Tech Tip to clean Throttle Body after battery disconnected. (Note: This is not new, just was hard to find.)
The ECU has "learned" to use the Throttle Body in its dirty condition. When power is disconnected, it wipes the ECU memory and the learning has to start again. The default settings assume a clean (and new) Throttle Body, but it is not and the "learning" can take some time to complete, during which the car will run rough. On a "normal" ICE car, a 15-25 minute drive at various speeds usually completes the learning cycle, but with a Prius, the ICE might not run long enough at certain speeds. Note that the tip is for most all Toyotas, not just hybrids.
You're welcome. Also of note: this is not recommending that the TB is serviced every time the battery is disconnected, just a reminder to the techs that if the car runs roughly after a disconnection, it is a good idea to check (and likely need to clean) the TB. hope this helps!
90% of the time, most Toyota’s do the throttle body reset on the first startup after reconnecting battery. They start and immediately die. Restarting finishes reset procedure unless TB is extremely dirty. I install batteries daily as part of my job description. Most cars with electronic throttle bodies say not to use a memory saver. The memory saver prevents the reset from occurring.
