ECU Resetting itself

Shellshock · Jul 18, 2018

bshammer0[OP] initial post: ↑

I doubt many have had this issue or, if they have, are unaware of it but I won't know if I don't ask!

I've had an intermittent issue w/ my truck for several months. I call it an "issue" because it's abnormal though it hasn't adversely impacted performance and the truck has always started but it's odd.

What happens: The ECU / DTCs clear unexpectedly from time to time. Similar to the behavior you would get when disconnecting a battery or clearing DTCs. The best way you know this is happening is that when firing up the truck, there is a split second delay where it sounds like the ECU is getting an initial airflow reading before it sparks the ignition for the first time.

I then plug in my Carista and OBD Fusion app and can see the clear signature of an ECU reset (miles since DTCs cleared are 0, warm-ups since cleared are at 0-1, etc.,) and the truck restarts its learning behaviors for ignition timing, fueling, etc.,

Things I've tried: Replaced my stock battery with a Northstar and it's strong as it gets so it's not that. Make sure there are no power draws when I have the truck shut off or when starting up. At one point I thought that perhaps b/c I leave the Carista plugged in that could be the cause but it isn't since I had this happen yesterday.

One other note is that it generally seems to happen when I have been driving the truck (warm engine) then let it sit for a short period (less than 90 mins) and fire it back up. Doesn't seem to happen on a cold start.

While not a "big" issue now it is concerning if it could be an electrical gremlin or ECU issue that could bite me down the line. I do know the ECU is intended to hold it's memory and not reset (dealerships go to great length to ensure power isn't interrupted to the ECU when doing service) so the behavior is not normal.

Anyone had this happen?
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I’ll have to check mine and see if I’ve had any resets. I’ve had some odd things happen on startup a few times but the truck has always started so I never worried about it. I’m also running an ARB fridge off the OEM battery which I figured might be part of the problem but I haven’t gotten around to replacing the battery yet.

dingel5 · Jul 18, 2018

MOC221_ said: ↑

NO. Just no.

Ask @dingel5 what he thinks of that idea
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Stay the hell away from stock! Trust me it’s not a pretty thing. Especially after running thousands of miles with the OVTune.

MOC221_ · Jul 18, 2018

Ok so it's definitely not happening on my truck. I reset Trip ODO "A" when I flashed 1.04A M/T 91 Octane file, reads the same as below (2797km):

TO BE CLEAR - IT'S NOT AN OVTUNE THING PEOPLE!

bshammer0 · Jul 19, 2018

Does anyone happen to have a link to a write-up or video or image that shows how I can access my ECU? I know generally where it is but not entirely sure how to access. Should probably at least get a visual to ensure water or something hasn't gotten in there...

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ECU Resetting itself

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Shellshock King Shit of Turd Island

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ECU Resetting itself

#21 Shellshock King Shit of Turd Island

#22 dingel5 Mocphus

#23 MOC221_ 3 pedal metal

#24 bshammer0 [OP] Well-Known Member

Products Discussed in Entire Site Forum: 3rd Gen. Tacomas (2016-2023)

#21
Shellshock King Shit of Turd Island

#22
dingel5 Mocphus

#23
MOC221_ 3 pedal metal

#24
bshammer0 [OP] Well-Known Member

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