how to diagnose and repair
 

I've got a 2006 Saab 9-3 2.0T. A few weeks back, the ABS, stability control, and TCS warnings all came on and haven't gone off. Also my reported gas mileage fell to 12, it's usually 24 for my city driving.

I had an old mechanic check the brakes, all hydraulics are fine, but he didn't have the equipment to read codes. All posts I've read about similar symptoms point to a rear speed sensor.

Can anyone tell me how to confirm this is what's wrong without having to pay a dealers shop a lot of money for diagnostics? Also how to repair it if the speed sensor is what is wrong?

Thanks,
Joel

new symptom
 

Here's a new symptom I just started noticing today. I hit the trip gauge before I left work. Distance between work and home is 8.4 miles, but the trip gauge says I only went about 4.1-4.3 miles.

I guess this syncs with the symptom about halving my gas mileage average. Anyone ever had this happen?

I own a 2001 9-3, and i am having the exact same issue. I paid 120.00 to have the computer read. The guy said it was a faulty ABS module. It appears it somehow got water inside the connection. I need to find a salvage yard that might have a 2001 in it. Hope I was of SOME help.