ECU #153

[cyrmanj]

No. 153 chips work ony in 153 dmes. The 380 can use 173 chips and vice versa however.

Thanks for the answer.

Excuse my ignorance: 380 ECU is a newer version of 173 used in 325i, 325is and 325ix? If that is true, then if I have a 153 ECU on my 325i can I upgrade to the 380 as easily as with a 173?

What are the main differences between 173 and 380 ECU's?

Also, do you know if there are different settings for euro and US ECU's?

Sorry for asking too many questions, trying to learn from the people who knows! ;)

[everlast]

IIRC the 380 ECU should work in place of any 173, so yes, it should work on your car that has a 153.

However, the chip inside the ECU is not the same as a 173, so you limit your upgrade path to a high octane chip, etc, if that matters to you. Hope this helps.

[lordofthewaters]

IIRC the 380 ECU should work in place of any 173, so yes, it should work on your car that has a 153.

However, the chip inside the ECU is not the same as a 173, so you limit your upgrade path to a high octane chip, etc, if that matters to you. Hope this helps.

You can use any chip designed for a 173 ecu in a 380 ecu.

[cyrmanj]

You can use any chip designed for a 173 ecu in a 380 ecu.

Good!, then what are the differences between 173 and 380? Tighter emissions, smoother idling/acceleration, best fuel consumption?

Thanks for the answers guys!

[everlast]

You can use any chip designed for a 173 ecu in a 380 ecu.

Cool, great to know, thanks for the clarification. I had been going on the assumption they were different as I'd seen 380 ECU chips for sale that didn't specify 173 compatibility, but that was probably from an ebay know-nothing-seller. :D

[cyrmanj]

From BMW digest:

The "153" Motronic unit came on the 87 325i/is and the 88 325i/is
up till build date 2/88, then from build date 3/88 the newer improved
"173" unit was used. These two are interchangeable but the 173
supposedly has a better idle circuit.

[Wh33lhop]

Wow. So the 173 is a straight up swap with the 153? I've got an 87 325i, it idles like horse piss, the whole car shakes (to be fair it's got a vacuum leak somewhere),and sometimes it will take a good 3 or 4 seconds straight of cranking before it fires up. I figured I'd have to add in some sensors and swap main harnesses for a conversion but if I can just swap ECUs then I'm down. Maybe put a mark d chip in there while I'm at it...

[everlast]

Well, the 173 sure won't cure those symptoms, but it might help sort them out via the stop test.

If the problem is all vacuum leak, though, it won't help at all.

[lordofthewaters]

Good!, then what are the differences between 173 and 380? Tighter emissions, smoother idling/acceleration, best fuel consumption?

Thanks for the answers guys!

My 380 idles smoother than my 173. That's the only difference that I've personally noticed.

[everlast]

Huh?

[cyrmanj]

Well, the 173 sure won't cure those symptoms, but it might help sort them out via the stop test.

If the problem is all vacuum leak, though, it won't help at all.

+ 1

Sorry to deviate from the topic, but I had issues with idle on my 87 325i and it turns out to be bad hose (causing a vacuum leak) and the throtle body needed some minor repair.

However a 173 ECU upgrade won't hurt! ;)

That's the only difference that I've personally noticed.

Thx for the answer.

[weaksauce]

No. 153 chips work ony in 153 dmes. The 380 can use 173 chips and vice versa however.

if i was given a chip by a friend and it is for a 89 M20, which DME is it for?
I have a 153 in the car, but i also have a 173 in the garage tht i was going to swap in.

[nando]

if i was given a chip by a friend and it is for a 89 M20, which DME is it for?
I have a 153 in the car, but i also have a 173 in the garage tht i was going to swap in.

Motronic 1.3 ECUs aren't really specific to years, so it could be anything after 173. There are also other versions than 173, 380, etc. I compared a 525 and 173 side by side, they are exactly the same, it's probably just a few bytes of code inside the CPU that are different. They are all compatible with each other though, as long as it's a motronic 1.3 ecu.

[Wh33lhop]

Just an update (yes I know it's 4 in the morning), I solved the vacuum leak but the idle issue was still there. I picked up a 173 ECU yesterday and it's gone.

HOWEVER.

The car definitely does not pull as hard, even after a day of flogging it. The 153 had been detonating recently when I ran 87 so after adjusting the valves I bumped it up to 91 to see what it could do. It gradually started pulling harder and harder, I was pretty impressed by the little M20 in the last few days. However when running the same grade with the 173 it was an instant downgrade. That is to be expected since it's still "learning" my M20 and adjusting timing and fuel maps, but it still hasn't gotten to the point where the 153 was. The plans for the 173 include a mark d and injectors so I'm not too worried, but it's interesting. I read somewhere that some of the Spec E30 guys see better power with the 153 DME, and after this experience I'd be inclined to believe them.

[nando]

Motronic isn't capable of adjusting timing maps. All it can do is adjust fuel with a single variable that affects all the VE maps.