There will only be potential issue with the key's rolling codes/immobilizer if the key is in the ignition (engine off, key in any position) and you jump the car (with yours having dead battery). As long as the key is out and in your pocket when you give the car a voltage spike, you'll be pretty much guaranteed of not having any issues.

For future FYI: if your car is the car to be jumped, jumping via the terminal in the engine bay is OK...that's what it's there for. The battery cable system is more than adequate for any sort of 12V testing, jumping, charging, etc. Anything otherwise is paranoia.



How do you define the transmission not working "quite right when cold"?

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Allen Kroliczek
Oak Grove Autosport | Oak Grove Autosport
01 G500, 82 300TD, quite a few more.....