Motronic 173 and 179

[lovnbmws]

What are the internal or programming differences between the Motronic 173 and 179. 173 is form an m20b25, 179 is form m30b35. Both are Motronic 1.3 units. Do they use the same plug? Could one be substituted for the other with the changing of the chip? What are advantages/disadvantages if it is possible?

[rs4pro3]

179 is made to run a litter larger engine I think it would run like shit with the 173. Yes the plug is the same as I said in an email to you(I have both ecu's and harness sitting in my room). It would be interesteing to compare the maps, guys have found out you can actualy use an eta ecu on the 3.3 m30's and have a custom higher redline chip made. Some one compared the maps and found they were identical, except for the revlimter.
The 179 also has a few features the 173 dosn't, like a variable TPS(on the auto models), DWA antitheft system, and a few others, plus a larger AFM(which some have found can be plugged right into a 325i with thr 173 ecu.
It would be interesting to try if you had a motor you didn't care about.

[lovnbmws]

Ok, the 179 and 173 plugs are the same… the 179 dose has more options but I’m not going to use any of them in my application so that shouldn’t matter. I would assume the difference between running a larger engine vs a smaller engine would be the fuel map… easily changed with a performance chip. So I’m trying to figure out why I can’t plug a Motronic 173 into a b35 harness using a 179 OEM or JimC chip. Theoretically the only thing missing would be the extra fluff options found on the 5 and 7 series of which I have no leads for anyway.

What am I over looking? :roll:

[lovnbmws]

I just got done cross referencing my eBay collection of pdf schematics for the e30 against a Bentley manual DEM pin assignment table for an e34 535i. Every pin matches exactly except for pin 23. Bentley says it’s supposed to be vacant but the e30 uses it as an output for the “oxygen sensor heater relay”… just figured out the o2 sensor heater relay on a 535i is supplied power via the fuel pump relay. So I jump power over from the other relay and every thing works out fine. Now I just need to compare fuel maps… :P

[rs4pro3]

Ya just compare the fuel maps, Maybe contact Mark D. who burns custom chips and see if he has base maps for both. Seriosly though if you look on ebay Vine's automotive in Alabama has 179 ecu's up there for $40 quite often highest I've seen on sell is $60