Tyre Pressure Sensors Common Problems and Repairs: How to Diagnose, Fix, and Maintain TPMS
When the TPMS light appears on the dash, your car is telling you one of two things: a tyre is genuinely low, or a sensor has failed. Either way it is worth sorting, because tyre pressure monitoring is tied to your safety, your fuel economy and your MOT. Our Luton workshop diagnoses and repairs tyre pressure sensor faults across all makes, from a flat battery in a sensor to a corroded valve or a control module fault.
TPMS light on and not sure why? Call us and we will read it properly: 01582 733036
Why the light comes on
A steady light usually means low pressure; a flashing one at start up, or a light that will not clear, points to the sensors themselves. These are the common causes.
| Cause | What is happening |
|---|---|
| Under or over inflation | Pressure outside the car's programmed limits |
| Sensor battery low | Sealed batteries last 5 to 10 years, then the signal drops |
| Corroded valve stem | Road salt and moisture break the seal and the signal |
| Wiring or module fault | A broken connection or control unit interrupting the data |
| Sensor drift | An ageing sensor reporting the wrong pressure |
Direct or indirect: which system you have
There are two kinds of TPMS, and they fail in different ways, so it helps to know which your car uses.
| Type | How it works | Trade off |
|---|---|---|
| Direct | A sensor inside each tyre measures pressure and sends it by radio | Accurate and live, but the batteries eventually run down |
| Indirect | Works out pressure from wheel speed via the ABS sensors | No batteries to replace, but slower to spot a gentle leak |
Repair, replace and what it costs
Because the batteries in a direct sensor are sealed into the unit, we replace the whole sensor rather than the cell, which gives a reliable result and the correct radio profile. Every replacement needs a relearn afterwards so the car knows which sensor sits at which wheel, done either through the diagnostic port or a set drive pattern. Costs vary by car, but as a guide:
| Job | Typical cost |
|---|---|
| Sensor replacement | £60 to £120 per wheel, fitted |
| Valve stem only | £15 to £25 each |
| Module reprogramming | £50 to £80 |
| Complex wiring or ECU work | Add £100 to £200 by diagnostic time |
Why a working TPMS is worth having
Beyond clearing a warning light, a healthy system earns its keep. It catches dangerous underinflation before it causes a blowout or poor braking, and correct pressures cut rolling resistance for a small fuel saving and noticeably longer, more even tyre wear. Tyre pressure monitoring has been fitted to new cars for over a decade now and is checked as part of the MOT, so a failed system is an MOT issue as well as a safety one. It matters even more on the heavier electric cars, where the right pressures protect your range.
TPMS help across Luton and beyond
We are on Dudley Street in Luton and look after drivers across Luton and Bedfordshire for TPMS diagnostics and sensor work, with quality parts and a proper relearn every time.
TPMS questions we hear a lot
How do I reset the TPMS light at home? Inflate all tyres to the correct pressure, then use the reset button or dashboard menu and drive to complete the relearn. If it stays on, a sensor likely needs attention.
Can I replace a sensor battery myself? No, the batteries are sealed into the sensor. We fit a preprogrammed replacement instead, which avoids seal and calibration problems.
How much does a sensor cost? Usually £60 to £120 per wheel fitted, depending on the sensor and programming.
How do I know a sensor is faulty? A warning light that stays on after correcting pressures, readings that jump around, or a sensor missing on a diagnostic scan all point to it.
When should I see a professional? When several sensors fail at once, a module needs reprogramming, or aftermarket sensors need matching to the car.
How do I book? Use the booking button below any time, or give us a call.
