Roomster 1.4 tdi engine management light on and also heater plug light flashing

Hi all.

my first post

i have recently had my engine rebuilt on my 2009 model skoda roomster 1400 tdi after snapping its oilpump chain but after engine has been put back in and started the garage who have done the rebuild have now said there is a fault which is engine management light on and also glow plug light constantly flashing.

The garage who have done the work on the engine are engine specialists who do . Crank rebuilds,head skimming,mainly engine work so they are now saying it has an electrical wiring fault of which I'm a bit hesitant to believe.

i haven't got the car off them yet as I said if it is a electrical fault could they take to an auto electrician of which they said they would but this is not until the end of this week.

im sure the guy said to me low vacuum pressure-would this make sense.

could it be something as simple as a maf sensor gone faulty of crankshaft/camshaft sensor faulty or bad connection as with engine being comletelty apart I'm guessing all these leads have been unplugged.

any help much appreciated.