This question usually reaches us from a driver in Glasgow holding somebody else’s quote. They have a figure for two tyres, and the question behind it is whether we replace TPMS sensors when fitting tyres, or whether that is the thing that makes the figure grow once the wheel is off.
So here is the answer straight away. A new valve or TPMS service kit goes on as standard on every fit, and it is inside the quoted price. A full sensor replacement is a different job, priced separately, and confirmed with you on the call, never sprung at the kerb.
The two get lumped together constantly, and the lumping is where the surprise bills live. This page pulls them apart properly, explains what happens to your TPMS during an ordinary tyre change, and covers the one genuinely awkward scenario in this trade honestly. We are out fitting 24 hours a day, 7 days a week, and nothing about TPMS should be a surprise once the wheel is off.
The Short Answer: Do We Replace TPMS Sensors When Fitting Tyres?
We replace the TPMS service kit as standard on every fit. That is the rubber grommet or snap-in stem, washer, nut, valve core and cap, and it is included in the fitted price. The sensor itself is only replaced if it has failed, and that is a separate job agreed with you first.
That single distinction answers most of the search. The consumable sealing parts are renewed every time, inside the figure you were quoted. The electronic sensor is touched only when the evidence says it needs to be, at a price you hear before anything happens.
The Service Kit and the Sensor Are Two Different Things
Both live at the valve position on the wheel, and they could not be more different as purchases. Here is the split.
| TPMS service kit | TPMS sensor | |
| What it is | Grommet or stem, washer, nut, valve core, cap | Battery-powered pressure sensor inside the wheel |
| When it is replaced | Every fit, whenever the tyre comes off the rim | Only when failed or damaged |
| Included in the fitted price? | Yes, as standard | No, a named genuine extra |
| Cost context | £5.99 to £25 per wheel, inside the fitted price | Priced separately, agreed on the call |
What a TPMS Service Kit Is
The kit is the set of small parts around the sensor: the rubber grommet or snap-in stem, the washer, the nut, the valve core and the cap.
The rule is simple. Every time a tyre is removed from a rim with a direct sensor, those parts should be replaced. They are the sealing and clamping components, they get compressed and disturbed by the job itself, and reusing a squashed grommet is how slow leaks start. They are consumables, like the oil filter at a service.
As a standalone part, a kit is worth £5.99 to £25 per wheel. On our jobs it sits inside the fitted price rather than being added to it, listed in the published inclusions alongside the tyre, fitting, balancing and taking the old casing away.
What a TPMS Sensor Is
The sensor is the battery-powered unit inside the wheel that measures pressure and transmits it to the car. It is not a wearing part in the normal sense. It is an electronic component with a sealed, finite battery, and it lives inside the tyre where nobody sees it for years at a time.
Sensor replacement is one of our four published genuine extras, alongside run-flat tyres, rims over 18 inches and locking wheel nut removal. Named in the open, so nobody meets it as a surprise.
Why the Two Get Confused
Both sit at the valve, both get handled during the same job, and plenty of quotes blur them together, sometimes carelessly and sometimes conveniently.
The practical takeaway costs you one question. Ask any fitter whether the service kit is included and whether a sensor would be an extra, and get both answers before the wheel comes off.
Does Your Car Even Have TPMS, and Which Type?
Most cars on UK roads now do, but the type decides what any of this means for you.
Direct TPMS
A battery sensor sits inside each wheel and reports the actual pressure of that corner to the car. Battery life is typically 5 to 10 years. This is the type where a service kit matters at every fit, and the type where a sensor can eventually fail.
Indirect TPMS
No hardware in the wheel at all. The system uses the ABS wheel speed sensors to spot a soft tyre from the way its rolling radius changes. Nothing to replace, nothing to program, and after a pressure change or a tyre change it simply needs a reset.
Which Cars Have It
TPMS became mandatory on new passenger car type approvals from 2012, and it is fitted to most cars first used on or after 1 January 2012. Some older cars carry it as an option. If your dashboard has ever shown a tyre pressure symbol, you have it, and our guide to what to do when the TPMS warning light comes on covers the symbol itself.
TPMS and the MOT
The legal side is short and worth knowing precisely.
TPMS has been checked at MOT since 1 January 2015, on M1 vehicles first used on or after 1 January 2012. A malfunctioning system is a major defect, which means an automatic fail. A TPMS malfunction has been classified as a major defect since the rules tightened, which is an automatic fail.
One nuance matters. A TPMS fault is judged at MOT on whether the lamp indicates a system malfunction, not simply a soft tyre, as the MOT inspection manual sets out. Testers should only fail the system where the lamp clearly shows a malfunction rather than low pressure. So a light caused by a genuinely soft tyre is a tyre problem, while a light the system throws about itself is the MOT problem. Our guide to failing the MOT on tyres covers the rest of the test.
How Long TPMS Sensors Last and Why They Fail in Sets
Sensor batteries are generally good for 5 to 10 years, though heat cycles, mileage and road salt all play a part. The battery is sealed inside the unit and cannot be changed, so a flat battery means a new sensor, not a new battery.
The set behaviour catches people out. Four sensors fitted on the same day live identical lives: the same heat cycles, the same mileage, the same winters. When one reaches the end, the other three are usually within months of the same cliff. We see the pattern regularly on cars around the ten year mark, one sensor gone at the stem and the other three corroded at exactly the same point.
Glasgow deserves its own sentence here. Winter road salt and standing water accelerate corrosion at the valve stem, and a sensor that has spent ten Scottish winters in a wheel is a different proposition to one that has spent two.
Should You Replace All Four at Once?
The honest answer rather than the sales answer. Whether it is worth doing all four together depends on their age and condition, and we will tell you what we can see rather than what is easiest to sell.
If one has died of old age at eight or nine years, the other three are on borrowed time, and doing them together saves paying for the tyres to come off again one by one. If one failed early through physical damage, replacing that one alone is the sensible call. As context, four sensors fitted all in runs £220 to £400, with the detail on our TPMS cost page.
What Happens When a Sensor Snaps During a Routine Tyre Change
Now the part of this subject nobody publishes, so we will.
The mechanism first. Most sensor stems are aluminium, clamped by a nut, sitting in a wet, salted wheel for years. Corrosion builds where the metals meet, and after enough Glasgow winters the stem can shear the moment the nut is loosened or the bead is broken. It can happen with correct technique and correct torque, on a perfectly ordinary job. It is not carelessness. It is chemistry that finished years before the van arrived.
Here is exactly how that moment is handled on our jobs. The fitter stops. You are shown the broken part at the vehicle, in your hand if you want it. Then two options are explained, with the price of each before anything else happens: fit a new sensor now, or fit a standard valve and accept that the warning light will stay on until a sensor goes in, which carries the MOT consequence described above.
Nothing is decided on your behalf, and nothing lands on the bill without being agreed first. Corroded stems can shear on an ordinary tyre change, and if that happens we stop, show you the part and give you the price before any further work.
The reason this conversation works is the quote mechanic underneath it. Your original figure was agreed on the call before the van moved, so any change is a visible, explained, separate decision, never a number that quietly grew. We do not guess; we diagnose the problem and provide the safest and most cost-effective solution.
Cloning an ID Versus Writing a New One
When a sensor is replaced, the new unit has to end up speaking to your car. There are two routes.
Cloning the Old Sensor’s ID
The failed sensor’s ID is copied onto the new unit, so as far as the car is concerned nothing changed. No relearn is needed and the dashboard never notices. This route needs the old sensor’s ID to still be readable, which the diagnostic scan establishes.
Writing a Fresh ID and Relearning
A new ID is written to the sensor and then taught to the vehicle, either by a static relearn with a tool at the vehicle, or by a drive cycle where the car picks up the new sensor over a short spell of normal driving.
Programmable Aftermarket Versus OEM
Our published position: quality programmable aftermarket sensors are stocked as standard, and OEM is sourced on request for anyone who prefers the factory part. A good programmable universal sensor performs identically to the factory part. For context, parts alone run £50 to £90 aftermarket and £110 to £180 OEM, with the full breakdown on the cost page.
The Ten Steps of a Sensor Job
- Diagnostic scan
- Bead break
- Tyre removal
- Sensor replacement with a new service kit
- Inflation
- Rebalancing
- Programming or pairing
- Wheel refitting
- Torquing to manufacturer specification
- Warning light confirmation
Why the Light Can Stay On for a Drive Cycle After a Fit
A light that stays on straight after a fit is the single most common callback in this category, and it is usually not a fault.
Where a new ID has been written rather than cloned, the system may need a short period of normal driving before the light clears, because the car registers the sensors on the move. Separately, the system wants correct, settled pressures, and a tyre inflated warm can read oddly until temperatures stabilise. Customers sometimes phone back before the first proper drive has happened, and the light clears on the school run.
What is not benign: a light that stays on well beyond a drive cycle. That means the system needs looking at rather than ignoring, particularly with an MOT due, and both our TPMS warning light guide and what to do when the pressure light stays on after inflation cover the diagnosis.
What TPMS Work Costs, in Short
The summary, with the detail kept on the dedicated pages. The service kit is inside the fitted price on every fit, and standalone it is £5.99 to £25 per wheel. A sensor replaced all in, meaning the sensor, fitting, programming and rebalancing, runs £60 to £150 for a single wheel and £220 to £400 for four. Parts alone are £50 to £90 aftermarket and £110 to £180 OEM.
Our TPMS sensor replacement cost guide and the TPMS sensor replacement Glasgow service page carry the full breakdowns. Whichever applies to you, TPMS work is included in the one total you get on the call, and payment is card at the vehicle, contactless included, after the work.
Frequently Asked Questions
Do you replace TPMS sensors when fitting tyres?
Not automatically. A new TPMS service kit goes on as standard with every fit, inside the quoted price. The sensor itself is only replaced when the diagnostic scan or the wheel shows it has failed, and that is agreed with you, with the price, first.
Does tyre fitting include TPMS?
The service kit, yes. Every fitted price includes a new valve or TPMS service kit alongside fitting, balancing and taking the old casing away. Sensor replacement is a named extra, established on the call rather than discovered at the roadside.
What is a TPMS service kit?
The consumable parts around the sensor: the rubber grommet or snap-in stem, washer, nut, valve core and cap. They seal and clamp the valve, they are disturbed every time a tyre comes off the rim, and replacing them each fit is what prevents slow leaks.
Why is my TPMS light on after new tyres?
Usually a drive cycle. Where a new sensor ID has been written, the system may need a short period of normal driving before the light clears, and warm-inflated tyres can read oddly until they settle. A light that persists well beyond that needs checking.
How long do TPMS sensors last?
Sensor batteries are generally good for 5 to 10 years, though heat cycles, mileage and road salt all play a part. The battery is sealed, so a flat one means a new sensor. Sensors fitted together tend to fail within months of each other.
Will a TPMS fault fail an MOT?
Yes. TPMS has been checked since 1 January 2015 on cars first used on or after 1 January 2012, and a malfunction is a major defect and an automatic fail. The test judges whether the lamp shows a system malfunction, not simply a soft tyre.
What happens if a TPMS sensor breaks during a tyre change?
Corroded stems can shear on an ordinary tyre change, especially after years of Glasgow road salt. If that happens we stop, show you the broken part at the vehicle and give you the price of the options before any further work. Nothing is added without agreement.
Are aftermarket TPMS sensors as good as original ones?
A good programmable universal sensor performs identically to the factory part, which is why quality programmable aftermarket sensors are our standard stock. OEM is sourced on request for anyone who prefers it, with parts running £110 to £180 against £50 to £90 aftermarket.
Book a Fit With the TPMS Answered Up Front
Send three things to 07955 533000 on phone or WhatsApp: your registration, your postcode, and whether the dashboard light is currently on. That lets the office confirm on the call whether your job is a standard fit with a new service kit or whether a sensor is likely to be involved, so the figure you get is the full one.
We are 24/7 Mobile Tyre Services, family run for over 20 years with fully certified technicians, based at 100 Jessie St, Polmadie, Glasgow G42 0PG, working 24 hours a day, 7 days a week in all weather, with an average arrival of 30 to 45 minutes across Glasgow and the Central Belt. One total on the call, before the van moves.
