09 yaris hatch has gone nuts

[kenora]

09 hatch le 4 dr auto 1.5 l ....I was on the highway yesterday when the car started hesitating.. I could feel it miss every few seconds..then it got bad enuff the cruise would kick off.. then the engine would actually shit off for a second and restart causing a major thump. It was as if the key was being turned off..on..since the dash would go black for a moment then illuminate again...
I had to drive in 3 instead of d due to the transmission constantly shifting to neutral and the rpms flaring to 5000 or more.. I slowed to 80 kph.
I limped to a family memebrts place and shut it down for the night.. this morning there was no response from the key..just a hard click from a solenoid under the hood.. I thought the battery was dead..its newish...
The electric locks would not work I had to use the key to lock it and the doors last nite
I opened the hatch this morning and suddenly it tries to start..the starter was engaged and turning the engine e over...the car wouldn't start but it turned over fora coupe of minutes while I tried to stop it...I put the key in the ignition and turned it to every position but no luck it kept turning over..then I tried to shift to drive and it stopped.
Open the hatch and it does it again..
It's getting towed to Toyota but really WTF?

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[Brighton]

It's really hard to say without being there in person to do some simple diagnostics. But when I've had cars do a random assortment of stuff similar to what you describe, it ended up being the ECU failing. I don't know if this is a common issue with Yaris' but I'd do some simple stuff, check air, fuel, charging system etc to try and narrow it down first. IF it's the ECU, I'd try to find a used factory unit in ebay or from a junkyard. In my experience, the aftermarket/refurb ECUs don't run/work exactly like factory.

[kenora]

My thought went to the ecu as well.. I hope not they are crazy expensive

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[Brighton]

I just did a quick browse around ebay, they all seem to be <$120 so not bad, but definitely find the exact model of your existing one and confirm it's identical to the one you find to replace it. There are tons of minute differences. This is ALL assuming the ECU is even bad, this could be as simple as bad grounds.

[kenora]

its fixed...

turns out the (after market) remote start ground wire had corroded a bit and was intermittent causing the ecu to go nuts..the installer (about 7 years ago)...used the same master ground as the main fuse from the box under the hood but it was loose and rusty...caused all sorts of high resistance/heat/nastiness

the ecu seems fine and the cruise control module removed... the ground was burned as was a solenoid..they were replaced and the ground cleaned up....thanks Birchwood Toyota
just an fyi for others...

[kenora]

Opps not the cruise control
.it was the remote start.. cruise is ok

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