The engine always cuts out when the brake pedal is pressed or a brake light bulb is removed!

EPC & engine management warning lights are now on.

With brake light fuse removed, it is reluctant to start but will run ok except for a misfire when under full load at low engine revs.

You need to get the car scanned for fault codes

brake light switch at pedal is faulty. Also worth cleaning the throttle body. You have fluctuating revs on tick over?

Thanks to both above.

The faults codes are not accessible, as there is no communication with the ECU (via the OBD).

Connections to the engine ECU appear sound with no corrosion visible on any pins.

The engine idle is fairly consistent except it misses a beat approximately once every 2-3 seconds. It sometimes races (up to 2,000 rpm) when started, so it's probably worth a look at the throttle body.

Both the brake light switch and the throttle body cause these lights to appear, and both are common problems. The cost is a few pounds so worth a punt. Let us know how you get on. Next steps would be coils and plugs etc.

If it's likely that the ECU has a fault, is a repaired replacement a sensible option?

The following link claims to repair faulty units, but how do you know the problem is not elsewhere?

http://www.ecutesting.com/catalogue/product/skoda_fabia_ecu_engine_management_eem06033h.html

Thanks to both above.

The faults codes are not accessible, as there is no communication with the ECU (via the OBD).

Connections to the engine ECU appear sound with no corrosion visible on any pins.

The engine idle is fairly consistent except it misses a beat approximately once every 2-3 seconds. It sometimes races (up to 2,000 rpm) when started, so it's probably worth a look at the throttle body.

Is this using VCDS or VCDS lite or a generic code reader?

2 franchised Skoda dealers said they couldn't read the codes, with whatever kit they use.

Do you have an aftermarket radio?

see http://www.ross-tech.com/vag-com/aftermarket-radio.html

2 franchised Skoda dealers said they couldn't read the codes, with whatever kit they use.

That would suggest a problem with the ecu. Would be worth going to an independent specialist, skoda will just charge you silly money for a new ecu.

Do you have an aftermarket radio?

see http://www.ross-tech...rket-radio.html

You would have hoped that the dealer would have noticed that, but...

You would have hoped that the dealer would have noticed that, but...

I'm sure they will check that, fuse 3 (feeds the diagnostic socket), etc, if you pay them to investigate why they can't access the ECU :( 

Also worth cleaning the throttle body. You have fluctuating revs on tick over?

SWMBO's has fluctuating revs on idle. Do you have any more info on this please?

Thanks for all the above offerings.

The radio is standard OE, so unlikely to be the cause of the no comms.

I'll certainly get a quote from an independent VW Group specialist for the ECU replacement & reconfiguring. Franchised dealer quoted £550, which is why the aftermarket option is worth considering!

An independent VW Group specialist confirmed the ECU is permanently malfunctioning & advises that only franchised dealers can access (on-line) the necessary security code to configure a new ECU. This is linked to the vehicle immobiliser too, so a the key/lock set is required to match a used ECU from another car.

Not sure where that leaves the guys selling replacement ECUs!

It may be possible to repair the ecu rather than replace it.

Also depending on how old the car is you may have the immobiliser code and I think there are ways around it - I think Shark can do this (check in the sponsors section).