what does re learn mean?

If a mechanic changes a certain component or disconnects the battery or deletes codes on you engine, it may idle poorly, stall, shift erratically and generally run badly for a while until the engine control module "relearns" it's new settings. Be patient and after a few drive cycles and it will run well again. If it doesn't correct itself, call your mechanic and he may confess to messing something up. But not to worry, it usually goes back to normal pretty fast.

Relearn can be done by disconnecting fuses #10 and #28 under the hood for 30 min. After relearn, if it starts to idle bad, especially when AC or defroster are on, take the fuses back out and clean your throttle body.