MAC-14 voltage divider mod - how to identify?

Eyvind Spangen eyvind.spangen at
Fri Apr 27 15:27:21 EDT 2001

I suspect the MAC-14 ECU in my '90 200TQ has been a "victim" of a voltage 
divider mod, as the dashboard gauge never shows more that 1.3, it shows 0.7 
with engine off, it runs better than a 3600 lb car with 160 hp "should", and 
the PO told me that it was chipped.

I opened up the ECU to take a look, and I found no home-made soldering or 
wires connected to the pressure transducer, but nevertheless the fooled up 

I understand that I need to measure the boost with an external gauge to be 
sure, but I have to get one first (will do the following week).. :-)

The wastegate looks like it has been fooled with - new diaphragm installed, 
and the whole thing looks newer than 11 years..

I guess that a 1.8 bar spring and a voltage divider of some sort has been 
installed.. If I apply pressure to the boost line to the ECU, I won't get more 
than 1.5 on the display, even if I feed 2.0 absolute pressure.. Looks like the 
divider is constructed to avoid the 1.6 fuel pump cutout..

Anyone know anything? BTW, how much does a "real" chip mod (like the SJM chip) 
run these days?


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