Glow Plug Light

Hi and apologies if it's been asked before.

Driving on the motorway earlier, lost power and a few seconds later the glow plug light was flashing.  Also 'Start-Stop Error' showed on the display.   Was able to get off the motorway and get home safely.  

Called the RAC today and they were unable to get out to my location so they sent a sub-contractor out on their behalf but they just recovered the car.  The guy reckons it could be injector fault?.....I have no knowledge on these things.  I suppose the only way is to get a diagnostic reader.  Basically a rough idea of what to expect and approx costs to fix?

Thanks in advance   I'm in a 2014 Rapid 90bhp 

p.s. When I checked the car a short time ago the heat plug light was not flashing

Edited 27 October, 20205 yr by kevvrs_130