535D M Sport seriously losing power

535D M Sport seriously losing power

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mogul

Original Poster:

15,011 posts

252 months

Thursday 7th February 2008
quotequote all
The car has been in the dealer today and they have diagnosed a faulty ecu (although they called it a DME?) and have ordered one form Germany which will take a week.

They have lent me a 3 series vert and from Monday a Z4M for the rest of the week, so not all bad news wink

Hopefully they aren't simply guesing here......

mogul

Original Poster:

15,011 posts

252 months

Tuesday 19th February 2008
quotequote all
Just to keep you all in the loop.

Got my car back yesterday and all fixed (hopefully) and the the problems were as follows:

8 days diagnosing and replacing/programming the ECU which I suspect was not faulty...

1 day diagnosing a faulty pressure sensor (?) which was showing as duff in the ECU read out.

1500 miles covered in their cars rather than mine whilst the work was being carried out smile

Dunk76

4,350 posts

216 months

Tuesday 19th February 2008
quotequote all
mogul said:
1 day diagnosing a faulty pressure sensor (?) which was showing as duff in the ECU read out.
MAP Sensor (Manifold Absolute Pressure)

Little pressure sensor that tells the ECU how much pressure exists in the inlet manifold (i.e. how much boost the turbo(s) have generated) and therefore how much additional fuelling is required.

If the MAP is faulty, the ECU will recognise that what the sensors either side are telling it (AMM, Lambda, and knock) do not correspond with what the MAP is reading. The ECU will also recognise when the sensor is operating outside of it's prescribed range.