2003 BMW Z4 2.5i Crank, No Start Condition

Hey HPA,

Year/Make/Model: 2003 BMW Z4 2.5i

Engine: M54B25

Transmission: 5-speed manual Getrag S5D250G

Prior ECU: Siemens MS45.0 (Stock)

Current ECU: Siemens MS45.1 with EWS/Immobilizer bypass (Upgraded)

History/Context:

I have upgraded to a supercharged Vortech V3 setup, and have decided to move to wideband fuel management that the upgraded MS45.1 ECU provides (as opposed to narrowband that the stock ECU has). The car's wiring harness has been swapped to support the new ECU and wideband O2 sensors were fitted.

The car ran great for a few months with this MS45.1 ECU swap while I was working to dial in the tune.

Issue:

Tuner sent over a new tune file to update after we logged. When I was attempting to flash it, the cars voltage got too low (this was my fault for forgetting the battery charger). The tune failed to write. Result of this, caused the MS45.1 ECU to brick.

Not being able to fully communicate with the ECU or write to it, tuner sent a cloned ECU to try installing. This ECU is same, with same tune as the one that worked, however once installed, was getting 2894 -- Irreversible ECU Error, and car would crank, but no start. When clearing code, it would still come back. So we tried another cloned ECU just to see if we could replicate issue. Same thing.

Troubleshooting thus far:

With the MS45.1 ECU not working, we reverted back to MS45.0 ECU for troubleshooting. After resetting EWS/Immobilizer (which is only relevant to the MS45.0 ECU -- as the MS45.1 ECU I have has EWS bypassed), car fired right up. This rules out a lot of issues, but not certain where to go at this point. Any help would be appreciated, as I'd ideally love to be running the MS45.1 with wideband fuel management.

Thank you!