Sure you can test it. Just find a shop which has the RARE Toyota TCCS test computer.... A suitcase with a dozen adapters and simulates a running vehicle. The TCCS ECUs are VERY robust. Aside from leaking capacitors or moisture damage they rarely fail.
And... WOW, that car is a nightmare (see: perfectly normal MKIII
).
The TCCS tester looks much like this (but this isn't it):
As common as the N/A MKIII is, I'd look for someone who's got one in your area and give 'em $20 to let you try theirs in your car for an hour. They're very commong.... I think I've got a couple buried in storage somewhere (probably being use to keep one of my chests of deisel tools off the ground :P ).