I had a call from a call from a tuning buddy from a workshop not co-located with me so I've not seen this vehicle or issue in person and he will be contacting support domestically (and then directly if they cannot help as the Aussie reseller) in the new week but I wanted to see if anyone else had ever seen anything like this.
The vehicle is an off road buggy with a 2006 L76 6.0 with DoD removed and small cam with a T400 to transfer case presumably (I haven't seen it).
Motor, ECM, TB and pedal assembly all from the donor vehicle - ECM was read, tune file was modified (to enhanced OS) Write Entire and all was going well until perhaps the 15th write calibration which completed successfully but instead of priming the fuel system as per normal, it sounded like the TB blade (or some other relay) was heard clicking and the only other difference was when the editor normally says "validating file" or similar after completing the write did not occur. Now the ECM "cannot be located, verify the vehicle is in run position" (or similar). My first advice was remove power from the ECM, disconnect and start again as E38s are remarkably resilient (especially since it was only write calibration). Upon trying this it was found that the buggy was wired with some sort of secondary power source. Even with this removed, the ECM could not be recovered by HPT or a colleague with EFILive. My advice was ECMs do occasionally fail (although rare) use the spare and check the wiring for correct voltages etc.
Second E38 goes in (same PN from 06-08 E38) and file is licensed and read, changes made and converted to EnhOS and Write Entire this time. Immediately upon completion, the "file validation" - I presume this is the checksum, not sure, does not occur. My advice this time is test the ECMs on a bench harness to remove the variables. Still cannot even connect to them with a variety of softwares or scan tools and both now appear dead. I recommend that it has to be wiring issue with the buggy so they go ahead and create an isolated and simplified harness for the ECM to ensure the secondary power for the ancillary systems is separate. Voltages checked and verified - move on.
Skip ahead to ECM number three which is again same part number from 08 vehicle, licence away, write entire a compatible manual OS (same OS as above) make changes to cal and all appears well for first few writes and thinking problem solved and will get this buggy to its competition that is now a day late for. Fine tuning some throttle follower settings and write calibration on what is now the third unique OS/Cal file (as they were all read out of the respective ECMs and modified to suit this vehicle not overwritten with the first OS in case there was some unknown changes or molestation in it somewhere) and again on a write calibration, it completes the write and skips the validation and relay clicks (or whatever that happens to be), ECM cannot be located and car obviously does't run.
Getting desperate now so onto the last spare (fourth) E38, change TB out in case there's some obscure issue there with incompatible TAC or something (grasping at straws), licence again and long story short is it fails.
So, six additional credits later and four E38 ECMs, he is quite in the hole, with this job now, both financially and reputation as a shop. Car will make comp using some friend of the owner's vehicle PCM with some canned tune (which I recommended against - but at least it goes) we are both starting to think the MPVI Interface is somehow causing a corruption of the NVRAM. It's worth noting that the interface is one of the early MPVIs and is some 9 years old (and the predecessor to the MPVI before that) I believe and must've written thousands of calibrations and hundreds of write entires on mainly P01/P59, but plenty of E38s as well without issue including other E38s the same day as the first failure (which is why the conclusion was to blame the wiring of the vehicle at first) I don't know. I don't know what version of 2.24 (it's about .9xx I think) he's running although I know it's pre-v118 firmware because neither he nor I were prepared to update based on issues I've read on here. Now he's not prepared to even test his interface on any vehicle in case that's the issue. I am sending him my MPVI so he can finish off the other jobs he has waiting.
My questions for the forum, pending what answers he gets from VCM Aust and probably support after that, are:
1. Has anyone ever seen anything like this before or have any suggestions?
2. Do you believe the seemingly fried ECMs are salvageable, and if so, how would you suggest one goes about it.
I have never come across any issue remotely like this before nor read about it and couldn't offer him any help. Ultimately, he just wants to recover the ECMs to try and recover some cost of credits and hardware and have a working and reliable tuning package to complete the outstanding jobs he has sitting in the shop. My interface should hopefully fill the void for the short term but I don't have unlimited E38 licence so even more credits will be required for this buggy and the other jobs waiting as they were licensed to his MPVI.
I can't answer all questions as I am not in same area but even for my own learning and experience I am pretty keen to solve this issue. Any help or suggestions are welcome.
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Originally Posted by schpenxel
