ECU Query

[Sqwidge]

I'd like to ask a question about ECU's, I understand what they do and I understand that usually they are coded and designed to work for only one car but I want to know about the things I don't understand about the ECU like can you just plug one from say a 1.2 16v into another 1.2 16v and would it work? To bypass the immobiliser could I just have the paired key hanging with my original keys so I wouldnt have to change the barrel etc? If ignition on effectively turning the immobiliser off could I not pull a fuse to unlock the ECU/immobiliser as I have done this on a Saxo in the past? As they dont have a stand alone power source why when you pull the leads to reset the fault light does it not reset the codes for the immobiliser?

I'm asking these as I may have to use a new ECU in the near future but thought it would be a good idea as I think they would be common questions but can't seem to find them knocking about.

 

[wull85]

i'm not entirely sure whether they are interchangeable but you can pick up a universal ecu for a fraction of the cost.my ecu went pear shaped a few years back and i was looking at roughly £400 to buy a oe replacement.instead i had fitted a universal ecu which cost me £150.hope this helps!!!

p.s:i say universal but i can't remember if it was called something else

 

[lewey]

I'd like to ask a question about ECU's, I understand what they do and I understand that usually they are coded and designed to work for only one car but I want to know about the things I don't understand about the ECU like can you just plug one from say a 1.2 16v into another 1.2 16v and would it work? To bypass the immobiliser could I just have the paired key hanging with my original keys so I wouldnt have to change the barrel etc? If ignition on effectively turning the immobiliser off could I not pull a fuse to unlock the ECU/immobiliser as I have done this on a Saxo in the past? As they dont have a stand alone power source why when you pull the leads to reset the fault light does it not reset the codes for the immobiliser?

I'm asking these as I may have to use a new ECU in the near future but thought it would be a good idea as I think they would be common questions but can't seem to find them knocking about.

The answers are on here, but in general people don't mess much with this stuff so the knowledge isn't there.

To help:
Engine ECU "pairs" with body ECU and code in key when new and car is first started. That engine ECU will now never work with another car or key. You cannot therefore interchange. To replace broken engine ECU, you must buy a NEW or "virgin" one. You cannot bypass the immobiliser using any of the tricks you mentioned. Only the key, body ECU and engine ECU are coded items, so the barrel or anything else you might be thinking of are generic electrically. You can't steal a car made after 1996 without the key, that is why car theft went down so much under Labour.

 

[lewey]

For clarity, if you have a problem with a body or engine ECU, often the cheapest solution is to buy a body ECU, engine ECU and matching key from a breakers and install the whole lot. Body ECU can be fiddly to change on some cars due to dash location.