Does disconnecting the batery for an oil change, may affect the the gear system, especially the reverse is not working
Yes it can, it can also remove the programming for all your accessories too, the bad thing is that only the dealer can reflash the system to bring everything back. If you must disconnect the battery there is a tool called a preset or code saver, the cheap ones use a 9 volt battery that plugs into the power port or lighter, but thier time is short, the more expensive ones plug directly into the ODB 2 port and use a jump box or another battery as a power source so the down time is a lot longer. HTH
There is no need to disconnect the battery to change the oil.
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