[SOLVED] - 2006 Toyota Sienna ABS Diagnosis (C0226 & C0256)

UPDATE
I got a used ABS module from Ebay.  After getting it on (which is a real pain on these Siennas), the ABS light did not return after several drive cycles.
Scanning the car revealed no ABS codes.  That's a fix.  Thank you for the tips!

So I'm working with an 06 Toyota Sienna, and the ABS light and Brake light are on.
A little while ago, I pulled codes from the ABS module, and I had a C0256 'Hydraulic brake booster solenoid circuit open or short (SRL)'.
The lights would come on periodically, and I would sometimes hear the *ping* noise when the car ran the ABS test, and sometimes I wouldn't.
Flash forward to today: the 2 lights are always coming on every time the car is driven, and when I pulled the codes again, I got the C0256 code, and  a C0226 'Hydraulic brake booster solenoid circuit open or short (SFR).
It seems the official Toyota wiring diagrams treat the ABS solenoids and pump as a black box, as they are not shown on their diagrams.

I found a non official incomplete diagram of the ABS ECU from a training website, and it looks like this:
 

I highlighted the solenoid and motor portion of the module in red.

At first, I was thinking I would hook up my oscilloscope to the module and actuate each solenoid with my scan tool to see if I could determine if it was the unit that was bad, or the wiring harness.  But after looking at that layout, it seems that the solenoids get power in series through the ABS relay, and are individually ground-side switched through the ABS module.  So if there was an issue with power supply, it would affect all the solenoids, and not only a few.  Same with the ground.  Since they all share a common ground after the ABS ECU, a problem in the wiring harness would knock out all the solenoids.
Therefore the issue must be within the ABS module itself, right? 

This is assuming the diagram I posted is correct for the 2nd Generation Sienna.
Is this diagram mostly correct for my situation?  If it is, does my logic make sense that the problem has to be within the unit itself in order to have only a few solenoids shorted?

Much appreciated.

Therefore the issue must be within the ABS module itself, right? 

I would tend to agree. Just for that 110% feel-good confidence, you could load test the module powers and grounds. Eyeball the connector for corrosion and spread pins. None of those things should cause your faults, but modules do strange things everyday.

Otherwise, its ABS assembly time! If it helps, service info doesn't indicate that programming is necessary, just a Zero Point Calibration. That means you can probably get away with a used part.

Thanks for the confirmation.

I plan on looking at the contacts of the harness as well as check the wiring for any possible damage.

After doing some more research, I realized that these ABS component systems are pretty modular.  I guess they designed them that way so you don't have to bleed the brake system each time something needs to be replaced.

I was thinking about going with a used system, as Toyota will only sell the module with the pump and hydraulic block for a king's ransom.

I've got an Autel Maxidas DS808.  I might be able to run the ZPC in the service functions.  Need to check.