Remote or valet key both use passive RFID for EWS. That's why un paird or dead bat key will still start the car.

If a trace breaks on the RFID circuit you can have an intermittent situation where the ckt makes contact when twisting the key just right.

I just helped replace a key cylinder/switch on a Ford and it came with two new chipped keys and one not chipped.

Good thing the non chipped came with.

To add the new keys to the DME there's a fairly simple method but it required two coded keys which no longer turn the lock!

Solution: use the new non chip key and one at a time old chipped keys held against. Too bad bmw doesn't do similar.

The bummer for Ford victims is you will figure out you need two working keys when you lose one and buy a replacement!


–awr–

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)