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Carlz0r
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Last seen: 3 years 3 months ago
Joined: 02/10/2015 - 11:07
ECU sometimes shuts off while cranking

I have a 30-6310 ems and have noticed that it will sometimes die while cranking. By die, I mean I lose connection, am unable to reconnect, and the ecu does not output anything (no spark etc.) I then have to power cycle the ignition to get the ecu to run again. I believe it is happening when my battery voltage is lower than it should be, wondering if this is actually the cause or just coincidence? Any troubleshooting tips would be much appreciated!

AEM_NS
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Last seen: 1 day 20 hours ago
Joined: 06/06/2014 - 09:31
Yep, you've got the cause and

Yep, you've got the cause and effect right.  Battery volts drops below min voltage requirement for EMS to be on and running and the EMS shuts off.  Interesting that this is happening on a Mitsu as this most often seems to happen on Nissan cars that have a rear mounted "racing" battery with poor wiring.  Voltage drops don't discriminate though and you might be having the exact same problem.  

Carlz0r
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Last seen: 3 years 3 months ago
Joined: 02/10/2015 - 11:07
AEM_NS wrote:

AEM_NS wrote:

Yep, you've got the cause and effect right.  Battery volts drops below min voltage requirement for EMS to be on and running and the EMS shuts off.  Interesting that this is happening on a Mitsu as this most often seems to happen on Nissan cars that have a rear mounted "racing" battery with poor wiring.  Voltage drops don't discriminate though and you might be having the exact same problem.  

I have an Odyssey PC625 battery up front but it is essentially at end of life and a small battery to begin with so it sounds like this is likely the problem. Thanks!

Carlz0r
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Last seen: 3 years 3 months ago
Joined: 02/10/2015 - 11:07
Just wanted to post an update

Just wanted to post an update as it might help others in the future. Got my new battery installed, problem is gone. It was indeed battery voltage dropping too low while cranking.

JKrzeminski
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Last seen: 7 months 4 weeks ago
Joined: 08/13/2019 - 10:32
This too happens to my

This too happens to my Infinity 508 EMS. I have a completely custom battery wiring setup. Its a boxster with a motor swap = very small Odyssey PC680 Battery in front with engine in the back. The explanations above make sense. Looks like I may have to upgrade.