Keys

[clueless]

Hi all, The casing on my keys have worn out and there are holes in the rubber buttons. I bought replacement shells on ebay and transferred the electric circuit, battery and key from my old keys into the new ones. These seem to work perfectly when I use the remote to open the doors but when I put the key in the ignition the engine won't start and the dash reads Engine Immobilized. If I put the old worn out case back on the key it works fine again. Can anyone explain to me why this is?

[bettyswollocks]

You need to transfer the little black piece that is inside the old fob to the new one this is the transponder chip ,

inside fob is

circuit board

battery

black chip

[clueless]

Many thanks