RomRaider

Hi I'm hoping someone can help me.. I have done the conversion from MS41.0 to MS41.2 on my EURO e36 328i. As most know, the car only has two primary lambda sensors, no post cat sensors.

The conversion went smoothly, on a spare ECU I have (it's actually my slave ECU for emulating these on the dyno, so the chip is on a socket, and easy to reflash if it becomes 'bricked).



The car works fine, as it did before, as long as it's not in 'closed loop', either with the lambda sensors unplugged or when an emissions related DTC is present. With the lambdas plugged in, I get the codes for lambda sensor heaters, immediately - and they won't clear.



If I remove this DTC, the car will then try and go into closed loop mode - and the lambda integrators go crazy trying to richen up, i.e. they think the car is lean. It's definitely not, as I have a wideband in the back and I'm in a controlled environment on the dyno. Eventually, after going very rich, it throws the inevitable DTCs



I think the car cannot see primary sensors, possibly due to the MS41.2 system usually running 2x primary and 2x post cat lambda sensors, but I see no-one else having this problem on the forum...

I've included a copy of the full flash I made, and then the (very useful) MS41.0 ID41 conversion partial.




Has anyone seen this before?

Thanks in advance.

James

I assume no-one has seen this before then?

I'm going to get back to it today... see if I can't unpick some of the data early on in the full flash, and find the lambda characteristic curve... I suspect there will be some stuff about physical lambda sensor connection / which pins etc around there.

Thanks

sounds like you have the o2 sensors switched banks pre-cat.
post a log file.

What would you like me to log? Like I say, if I leave the code enabled for lambda heater errors; it just runs in open loop failsafe.

JP

you need to log it where your o2 sensors "go crazy".
I bet you have the pre-cat o2 sensors switched

Hi,

Found the issue in the end... for some reason, my car (OBD1) uses the inputs on the ECU which are defined as 'post cat' on OBD2 (MS41.2)... After some messing, I've found the pin assignment earlier in the file and has swapped this.

Runs fine now!

Thanks

have you bought a ms41.2 spare ecu or was it a 41.0 on which you put the 41.2 soft?

Hi,

I have both... MS41.0 upgraded, and genuine MS41.2 which I bought from the states.

Thanks

Currently, I have turned off the second probe due to the use of another exhaust manifold. I would like to use the second probe input to log in another parameter. Unfortunately, the integrators show that they work to some extent for the other bank. Have any of you tried to use the other probe's input for other purposes? Conversion to MS41.2 made.