I will usually look for the obvious on a circuit board but anything past that is usually not worth my time. Understand that because I own and run a Volvo repair shop I cannot enjoy the luxury of fixing stuff like that. When you have to provide a written warranty on your repairs you try to balance between the absolute best parts and service you can provide while remaining competitively priced. I have soldered my share of bulb failure sensors, fuel pump relays, and a/c control units back together for sure. Although I have not gotten into it, it is my understanding that the ABS ECU repair is just more of the same, open them up and solder the same darn failed solder joints back together. You see some rebuilders talk about how they put in "upgraded parts", to that I say yeah right. I know one of the bigger players in that field and he says they just solder them back together and don't look back.

Mark