New ECU

Post Sat May 09, 2015 1:36 pm

Guys I'm installing a brand new motronic ECU on my 1990 320i..

All codes on both ECU's match..

However the engine won't start with the new one in. I've swapped them over 3 times now, and always turns over and runs on the old one but not the new one. Is there something I'm doing wrong here, or is it a duff unit.

Post Sat May 09, 2015 2:17 pm

Engine 'turning over' is nothing to do with the ECU.

Post Sat May 09, 2015 2:23 pm

Brianmoooore wrote:Engine 'turning over' is nothing to do with the ECU.

Sorry, starting!

Post Sat May 09, 2015 2:56 pm

You said "Brand new". Is it really new from the dealer? They come uncoded. They need, with the unit installed into the car, to be programmed via BMW DIS.

Post Sat May 09, 2015 3:13 pm

What you could do is remove the EPROM chip from your old ECU and fit it into the new one.

Why are you changing the ECU anyway?

Post Sat May 09, 2015 3:19 pm

I thought the programming issue might bite me on the arse.. and I'm guessing that's it then. I thought perhaps because it's a like for like swap I may get away with it.

Changing the ECU because of idling issues.. pretty much every other cause has been explored other than the actual DME being at fault... managed to get a brand new one pretty much dirt cheap from Germany so thought it'd be a good opportunity to get that sorted.

Can they only be programmed at the dealers alone?

Post Sat May 09, 2015 3:41 pm

It can be programmed with BMW DIS and a ADS interface... As for the interface, you can get it from a seller from USA in eBay, search for BMW TinyADS cable. You will need a laptop with a real serial port or with a ExpressCard slot and a REAL RS232 to PCMCIA converter. As for the software, ahem, in theory it's only available to dealers, ahem...

Post Sat May 09, 2015 3:50 pm

I can program you a chip with either the standard program, or Mild/Wild versions.