ECU Woes

Further on from chasing the intermittent cutting out after restarting the car I thought it was probably time to take the ECU out for a look. I am aware that the outside of the ECU was clearly water damaged and it has taken me this long to realise that they probably aren’t as watertight as they are supposed to be.

Suspecting that there might have been some damage to the ECU inside the case I started taking it apart.

Once I had the cover apart, my suspicions were confirmed, the ECU has certainly been swimming. There is evidence that the car has had a coolant leak at some point in the footwell, probably from the heater pipes. Add this to the fact that a previous owner had clearly been storing the car outside in all weathers for the other corrosion I have found previously on electrical parts, I suppose this is just to be expected.

You can see green corrosion to the pins in several places here.

I cannot be sure how full the ECU housing has been looking at this picture it is possible that it has been quite full.

It is unlikely that this is a multi layer board, so I suspect any damage is to the surface mount components on either side, both sides are showing signs of corrosion however.

I am not happy fault finding without replacing this, clearly it has been quite wet at some point and I can no longer be sure that the fault lies anywhere else. Even if I get another ECU for the purposes of fault finding and the fault remains, I need to rule this out.

I will start hunting for a spare ECU…