Toyota Repair: 2002 Sienna ABS, wheel speed, electronic stores

Question
We bought a used Sienna last year and it was working great until a few months ago.  The ABS and brake lights started turning on, the speedometer would intermittently work (if you stopped at a stoplight it would stop working, but if you turned the van off with the ignition and back on the speedometer would work again), and when the speedometer didn't work the van seemed to stutter badly when accelerating.  We spoke to one dealer that said it was a wheel sensor and would cost $400 (but that it didn't need to be fixed right away), since then the problem has gotten worse, with the speedometer failing more frequently. The next dealer we took it to (we are on vacation) said it was the ABS ECU with a $1900 repair bill.  Also at about the same time the radio stopped working (don't know if this is related), but another individual at the dealership who installs radios for one of the big electronic stores said he wouldn't reinstall a radio in a car with a ECU problem because that could cause the radio to fail again.  Help, $2K is alot...

thanks
Jeff

Answer
In order for me to be of any help at all I will need to know all of the diagnostic trouble codes that are now present in the computer or have been in the past, I have no idea if the abs ecu is bad or not or even if a wheel speed sensor is bad without having that information. The radio is on a completely different electrical circuit and has nothing to do with this.