Dont think the dash would come on without the immobiliser. What year and model is it?

I thought the red flashing light was the immobiliser? Does the steering lock come off because that is what switches off the immobiliser? The yellow engine light is on so I would expect it to have some fault codes.

What actually does work? Does the steering unlock and the dash light up? If so have you tried scanning for codes?

Have you tried resetting it?

As Nodges says jiggle the steering as you put the key fob in. Until the steering unlocks nothing else will work.

Is the steering lock on?

It should have a fluid change at 10 years or 150k. But you haven’t said the age?

Sounds like torque converter shudder. Mine had it for several years and it never got any worse. Might be worth changing your transmission fluid and if that doesn’t sort it had a bit of Dr tranny shudder fix.

Not necessarily, it could be a whole host of different things. Perhaps Haldex is low on fluid, the pump has failed, the control unit is not getting a signal? Or many other. You really need to ascertain the fault before taking the plunge.

Loaded or unloaded should not make much difference on a level road at a constant speed. Turbo either works or not (I wouldn’t change one just to save fuel). Drag goes up with speed and things you put outside of the vehicle like roof box, bike carriers, trailer etc. DPF goes through a cleaning...

Just add I tried changing to expensive diesel and it made very little difference

Sounds about right with a big trailer and a roof box. I drive to Spain quite often and on the toll roads at steady 65mph, 30 °C ish, Spanish diesel and no trailer etc. then get 35-38 mpg. But at home round town, in the winter on supermarket diesel I am lucky to get 23 mpg. So rounding up they...

Not come across it myself but could it be struggling to read the satnav disk under the drivers seat? perhaps give it a wipe? remember center to outside not round the disk.

Sounds like you bought a load of gear to get round a problem instead of fixing it. So many things tampered with I wouldn’t know where to start.

Two giant schnauzers fit in but they have to get on. As one got older, I tipped the rear seat bases forward and put his bed across so that he didn’t have to jump up and down as high.

Walk away

I did this for FL2 but might give you some ideas, good luck.

Nearer 1 ohm I would have thought?

Under the power steering reservoir

It’s behind the drivers side headlight. I would just link it out with wire