James Culbert’s query about post-mot testing with his Nissan NV200 Combi (‘Limp-home mode’, Diagnostics
Doctor, May 2018) jogged my memory. I had a similar issue with my 2007 BMW E70 X5 3.0 when I collected it from an MOT test. Within about five miles on the A14, it lost all power and coasted to the hard shoulder. I shut it down, but it was fine when restarted. No warning lights, no codes, nothing.
Then, after the last MOT, it did exactly the same thing on the A6 near Leicester, dying without warning within five miles of passing the test with no advisories.
Thankfully, it hasn’t repeated the failure between tests, so I can only put it down to the test procedure. I suspect the extreme throttle tests carried out on diesels is stressing and upsetting the system, but it would be interesting to get a definitive diagnosis.