2005 S80 Troublecode 6805

[LoudHoward]

Hi,

sorry for my bad English. I come from Germany.

I have an Volvo S80 build in 2005 an MY06 D5 engine.
I got last week first time the limp mode. It was cold start an I want drive on highway. I drove 80 Kmh.
So I turned back an drove to my Volvo dealer. It told me that I should drive highway to blast free my turbo.
So i drove 200 km on highway. Back to the dealer they read out the code. ECM 6805. They read the pressure o. The front bottom engine mount. It hold the pressure.

Now the limp mode come every time when I drive faster then 80.
Today I decide I drive to another Volvo dealer. Limp mode on after 3 km limp mode off and no problems anymore. They read trouble codes. 6805 again. Then they told me they plug off the hose to the endings mounts. I should drive and tell the, if trouble codes come back. Back on the highway limp mode on and goes not off. Engine run worse. I returned to Volvo dealer and told them error is back. They should plug in all hoses. They did It but engine runs hardly. The limp mode goes not off anymore. So back at home I plug off all hose and plug in again. Test drive first 15 km fine. 120kmh and no problems. Then after 15 km limp mode on. Put engine off and on drive a little faster limp mode on.

No black smoke. So what can I check at home alone? It would be nice for every answer.

Regards Christopher.