Car Key Fob Repairs in Exeter

The most reliable self-test is the LED indicator. Most key fobs have a small red LED that flashes when a button is pressed — if you press a button and see no flash at all, or a very dim one, the battery is the prime suspect. If the LED flashes normally but the car does not respond, the fault is more likely a resync issue or circuit problem. Most fob batteries are CR2032 or similar — a quick check against your vehicle handbook confirms the correct size. The RAC recommends changing fob batteries every 3–4 years as routine maintenance. We carry all common fob battery types and test after fitting before leaving.

This happens more often than you might expect and is almost always a resync issue. When the battery is removed, some fob types lose synchronisation with the vehicle — the rolling code sequence between fob and car falls out of step. The resync procedure varies by make and model but usually involves a specific sequence of button presses while in range of the vehicle. We carry out resync for all major makes. If resync does not resolve it, the new battery may be the wrong type or have poor contact with the circuit terminals — something we check as part of every fob diagnosis.

When two fobs fail simultaneously, the fault is almost certainly not in the fobs themselves. Both fobs developing the same fault at the same moment is statistically extremely unlikely. The most probable causes are a vehicle-side fault — the receiver module in the car has failed — or a mass resync event caused by a battery event or electronic reset in the vehicle. We diagnose the exact cause on site. See also our immobiliser diagnostics service if the car also has starting issues alongside the fob problem.

Often yes. Button failure is usually one of two things: the rubber button pad has worn through and the conductive carbon contacts underneath no longer make reliable contact with the circuit board, or the circuit board tracks underneath the buttons have corroded. The first is repairable with a replacement button pad (available for most popular makes). The second depends on the extent of the corrosion. We assess the specific fault and repair where we can — replacing only when repair is not viable.

Possibly, but it is worth noting that if the car starts normally, the transponder chip inside the key is working correctly — that is a completely separate system from the remote locking. The remote locking fault could be in the fob’s RF transmitter, the vehicle’s receiver module, or a resync issue. If locking works from the door lock button but not the fob, the fob or its battery is the most likely cause. If locking is entirely absent, the vehicle receiver may be at fault. We diagnose exactly which component has failed. Read more in our guide: key fob stopped working — what to check.

Reduced range is a classic early sign of fob degradation — usually a weakening battery or a deteriorating RF transmitter circuit. A new battery resolves it in the majority of cases. If a fresh battery does not restore normal range, the transmitter coil or circuit board may have partial damage. We test signal strength on site and identify whether the fault is battery-related or circuit-related before recommending any further work.

Act immediately. Remove the battery as fast as possible — with the battery out, no current can flow and no corrosion can begin. Do not use a hair dryer or oven to dry it — heat warps plastic and can damage circuit components. Do not use rice — it absorbs atmospheric moisture but does nothing for internal circuit moisture. Leave the fob open and battery removed in a dry warm location for at least 24 hours, then call us. Water damage caught within hours is often fully repairable. Left for days, the corrosion progresses to the point where repair is no longer viable.

Yes — if the fob is genuinely beyond repair, we supply and programme a replacement fob assembly for most makes and models. The process is the same as adding a new key — the replacement fob is paired to your vehicle’s central locking receiver. Call with your vehicle registration and we confirm availability and cost before arriving. See our spare car keys service if you also need the blade cut and transponder programmed alongside the new fob.