2.0 turbo exec. engine management light

[Hangar18]

I've purchased a Peugeot 406 exec. Turbo. Its at 78000miles and is for all intensive purposes a bargain. On the tesr drive it lacked in pull and I'm pretty certain something electronic was preventing the Turbo from working. Sometimes when driving from cold the engine management light will turn off and I will actually get full Turbo pull from 2200rpm up to about 400prpm (noticeably) however- a lot of the time the engine management light is just on and the car drives really flat and n/a. It seems almost asif the engine temperature has an effect too. I can get the light out by cruising at 45in 5th for ten minutes and the temp will read 80 or less... any ideas on how I should go about trouble shooting this?

Little info about the car- I've had it 3 days, done quite a few miles (over 200) and there's no sounds or knocks apart from the alternator belt when the aircons on at low revs. The car pinged the original cambelt at 72k and it had over £1000 spent on it at the time- cambelt, head gasket, bolts and valves. Somebody obviously loved it. That was in 2009, done extremely few miles since and its due a service, so I think that might be my next port of call?

[mjb]

Someone with the correct (specialist) diagnostics equipment who knows how to use it will be pretty much guaranteed to be able to tell you what's wrong since it's linked to the EML light.

Otherwise I'm going to have a guess at the coolant temperature sensor, of which there are two on that engine - one for the dashboard gauge and another for the ECU.

[teamster1975]

I've got a very similar fault on mine, I believe it's related to the MAP sensor but sods law this is integral to the ECU.

[Hangar18]

That sounds great!
Whatever it is- the diagnostics machine doesn't want to get on with the ECU- so it's going to be a tricky job =/
the annoying thing about the car- is some days it will just work- until you come to a stop, turn it off - then run it from warm- really doesn't like that?

At this rate I'm probably going to end up selling the seats and alloys and weigh the car in. I can't justify paying the outrageous insurance for a slug

Is there any way of replacing the ECU cheaply?