Ford 'Key Not Detected' — What It Means and How To Fix It

"Key Not Detected" appears on Ford models with keyless start (Ford calls it Intelligent Access) — commonly the Fiesta, Focus, Kuga, Puma, Mondeo and S-Max. It means the car tried to find the key's signal and could not. Sometimes the car still starts on a second attempt; sometimes it will not start at all. The cause is usually simple. Here are the checks to work through, in order.

Quick checks first

• Try your spare key. If the spare works every time, the problem is the first key, not the car.
• Move phones, chargers, dash cams and other keyless fobs away from the key and try again — strong interference can block the signal.
• Hold the key against the backup position shown in your owner's manual (on many Fords it is marked on the steering column or in the centre console) and press start. If the car starts this way, the key's transponder is fine and the keyless signal is the weak point.

1. Flat or weak key battery

By far the most common cause. The keyless signal weakens before the buttons stop working, so a key can still lock and unlock and yet not be detected inside the car. Most Ford keyless fobs take a CR2032 coin cell — check yours before buying. Fit a quality battery and try again.

2. Weak car battery

A low 12-volt battery can cause keyless faults and a string of unrelated warnings. If the car has been standing, cranks slowly or recently needed a jump-start, have the battery tested before you replace the key.

3. Damaged key

Keys that have been dropped, soaked or sat on can lose the keyless function even when the buttons still work. If a new battery and the backup position do not help, and the spare key works, the original key is the likely fault. It can be replaced and programmed to the car without going to a dealer.

4. Car-side antenna or receiver fault

If no key is detected — including a spare with a fresh battery — the fault may be in the car: an interior keyless antenna, its wiring or the receiver. That needs a diagnostic check with the car's own fault codes rather than a new key.

5. Key no longer paired

Occasionally a key stops being recognised after module work, a battery replacement on the car, or an aftermarket key that was never coded properly. Re-programming the key to the car usually restores it.

When to call

If the quick checks have not fixed it, or you have only one key and the car will not start, call or WhatsApp with your registration and tell us what the dashboard shows and whether the spare works. That narrows down the cause before anyone sets off.