Not used van for a couple of weeks so decided to run it yesterday. Driven about 40 miles half rural half city. Also filled up with premium diesel from a rural filling station. This morning set of again in van and coil light was flashing. Drove 30 mile to work mixture city and rural, light still flashing also stop start not working. Drove home tonight no flashing light but stop start still not working. Never had this in over two years. Any ideas. Could fuel have been old? Could 2 week not running have done it? Never had a regeneration light come on and had van from new. Always similar sort of driving although we have not been for a big run for a while.