Faulty auto check switch/trip computer??

Jonas Majauskas jmajau at balt.net
Tue Jan 20 14:37:42 EST 2004

On Tue, 20 Jan 2004, Richard E. Berlin, Jr. wrote:

> For months now, I've been getting weird scrambled images on the
> pictogram, so a few weeks ago, I pulled the cluster and checked
> all connections. This yielded no improvement. So.....last week I
> bit the bullet and bought a new unit (ouch) and installed it. The
> good news is that the pictogram works beautifully, as do the BAR
> and average mph. functions. The bad news is that now the average
> mpg function and miles to empty reads at a constant 200mpg., and
> 2000 miles to empty. The unit will reset to 0.00, but immediately
> jumps back to 200mpg (I wish!).
> Do any of you have any ideas, or do you think I have spent $450 to
> acquire a faulty unit.? Thanks so much for any advice.

You should check the 6 position switch on the top of instrument cluster -
if my memory serves me, the 1,2,3 positions have label "Benzin", and 4,5,6
are called "Diesel". Also there is label "EG" for 1 and 4, "US"
(something familiar?:) ) for 2 and 5, and "RW" for 3 and 6. My european
200q20v instrument cluster is set to position 6, "Diesel" + "RW", but I am
not the first who disassembled the instrument cluster :-/

My sugestion is to play with this switch - logical position for you can be
"Benzin"+"US", but why do I have "Diesel" ? Very strange. I will try all
the combinations when my car will be ready :-)

Another theory - instrument cluster (the "autocheck" unit in instrument
cluster) does not get fuel tank level signal. I assume fuel gauge is ok,
isn't it ? Then there must be something in instrument cluster. Maybe that
6-position switch. Or maybe the plug on the back of instrument cluster, on
driver side. Maybe you should try the plug from your old instrument

P.S. have you tried resoldering sockets on your old instrument cluster ? I
heard that this trick can help. But soldering iron should not exceed 20W.

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