Engine died and stranded my MSM! Dead battery or ECU related?
 

So I have had my MS2 Enhanced ECU for about 5-6 months and have not had many issues with it since the install. The base map that Rev loaded pretty much had the car running and idling well and all that I have done is tweak the fuel and AFR tables, and also added 1* of timing in the spark table upper cells So I went out for a drive Saturday and everything was fine, I simply went out for some logs to try and find the culprit for a super rich condition on hot restarts.

Yesterday, I went for a tuning drive, just wanted to adjust my AFR targets and go on a 45 min VEAL tuning run. All was fine, then I stopped and saved my tune and un-plugged the laptop to just cruise home I got about 8 miles away from home and my radio dies. Just dead no power. Another mile and all the lights and indicators on my dash start flickering, flashing…gauge needles start franticly going up and down and then everything read 0.

My gauge cluster dies and then the car starts stumbling and then dead! Nothing…rolled into a ditch in neutral and the car was dead. After turning the key on/off I could get power, plugged in the laptop, turn the key, no FP prime but in tuner studio everything came up and there were no red flags…but then when I turned the key nothing, not even clicking….I got my friend to come with some tools and a chain, and we pulled it to the closest gas station…. I re-set the battery and then I got power, and gauges working, but this time just clicking…everything pointed to a dead battery, but it made no since because I have never seen a battery just take a crap like that in the middle of running.
That’s why I want to know what you guys think; I’m super worried that it is ECU related. After getting it home I disconnected the MS ECU and connected the stock ECU, we put jumper cables on the battery and the car started! So then I re-connected the MS ECU and we put the jumpers back on… first 2 tries it fails to start, then the third try it stumbled and started just barely but we were in a hurry so I never tried to jump it back off again. It’s been setting in my driveway since. All things point to just a plain-old dead battery…but I’m dumbfounded because of how sudden and odd the death of my car was, I had no indication of low voltage, but I was not watching my volt gauge so I don’t know.
All I have to show is the logs that I took the day before, and also the car is a 2005 MSM with a new Rev Built MS2. Had a new alternator installed last year, and IIRC when that happened the car was running weak and the battery light kept coming on and it would die. I had the battery checked and it was supposedly fine.


UPDATE:
Just got back with a new battery, it’s the same as the last one, 500CA and 370CCA. Put it in and the car started right up and idles fine. Have yet to drive it again because im scared I may get stranded. I have reason to belive that it could have been ECU related.I wanted to see if you guys knew of any setting in tuner studio that could have killed that battery or caused it to die like that.

when they tested the old one it had 135 CA and its almost 6yrs old. Im just wondering if there are any battery voltage settings that may have had a play in this and if my car is safe to drive again. it just really freaked me out when my gauges went hay wire and my car started making all these weird clicky noises. I thought I may have fried the ECU or something or done some kind of damage. Or maybe the battery was just so damn dead that it couldn't take it anymore

apologies for my frantic post and bad grammar.

Main relay?

Check your wiring grounds. Sometimes they can get oxidized or come loose and cause strange intermittent electrical behavior similar to what you're describing.

Did this ever get resolved? I'm interested what caused the dying of battery after ECU install

Sounds like an alternator issue to me.

+1 for the alternator

Alternator is my guess as well.
If everything slowly died, and slowly shut off, its definitely that.
Had the same problem with mine and replaced it with an AutoAdvancedPOS one and did the same thing after replacing.
I would suggest OEM if you can afford it, or if you go to a local parts store have them test the alternator before you pay for it.