Hello,

I am the owner of a Freelander 2, 2009, 2.2TD4 SE, 152 HP, automatic. I'm facing a problem that no one can deal with, namely, P0299(00) - Turbo/Super Charger underboost / low boost which appears as an intermittent error approximately 50km after it was deleted, and after about 4-500 km, the check engine lights up. This is happening during summer. Intresting is that during colder weather ( winter for example), the error appears after 3-400 km as intermitent and check engine light up at around 1000kms.
No other errors are present except that one.
It should be mentioned that the car has absolutely no symptoms when the error occurs, either intermittently or permanently with the check engine on. It shoots normally and constantly, it does not emit smoke, there are no strange sounds, it does not consume oil, it does not have a high fuel consumption, it does not jerk.
After several visits to several services, I changed the following: Throttle valve, Pressure sensor, flow meter, reconditioned turbine and checked actuator, reconditioned injectors, diesel flow check, smoke intake check. A road test was also carried out, monitoring the turbo pressure, which was fine according to the mechanic. I even went to the dealership office, where the diagnosis revealed that the actuator was defective. I went again with the actuator to have it checked at a company that deals with reconditioning, but they told me that the actuator has no problems after being tested with a device, and if it had, it should have given an error on the actuator. I am attaching an image below with the values that appear in the freeze-frame when the check engine is turned on, maybe they are useful.
Also, the software was checked and it is the original one.

Please advice what can I check further, without spending a fortune without solving this

Thanks in advance

After having my turbo changed I started getting underboost AND over boost warnings but I don't remember symptoms just the warning popping up.
The garage was originally blaming pin holes in the pipework around the turbo (sorry I'm not that technical)
After changing the pipework and the fault persisting they called in a LR technician, my problem turned out to be a faulty 'new' turbo.

First check is for holes or leaks in the boost hoses/pipes. 2009 Rimini Red SE TD4. Soon to be sold.
Hyundai Ionic 5 Ultimate on order.
Gone. 2006 Tonga Green i6 HSE.

MAP readings are good. The car is working fine. Those codes are fake as long as you dont feel any power. loss. Stop throwing money Check boost pressure sensor electric circuit, see that the wires has intact isolation and if one of them does not touch the metal or other wire somewhere from time to time.The whole run, from sensor to the ECM. I had a similar problem dor eight month I was looking for a solution, and I found a intermitent short circuit between two wires in a loom of 12 wires run.