153 ECU's

[Heresy_Act]

I've tried running it for it to get better, as suggested, but it's still not running on its own.

I feel like adjusting the idle such that it'll actually idle with this computer, but I know that's the wrong way to go about it.

Think the stealership will get it working for me? :P

[fporro]

maybe it's a bad # 173

has it ever been open ?
if so, it is possible that the chip was reinstalled backwards as it fits both ways.

I have a few stock # 173 chips laying around if you need one.

do the following ...

ignition switch to ON position (car not running)
pump gas pedal 5 times
watch Engine (far left side, red) light for ecu fault codes. four digit codes as seen here ...

http://www.unofficialbmw.com/repair_faqs/motronic.html

[lordofthewaters]

Back in the day I had a 153 ECU. I tried swapping for a 173 but the car did not run...well it did, just not very well.

Some claim it is a direct swap, but I have seen others claim that you needed to rework the wiring harness. Hell, I think I even saw an article about reworking the harness for a 153 to 173 swap at one point.

I eventually gave up and kept the 153 until I swapped engines.

The 173 box was used as a warranty replacement for cars with the 153 computer. So I can see no reason why it isn't a direct swap. I think it went from firmware 1.1 to 1.3 with the 173 too.