Problems after battery change -2005 MMT

[Brighton]

Originally Posted by tmontague

Coincidentally I have noticed that letting my yaris idle for 20 or so minutes fixes the idle hunt issue from disconnecting the battery- it's possible that manufacturers or dealers let the cars idle for a specific amount of time without touching the throttle

For what it's worth Subaru's do the same thing, there is a little procedure you have after a battery swap. You do a few specific things with the key in the ignition to start the learn procedure but once you start the process, the car will change idle every 10 seconds over the span of 5 minutes until it learns what it wants to do, then it's fine. If you ignore this step and just drive it, it'll idle horribly and randomly for a good few days of daily driving. I would think there is something similar for other manufactures as well.