upgrade ecu

[8565]

Hi all,

i converted my motronic 1.0 to 1.1 on my 1986 325i chrome bumper
. but i thinking to upgrade from my current 1.1 to 1.3. just wondering which 1.3 motronic is suitable for my car, is 0261 200 164 or 0261 200 380 ? by the way my car is a auto.

[Brianmoooore]

All the M1.3 2.5 ECUs are interchangeable. The successive versions are just upgrades* as technology advanced over the life of the system.

*Latest is not necessarily best. The 173 is the version of choice.

[Speedtouch]

Beware, however - earlier M1.3 ECUs such as the 164 have two PCBs and are difficult to get upgrade EPROM chips for; you are best sticking with the later and more reliable (single PCB) M1.3 six-pot ECUs which include 172/173/179 and even later 380/381, which have extra diodes in the idle control circuit (which are known to occasionally fail).

All are essentially identical, apart from the program on the EPROM chip.