Today I had the battery replaced on my 2009 Mazda 5. On the way home from the auto parts store where they installed it after purchase, my car stalled out when going through a roundabout and is idling rough as well. Do I need to reset the computer? If so how do it?

 

Disconnect battery, clean throttle body, reconnect battery, start engine with no loads, allow to idle for a few minutes then drive normally.

 

Grim..... with that year can't he do hard reset of the drive-by-wire?
Turn ignition to start position, floor the throttle for about 5 seconds, release and the start engine normally?


However should the throttle body be cleaned make sure to use only throttle body cleaner so as not to damage the electronics'.

 

As the throttle body slowly clogs up over time the PCM learns the small changes in the TPS, when the battery is disconnected the PCM looses this learnt data, when the car is restarted the PCM has no idea on throttle condition.

Cleaning the throttle is the only option.