Intercooler coolant pump drain and replacement

[itzjoker]

Couple questions:

Anyone know which line I should be disconnecting to drain the coolant for intercoolers? I believe the coolant is separate from the turbo/engine coolant.

My intercooler pump needs to be replaced. I'm getting code 20A202 (reduced power charge air cooling). I was under assumption that the pump was still working but not effectively since voltage is low. Is the "reduced power" referring to actually losing HP as well? I believe IAT's are measured at the MAF, does anyone know how to measure charge air temperatures using bm3 and normal temps?

Does anyone know how to run ISTA tests on the aux pump to confirm that it actually needs replacement?

Thanks