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View Full Version : e38 possible bad ecm?


ls1mike
May 17th, 2013, 06:35 AM
Hey guys been really chasing our tails with this one - been having many weird phantom issues with this vehicle, so many problems not even worth mentioning because if you can imagine a problem it is happening.

Biggest single factor in making me think it is a computer issue is that the car will run idle and work great then shut it off try to start it back up and it will not even run at all. This behavior is intermittent sometimes it will run for an hour and I will work on the tuning then sometimes I have to load several tunes into it to idle.

Who here has run into a bad e38 computer - what was it doing? Can I use any E38 as a replacement?

As far as what the tune is doing I have tried pretty much everything, I have a lot of experience with these but almost a week of diagnostics and tuning into this thing so I'm running out of possibilities.

Thanks, Mike
ScarabEpic22
May 17th, 2013, 07:17 AM
It happens every once in a while.

You cant just use whatever ECM you want, you need to match the p/n with the OS you want to run. Ex can't run a 2006 OS in a 2009 ECM and vice-versa, it will brick itself.
GMPX
May 17th, 2013, 10:47 AM
I don't tend to hear of them going bad, the common problem we always hear about is other tuning programs flashing in wrong year model OS's, that'll cause all sorts of weird problems, sometimes a no start.
ls1mike
May 18th, 2013, 04:57 AM
This vehicle has been to at least 3 tuning shops over time and definitely efilive and hptuners and who knows what else. Could be it, maybe? Lets hope its that simple.
GMPX
May 19th, 2013, 11:20 AM
Yes it could be that, do you have access to be able to use TIS2WEB to get the factory stock tune put back in it?
ls1mike
May 19th, 2013, 03:32 PM
No, found a matching vehicle computer will swap this week and see what happens. Fingers crossed.
GMPX
May 19th, 2013, 05:35 PM
Still not going to work, it'll need to be set up with TIS2web FIRST.
ls1mike
May 27th, 2013, 09:02 AM
Can't reprogram vats or other things? I will be working on this again tomorrow.
ScarabEpic22
May 27th, 2013, 05:59 PM
Can't reprogram vats or other things? I will be working on this again tomorrow.

Yes, but it wont matter if you dont have the correct base system/platform programmed into the ECM already (via TechII/Tis2Web).
Highlander
May 27th, 2013, 09:30 PM
The only bad E38 ECU i have encountered displayed IAT and ECT at -40. Wiring was OK...... Replaced ECU.. problem solved.. I still have it here just for not throwing it away.
ls1mike
May 28th, 2013, 03:42 AM
No crank with the supposedly set up computer, tried key forward for 10 minutes 3x twice, still no crank. Whats the proper procedure for this computer? Should I apply a vats delete patch? I don't want to screw with it too much after all the trouble we have had.
Highlander
May 28th, 2013, 05:19 AM
You are not going to damage it with efilive. No matter what you do. That being said... Use the OEM tuning program to flash a factory system. You must verify part numbers as part numbers changed across the years.
ls1mike
June 7th, 2013, 11:03 AM
Replaced the computer and solved the intermittent starts... who knows.

Wasn't easy had to bring it to a place with a dealer tool to get it to turn over.
Hi-flow
June 21st, 2013, 02:57 PM
Did this vehicle play up again or is it all sorted now? I just made a thread about hot starts which looks to have almost identical symptoms. Hopefully this may be the answer I was looking for! I have wasted hours chasing this issue. Did you try a full Operating System flash instead of a Cal flash, before changing the ECM?