the EIS is not your old fashioned key switch. If its working by jiggling, there are some broken solders inside - and you will lose the car while driving (very dangerous)

You cannot swap the EIS with another car on a W210 as its the gateway for the can-bus network. To make a new EIS work, it needs to be virginised first then written to the car with its original build code and key hashes.

However there is an ebay user refurbishing EIS but is in canada, they ask for your working key and EIS to be sent to them - they repair it and send it back to you.

Removing the EIS doesnt always require the special tool - you can use a silicone rubber pad that is used to open tight jam/marmalade jars on the face of the chrome beauty ring around the key receptacle to unscrew it.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)