Why a computer in cluster (was: Gremlins in Tank)

[John Firestone <john.firestone@xxxxxxxxxxxx>]

Scott Miller writes:
> 
> New BMW gas gauge:  Sender in tank, wires to computer, wires from
> computer, gauge in dash.
> 
> Question:  Why does the gas gauge need a computer?

Several reasons I expect:

   - to detect faults in the fuel sender signal (shorts to ground, to +12,
     intermittent connections, faulty senders and nonsensical readings);

   - to pinpoint problems with the fuel gauge via the cluster system test;

   - to monitor the fuel senders via the workshop DIS computer;

   - to simplify the low fuel warning and make it more repeatable;

   - to simplify the OBC and insure its displayed RANGE is consistent
     with the instrument cluster;

   - to allow easy, software downloads to the cluster (coding data) that 
     adjust for differences among models or changes over different 
     model years (e.g. a different tank size).

- -John
'96 318is
john.firestone@domain.elided

     

------------------------------