RomRaider

Its finally my time to contribute to this forum!

Description of issue:
I has e46 on m52b25tu with ms42, I swapped m54b30 with ms45.0
After swap I patched EWS using MS45 quickflash.
The issue was that the car cranks, works for 2 seconds and turns off like the ignition was suddenly turned off. I notices that it is a fuel relay, forced relay to turn on with ignition and car finally started and idled well.

But the Instrument cluster (Dashboard) was not showing rpms and temperature gauge was fully on the right in the red zone. I figured out that this is a CAN BUS issue by connecting to Instrument Cluster via INPA. ECU also had the set of errors:
0xCD87 PT-CAN communication error
0x2783 heated film at air mass measuring sensor
0x27D7 Ideal controller: position open
0x27D6 Ideal controller: position closed
0x296A Lambda sensors befor cat switched
0x29A7 O2-sensor before KAT Bank 1: signal
0x2883 mixture preparation bank2
0xCD9C telegram monitoring (speed, 1A0)
0xCDA5 telegram monitoring (status DSC, 19E)
0xCDA0 telegram monitoring (clamp status, 130)

I thought that i can ingore it, but while I was testing a car engine started misfiring heavily and another error appeared:
0x29B6 cylinder switch off
It caused an engine to work horribly as it was working on 1 or 2 cylinders. Issue dissapeared after simple action - turning engine off and back on.

In inpa I figured out the cause - type of error: "fuel level too low".
Ecu was disabling cylinders because it didn't receive fuel level, which is transfered by CAN BUS from the Instrument Cluster.

So I have uploaded a full and MCP from z4, which you can find in nearby topic, or you can use mine, but it was tuned a bit - e-thermostat values to open on 95, o2 disabled. Where I selected the "CAN Variant" - '0 - CAN11H'. Uploaded it to ms45 and CAN bus started working, tachometer started working, temperture guage started working, whole CAN BUS started working. So now ECU sees the fuel level and everything works as expected.

Overall - swap of ms45.0 is possible to e46 where ms42 was installed previously.