I've just got my 99 FRC error messages cured, but not before a lot of trial and error work happened. The only code my car was throwing was a C1225, left front wheel speed variation indicated. I checked the wiring even replaced the jumper harness with a new on with no changes seen, all of the lights, traction control active handling and so forth came on. Bill Curlee and I talked this over several times, I Ohmed the wheel pickup per the manual and it checked good, I watched the sensors work on a Snap-on Solace scanner both wheels matched perfectly. I ohmed the wiring all the way back to the ECBM and it checked good. Well Bill and I decided the ECBM must be bad so my search was on for a good used Letter V ECBM. I found one in Texas through a man named Johnathon Snelling, I bought it (it cost a lot) got it in here and installed the unit and much to my surprise my lights still came on, showing the same trouble code as before, this was tough to swallow. I contacted Johnathon, this guy is awesome to work with, He was to the point of finding me another unit but knew this one was good. After a couple of weeks trying to decide what to do and keeping in touch with Johnathon I decided to change the wheel bearing assembly anyway just to be sure and I already had a spare, so why not. As luck would have it all of the lights went out and no more codes were thrown. Keep in mind I used the GM manual to determine the ECBM needed to be replaced. I next removed Jonathon's ECBM and installed my old unit and the lights stayed out. Johnathon seemed as happy as I am that fixed my problem and verified his ECBM is good. He let me return his unit for a full refund, I couldn't justify that much money for a spare I may never unit. I told this story just to let anybody that might really need a letter V, ECBM that Jonathon now has one that "I" know is "Good". He gets other hard to find used parts also. I'll PM his # to anyone that needs it, but i'll be driving this FRC to the Tail of the Dragon. leaving 7-14 and won't be back till Friday to send PM's.