I have a friend that is getting a P0740 and P0700 codes from his ECM.

p0740=torque converter clutch control circuit
p0700=internal trans controller

I haven't pulled the codes directly from the TCM but is there any advice on what to look for or might be common on these vans?

I would love to think I it would be as simple as a new lockup solenoid but I am never lucky enough to have a simple to do repair unless the part is $5000 dollars.

trans is dying... dan

The trans seems to be acting fine 99.9% of the time. My concern is that I have read posts on the internet from people who had the trans rebuilt, replaced the TCM, solenoid packs, input/output speed sensors etc and none seemed to be the silver bullet to fix it. Still the problems persisted.

Obviously they had bad mechanics but I am calling on the awesome wisdom and powers of the Moparts Guru's to intercede on this cars behalf.

any time you get a P07XX code, the PCM will throw the P0700 code.
Get a wiring diagram and check all the wiring for the TCC, especially the connectors and in the fluid.