[Biturbos4] Help with a few fault codes

[Quincy Chiang]

Hi everyone,

My car's been feeling slightly down on power lately, and the boost doesn't seem to be holding at 9 psi anymore (from boost gauge), more like 7-8 psi only.  So I was doing some data logging last night with a borrowed VAG-COM, but the results were somewhat inclusive.

When I stomp on the gas in 1st of 2nd gear, the requested boost would shoot up and the acutal boost would lag by quite a bit and doesn't get to the requested level.  But in 3rd gear, actual and requested boost seems to be on par.  Didn't do any logging in 4th or higher gears as I didn't need a speeding ticket.  I'll play around with it some more.

But here comes my question... while scanning for fault codes, I got the following two codes:

Engine
17965 - Charge Pressure Control: Positive Deviation
        P1557 - 35 - 10 --- Intermittent

Radio
65535 - Internal Control Module Memory Error
        00 - 00

Does anyone know what these are?  I suspect the first one has something to do with my wierd boost behaviour.  Thanks in advance for your help!!

Quincy
'01.5 S4
'90 CoupeQ