Common reasons car keys stop working

A car key that stops working is rarely mysterious. Usually it is one of five things, and two of them you can check yourself in under a minute. Consequently it is worth ruling those out before booking anything.

The battery, first and most often

A flat fob battery accounts for a large share of these calls. Consequently the doors stop responding and the car may refuse to start. However, almost every fob hides a mechanical blade, and most vehicles have a keyhole under a cap on the driver's door handle. Furthermore, holding the fob against the start button usually works because a backup coil sits behind it.

Worn blade, worn ignition

A key that needs a specific angle is describing wear. Because the blade thins and the wafers wear together, they eventually stop aligning. Therefore replacing only the key gives you a fresh key in a worn cylinder, which wears quickly too. Consequently the honest fix often addresses both.

Transponder and programming faults

If the key turns but the engine will not start, the immobiliser is not recognising the chip. Sometimes that follows a battery disconnection or an electrical fault. Meanwhile a key cut at a hardware counter will never start the car, because only the blade was copied. Therefore any car key from 2001 onward needs programming, not just cutting.

Water, drops and general abuse

Fobs live in pockets and go through washing machines. Consequently water damage is common. Additionally a cracked shell lets moisture in gradually rather than all at once. However, the electronics often survive, so a shell swap can save the fob entirely. Therefore bring us a damaged fob before assuming it is finished.

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