I recently had the crud controls serviced on my faithful Cirrus -- at around
110,000km the crankshaft position sensor was getting flaky. As part of this 'fix' the (five-star) dealer installed a software 'upgrade' on the TCM (from the base factory build). This definately changed the driving characteristics of the vehical -- it is just not as lively and fuel economy is not as good. Prior to the upgrade I was getting mid-30s to 40mpg on a long drive, now it struggles to get 34. And there are occasional anomalous shfts where it seems to go into a lower ratio for a few minutes -- engine rpm drops mb 500 rpm with no change in speed.
Does anyone know what is going on? Is there some way this can be backed out?
thanks,
greg