Hi All.

There are several posts about the ABS Module and repairing the broken solder joints. Here I want to discuss the rest of the module!

To make a long story short, I pulled mine off today, and the back side of it looks like it has seen much better days! A good bit of corrosion and rust on the plugs on the back. Is this reason for concern?

 

Looks like a well worn normal JLM21323 ABS module to me.
They are prone to the 'faulty solder joint' problem.

 

But it's fine to resolder the connections and reinstall?

 

The "corrosion" seen is just rust residue from something corroded on the other side of the ABS. The 9 "plugs" are solenoids, coils imbedded under the blue plastic, that activate the valves in the valve block. As longs as the solenoids inside are good, any dirt outside will not affect them. You can just clean/brush it off. The concern here is whether the solders on the PC board inside the module are good. Most common failure are the big solders on the two large pins that provide power to the ABS pump. One way how these can be re-soldered without cutting the box open: