bmw m3 needs new engine wiring loom and ecu have a 2nd hand 1 wen fited will it work or need programing?
December 9th, 2009 | by admin |engine loom caught fire so when i fit everything will the car run or will the ecu have to be reprogramed even tho its from the same make and model bmw e36 m3
This is a tricky question. The 2nd hand wire loom and ECU from the same model is obviously going to wire in the same. It is questionable whether the ECU will perform correctly when all entities have been connected however.
Even though it came from the same type of vehicle it carries some very specific data about the vehicle it was in. It’s hard to give an accurate answer without knowing the year of the vehicle but chances are high that it will fail without being programmed or "reset" by a BMW tech.
Many of the newer ECU modules in a BMW are embedded with a physical hardware address (much like a MAC address on a personal computer), this address much match up with other components in the vehicle or the ECU will refuse to work.
In this situation I would go ahead and replace the entire loom and install the new ECU. Once it is completely installed give in to the urge to start it and see what happens…you might get lucky. If you notice any strange behavior it will have to be serviced by a BMW tech. BMW’s were never intended to be worked on by non-certified techs….they’re now actually engineered to prevent this!
Hope this helps!
One Response to “bmw m3 needs new engine wiring loom and ecu have a 2nd hand 1 wen fited will it work or need programing?”
By mrharris32 on Dec 9, 2009 | Reply
This is a tricky question. The 2nd hand wire loom and ECU from the same model is obviously going to wire in the same. It is questionable whether the ECU will perform correctly when all entities have been connected however.
Even though it came from the same type of vehicle it carries some very specific data about the vehicle it was in. It’s hard to give an accurate answer without knowing the year of the vehicle but chances are high that it will fail without being programmed or "reset" by a BMW tech.
Many of the newer ECU modules in a BMW are embedded with a physical hardware address (much like a MAC address on a personal computer), this address much match up with other components in the vehicle or the ECU will refuse to work.
In this situation I would go ahead and replace the entire loom and install the new ECU. Once it is completely installed give in to the urge to start it and see what happens…you might get lucky. If you notice any strange behavior it will have to be serviced by a BMW tech. BMW’s were never intended to be worked on by non-certified techs….they’re now actually engineered to prevent this!
Hope this helps!
References :
After Hours Automotive – (User Owned Restoration Shop)