Weird Key troubles. Advice needed.

[andrewwynn]

If the immobilizer circuit isn't working in the key it's likely a bad solder joint. It can be disassembled and reflowed. Usually it's the other ckt that breaks (fob remote)


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[upallnight]

Originally Posted by andrewwynn

If the immobilizer circuit isn't working in the key it's likely a bad solder joint. It can be disassembled and reflowed. Usually it's the other ckt that breaks (fob remote)


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There is no immobilizer circuit board in the key. The only immobilizer is the chip which is not attached to any circuit. See image of the chip.

[Qsilver7]

Originally Posted by upallnight

There is no immobilizer circuit board in the key. The only immobilizer is the chip which is not attached to any circuit. See image of the chip.

The OP states they have a 2005 X5...which means if they have original BMW remotes...then their remotes are the new style (diamond shaped) remote keys.

The new style keys don't have a loose EWS transponder like what you pictured. The BMW keys that have a loose transponder chip (during the e38/e39/e46/e52/e53 generation of BMWs) are only found in the old style remote keys and all of the non-remote keys.

The new style (diamond shaped) remote key's EWS transponder is soldered to the remote's internal IC board...just like the key's internal battery is also soldered to the IC board (see pics below):

{New Style/Diamond shaped remote key's EWS transponder location}