6 cylinders. Big
AO Silver Member
Join Date: Jun 2009
Location: United Kingdom
County: West Midlands
It sounds to me very much like a clogged DPF.
I had this in my first 159.
Light came on when driving on the M5, limited power. Called my specialist and he confirmed a DPF issue. Switched the car off, left for 5 mins, restarted, and was fine until I asked for some power, then limp mode again.
The only was you rid this is to get it plugged into the computer at a specialist to do a forced regen, or, let the car do a regen itself. This is what happened to mine, a round trip to Torquay (from Brum) sorted the problem. I had limited power for most of the journey, each time I went to over take a truck the limp mode would kick in, it wouldn't rev over 3K or so. This is the ECU protecting the engine.
After a loooooonnngggg journey the car felt better, by the end of the journey all power had returned, but the EML light was still on. This turned itself off after 4/5 starts.
With limp mode (if it is a DPF, sounds like it) the car needs to be hot for an extended time. The ECU will run through the process of a regeneration during this time.
Sounds like during the second longer journey the car failed to do a regen, maybe you dropped speed or turned off mid regen?
Moved over to the dark side
And loving it