Fuel consumed) from the DME. This method gives an accurate indication of engine load and the need for service.

The SIA data for the specific model is coded into the instrument cluster. The data consists of a Stored quantity of fuel, referred to as the "Coded Inspection Limit". The "Coded Inspection Limit" varies according to model and can be viewed using the Diagnosis Program. (See Workshop Hints)




The processor of the Cluster receives the ti signal when the vehicle is used. As 20% of the stored volume is consumed one of the green LEDs will go out. Each successive 20% of fuel consumed will cause the next LED to go out until 100% of the stored value has been consumed. At this point the yellow LED comes on indicating the service that is necessary. At 108% of the volume, the red LED will illuminate indicating a service which is overdue.

When the Service Interval Indicator is reset, the total stored volume of fuel is restored in the cluster and the calculation starts over again.