2009 (B6?) Passat Estate 2.0L tdi Highline Plus - lack of power, flashing warming coil lamp, limp mode

[davies63]

Hi all, first post here.

My 2009 (B6?) Passat Estate 2.0L tdi Highline Plus has recently developed the apparently not-uncommon ‘lack of power, flashing warming coil lamp, limp mode’ problem when (a) going up hills and (b) after a stretch on a motorway at 70mph. It resets after ignition on/off but comes back again next trip.

The car is due to go on the tester this Wednesday and I appreciate more educated opinions can’t be shared until the results of that are in but, after reading the historic posts on here, I’m assuming it’s an underboost issue, although I've also read it could be overboost.

From the helpful replies previously, it would appear that it could be any one (or more!) of the following things:
• Actuator – split diaphragm, no vacuum
• Sticky/seized turbo vanes
• Pressure leak in hoses/pipes
• N75 valve
• MAF sensor
• EGR valve

Two tentative questions for post-diagnostic test:

1 Will the test results specify which of the above issues it is or will they just point in the general direction?
2 Short of changing the relevant part in the above list, is there an in-situ clean (such as a carbon clean or a DPF clean) that could/would work?

The wife has just bought us a caravan (very nice of her!) but I’ll obviously need to get the engine sorted before we start towing anything heavier than a pea.
Cheers,
Kim