A key fob range gets shorter in most cases because the coin cell in the fob is weak, since range drops before the buttons stop, and a new coin cell restores the full distance.
Key fob range getting shorter is the fault where the remote buttons lock and unlock the car only from closer than before. A remote fob reaches 5 to 30 metres on most cars in open air and sends on 433 MHz in the UK. Range is the first thing a fob loses, so a shorter range is an early warning and not yet a failure. Two tests find the cause. The spare fob shows whether the fob or the car is at fault, and a second location shows whether interference is at work. Six causes explain a shorter range, and five fixes in order restore it. A fob battery fitted and tested costs from £25 in Liverpool, and a button or case repair costs from £45.
A very short range, ways to extend the range, battery life, cold weather, a fob that works only at the door, the head trick, a new battery, a short range after a new battery, one car park, a signal blocking pouch, both fobs, a phone, reprogramming, a battery change and keyless entry raise fifteen further questions.
The list below gives four key takeaways on a key fob range getting shorter.
- A weak coin cell is the most common cause, and the range shrinks weeks before the buttons stop.
- A spare fob that reaches further puts the fault in the everyday fob, and two fobs that fall short together point to the car.
- A range that is short in one place only is interference, with no fault in the fob or the car.
- An auto locksmith repairs a cracked aerial track or a worn fob at the car, with no new fob in most cases.
What fixes a key fob range getting shorter?
Five fixes restore a key fob range getting shorter, and a new coin cell clears the most common cause. The list below gives the five fixes in order.
- Fit a new coin cell of the type printed on the old cell, from a known brand, with the plus side facing the same way.
- Try the spare fob from the same spot, which shows whether the fob or the car is at fault.
- Test the fob in a second location, since a range that returns there points to interference.
- Unplug a dashcam, charger or tracker that was added to the car before the range dropped.
- Charge the 12 volt car battery where both fobs fall short.
A fob held at chest height adds a few metres while the cause is traced. A key fob range that stays short after all five fixes points to a worn fob or to the receiver in the car.
What is a normal key fob range?
A normal key fob range is 5 to 30 metres on most cars in open air, and the figure changes with the car, the fob and the surroundings. The table below gives three usual distances.
| Key type or state | Usual range |
|---|---|
| Remote fob with a fresh coin cell | 5 to 30 metres in open air |
| Remote fob with a weak coin cell | 1 to 2 metres |
| Keyless entry at the door handle | 1 to 2 metres by design |
Two cars of the same year differ, since the number of aerials in the car and their position set the reach. Walls, parked cars and rain shorten the distance on any car. The distance at which the car answered last year is therefore the measure for a key fob range today, and a steady fall from that distance is the sign of a fault.
Why does a key fob range get shorter?
A key fob range gets shorter because the fob sends a weaker signal, something drowns the signal or the car hears it less well. The list below gives six causes in order of frequency.
- A weak coin cell lowers the sending power, and cold weather lowers it further.
- Interference from a mast, a steel and concrete car park or nearby electronics drowns the signal in one place.
- A dashcam, charger or tracker fitted inside the car gives off radio noise beside the receiver.
- A cracked aerial track, a cracked solder joint or corrosion inside the fob weakens the signal.
- A weak 12 volt car battery lowers the sensitivity of the receiver.
- A damaged receiver aerial, often set in a window or the rear screen, hears the fob late.
The first cause accounts for most cases. A key fob range that fell on both fobs in the same week points to the last two causes.
Which two tests find the cause?
Two tests find the cause of a shorter key fob range, the spare fob test and the second location test. The table below reads four results.
| Result | What it means | Next step |
|---|---|---|
| The spare fob reaches further | The everyday fob is at fault | A new coin cell, then a fob repair |
| Both fobs fall short in every place | The car is at fault | The 12 volt battery, then the receiver |
| The range is short in one place only | Interference at that place | No repair |
| The range fell after a new accessory | Radio noise inside the car | Unplug the accessory |
A spare that sat in a drawer for years has an old cell of its own. A fresh cell goes into the spare first, so the comparison of key fob range is fair.
Does a shorter range mean a failing fob?
A shorter range means a failing fob only where the range stays short on a new coin cell.
With a weak cell the fob itself is sound. The range falls first, then the buttons take two or three presses, then the remote stops. On a new cell, a range that stays short points to a hairline crack in the aerial track or to a cracked solder joint, and the crack grows with every drop. A repair at this stage keeps the chip that the car already knows. A key fob left until the remote stops costs more, since a new fob is cut and programmed.
Who repairs a short range key fob?
An auto locksmith repairs a short range key fob where the fob is at fault, and an auto electrician repairs a receiver, an aerial or a wiring fault in the car.
The work happens at the car. The coin cell and the signal of the fob are tested, the spare is compared and the circuit board is checked for cracks and corrosion. ADC Locksmith Liverpool carries out the repair of a key fob in Liverpool from £25 with no call out fee and no VAT, 24 hours a day. Craig Evans holds SERMI approval, the accreditation for access to the security data of the car maker. A fob beyond repair is replaced and programmed in the same visit. The lock, unlock and boot buttons are tested from a distance before the job closes.
What does a key fob range repair cost?
A key fob range repair costs from £25 for a battery fitted and tested, and from £45 for a button or case repair in Liverpool. The table below compares four outcomes of a shorter key fob range by price.
| Outcome | Price | Who does it |
|---|---|---|
| New coin cell fitted at home | £2 to £5 | The driver |
| Fob battery fitted and tested at the car | From £25 | ADC Locksmith Liverpool |
| Button or case repair | From £45 | ADC Locksmith Liverpool |
| New remote key cut and programmed | From £120 | ADC Locksmith Liverpool |
Most cases end at the first row. A fob repair at the car takes 15 to 30 minutes.
What else do drivers ask about fob range?
Drivers ask about fob range in fifteen further questions on a key fob range getting shorter. A very short range, ways to extend the range, battery life, cold weather, a fob that works only at the door, the head trick, a new battery, a short range after a new battery, one car park, a signal blocking pouch, both fobs, a phone, reprogramming, a battery change and keyless entry are the fifteen topics, and the questions below answer each one.
Frequently asked questions
Why is the key fob range so short?
The key fob range is so short in most cases because the coin cell is weak.
Interference, a worn fob and a weak car battery are the next three causes.
How do drivers extend the range of a key fob?
Drivers extend the range of a key fob with a new coin cell, a higher hold and a clear line to the car.
A fob held at chest height clears the cars parked in between.
How long does a key fob battery last?
A key fob battery lasts about 3 to 4 years in normal use.
Cold weather and a keyless system shorten that life.
Does cold weather shorten key fob range?
Yes, cold weather shortens key fob range, since a cold coin cell delivers less power.
The range returns as the fob warms, and a cell near the end of its life shows the drop first.
Why does the key fob work only at the door?
The key fob works only at the door where the coin cell is close to flat.
A new cell restores the range, and a range that stays short points to the circuit board.
Does holding a key fob to the head add range?
Yes, holding a key fob to the head adds range by a few metres.
The water in the body carries the signal and acts as a larger aerial.
Does a new battery restore key fob range?
Yes, a new battery restores key fob range in most cases.
A range that stays short on a new cell points to a cracked aerial track or to the car.
Why is the range short after a new battery?
The range is short after a new battery where the cell is a weak brand, the wrong type or seated on a bent contact.
The guide to a key fob not working covers the checks after a battery change.
Why is key fob range short in one car park?
Key fob range is short in one car park because of interference from the structure or from nearby transmitters.
The fob and the car have no fault where the range returns elsewhere.
Does a signal blocking pouch shorten key fob range?
Yes, a signal blocking pouch shortens key fob range to zero while the fob sits inside.
The article on which material blocks a car key signal explains the pouch.
Why did both key fobs lose range together?
Both key fobs lose range together where the car is at fault or both cells are the same age.
A weak 12 volt battery and a damaged receiver aerial are the faults in the car.
Does a phone shorten key fob range?
Yes, a phone shortens key fob range where the two sit pressed together.
A second fob in the same pocket has the same effect.
Does reprogramming improve key fob range?
No, reprogramming does not improve key fob range, since coding sets which fob the car accepts and not the reach of the signal.
A fob out of sync fails at every distance.
Where is a car key battery changed?
A car key battery is changed at home, at a key cutting shop or at the car by an auto locksmith.
The guide on where to get a car key battery replaced compares the options.
Is a keyless entry range shorter than a remote range?
Yes, a keyless entry range is shorter than a remote range, at 1 to 2 metres from the door handle by design.
The remote buttons on the same fob still reach 5 to 30 metres.
Based in Liverpool and still stuck?
ADC Locksmith Liverpool repairs, programs and replaces car keys at the roadside across Liverpool and Merseyside, usually on the same day. Craig Evans holds SERMI approval and a 5.0 rating from 341 Google reviews. A call to 07731 544220 brings a fixed price before Craig travels.
Call 07731 544220