OBD Code P01A4 - 2.2 CRD Cruiser

Hi, can anyone tell me what this code would mean? I've only just brought this Cruiser 2.2 CRD as a second car, and am struggling to find out what is wrong with it and why the OBD light is on. Its been hooked up to a Diag Machine and this is the code displayed, thanks for any help given.

How does the car drive (can you feel the turbo come in, go on boost) can you hear and hissing when you rev the car. the code is a chrysler only code, but I have found it is linked to the intake/fueling.
First thing I would go for is the turbo inlet pipes. To test, take the engine cover off (2 nuts at the back of the engine, then look at the front of the engine, you will just see a pipe looks like a radiator hose about 2 inches in diameter. Put your hands down between the radaitor and engine and have a feel around this pipe. If your hand come out wet with dirty oil, you have a leaking or spilt turbo pipe. ( Common problem, I've now changed 7!!!
If not, try the bottom hose, jack the car up and look for a similar hose at underneth the turbo, this as been known to leak either from a split or just a loose clip