My Alfa 147 is behaving strange lately. The whole story started with a punctured front right tyre last week, and because fronts were quite worn, I decided to buy a new pair of tyres and put them on the rear axle, but rears were quite good and so I decided to mount them on the front axle...
After that my car became completely undriveable. It feels like rear has no grip at all. And also VDC is coming on all the time for no reason at all but only in the left corners... It is not because of excesive speed, it activates itself even at speeds well under the speed limit. At the moment when VDC activates cars grip is OK.
But if I push it rear tyres loose the grip much earlier than they used to, and the rear end is very unstable.
Tyres are Dunlop Sport Maxx TT (my old tyres are also the same model) and the DOT is 5209.
At first I was hoping that it was just the upper layer of the rear tyres that needs to be worn to get good grip, but now after 200km it is still exactly the same.
Today I went for a 4 wheel alignement, but that was completely OK, it needed just minor adjustements, and it made no difference at all. The guy who did the alignement also checked all whisbones and arms, but there was also nothing to be found.
I connected to the ABS ECU with Fiat ECU scanner, and there are no errors present. I tested all 4 wheel speed sensors and they are also working just fine (all four reporting same speed when traveling straight). I checked steering wheel angle sensor, jaw sensor and latteral aceleration sensor which all seem to be working fine, only the lateral acceleration sensor reports side forces between 0.192 and 0.384 m/s^2 (that is something like 2-4% of 1G force) when the car is stationary. When driving lateral forces seem to be reported OK, it is only that offset when stationary that bothers me just a little bit. But I'm not sure if that is the problem, because this seems like quite small percentage.
Now I dont have idea what is the problem. Maybe some of you guys could give me an advice what could I do?
Is there a chance that my ABS/VDC ECU is broken?
Is there any kind of calibration that could be done on the ABS/VDC computer with Examiner?
Are my new rear tyres crap?