audi 80 avant M plate

[thepoynt]

new ecu fitted but problems with immobiliser. engine turns over and sparks but cuts out.

[mikes2]

why was the ecu replaced ? was it to fix the cutting out problem or was it for something else.

Immobilisers use a coil round the ignition barrel. with the key fitted, a signal from the coil is sent to the ECU.

If the ecu gets the correct value, the car runs fine. If it's wrong, the immobiliser will cut in.

The problem usually lies with either the key or the coil, not the ECU.