My car (2009 LS) was just diagnosed with code C0550 (ECU internal fault). My brake, abs and traction light is on and won't go off. All speed sensors are good. After driving the car and multiple failed attempts to get the ABS to engage and clearing codes the mechanic said it was most likely the abs control module. There are no other issues such as shifting strange or speedometer not working, etc.

I will more than likely throw a junkyard module in here as the car has 151,000 miles on it. I pulled the old module and pump out and got the part number on the module. The part number that comes up on Rock Auto for a new one for this car does not match whats in the car. the pump that is in it appears to be the original factory. I can not find either of the part numbers on a used one off of ebay but plenty of units that were on years that are close. As long as the plug matches and brake lines match up is there a big difference in these part numbers?

I'm assuming after putting it in it will have to be reprogrammed somewhere. Is this correct? And last but not least, is there a way to test my old pump just to see if that portion still works and can i use the same method to check the used one when i get it? Would appreciate tremendously if someone could shed some light on this. I really can't afford the price of a new module and pump. Thanks!!