Engine Warning Light - D4d Pre Heaters Failed ?

[SiJul]

Hi

Any advice appreciated.

Engine warning light came on on my 2005 90000 mile D4D probably (but not precisely sure when) after a failed start (it started second time) having been left parked in temps down to minus 15 deg C for a week up a mountain in France.

My local Mr T has since interrogated the cause of light illumination and suggests I have new pre heaters 'as that is what the code that came up usually indicates'. However, the warning light now remains off after being reset and the starting in more normal frosty mornings is perfect. All other running parameters (performance, mpg, starting, oil consumption etc etc) are just fine. Unfortunately I did not get told which message had been stored.

So, is it likely that a failed start (or two) could cause engine light to come on and stay on? If light now stays off can I put off pre heater renewal until they really die/starting is too difficult?