About Tyre Pressure Monitoring system's

What is TPMS?

TPMS stands for Tyre Pressure Monitoring System and EU legislation now requires that all newly approved vehicles must be fitted with TPMS, this has been standard since November 2012. In it’s simplest terms, either: Sensors are fitted to the air valve within each wheel, reporting tyre pressures to the vehicle ECU (DIRECT TPMS) or The vehicle utilises it’s other sensors (ABS) to approximate the air pressure that is in the tyres (INDIRECT TPMS). Vehicles fitted with TPMS as standard AND first used / registered on or after January 1st 2012 will have their TPMS system tested as part of the MOT road worthiness test from 2015 onwards.

Why Do Direct TPMS Sensors Need Servicing?

Tyre Pressure Sensors are relatively expensive pieces of technology where tyres are concerned, in some instances costing over £100 per unit for the OE product. Ideally, the only time a sensor should need to be replaced is when the internal battery runs flat. However, due to environmental weathering and sometimes galvanic corrosion of some of the components fastening the valve to your wheel and sealing the valve air tight, TPMS valves can become faulty or fail completely. A simple and considerably cheaper solution is to keep the valve in good condition through servicing, replacing the old components with a brand new set.

Servicing of TPMS Sensors every time the tyre bead is broken is considered a standard requirement by sensor manufacturers in order for them to last a full lifetime.

Why Do TPMS Sensors Need Replacing?

In ideal circumstances, sensors generally require replacement once the internal battery has died. Realistically, battery life of each sensor can be anything between 3 & 7 years, or around 100k-150k miles. The internal battery of a sensor is in use at all times but at varying levels, with minimal use whilst the vehicle is stationary, normal use when the vehicle is moving and heavy use if the TPMS system is in alert mode due to low tyre pressure or puncture detection (warning light on dashboard). Unfortunately, due to incorrect handling or neglect of servicing, sensors and sensor components can also break which in some cases may require a complete sensor replacement.

What Is An Electronic Reset & Will I Need One?

When new sensors are fitted to a vehicle it is important that they are paired to the ECU (the car’s brain). This process is also a requirement after wheel rotation, as the sensors need to be relocated within the ECU. With OE sensors this means there may be some type of reset that needs to be performed, which may require the car to be driven for a certain amount of time at a minimum speed, or it may need some specialist equipment to be connected to the vehicle. Any resets that are performed by us may incur an additional charge.

We Are Looking After Your TPMS System Servicing & Replacing Your Sensors!

TPMS Cap

The first line of defence against contaminants entering the valve system. Ideally plastic to avoid corrosion.

TPMS Core

Nickel plated core, NEVER BRASS in aluminium stemmed sensor valves.• Allows tyre to be inflated, seals upon release. Should always be torque tightened.

Hex Nut

Used to tighten the valve to the wheel. Look out for corrosion which may make removal difficult. Should always be torque tightened.

Washers

Aids the seal between the rim & the sensor valve. Always fit correct washer(s).

Valve Stem

Attached to the sensor body. Allows access in order to inflate / deflate the tyre. Can be damaged when using incompatible valve caps, usually chrome. Can be damaged when inflating tyre with rigid inflation gauges. Sometimes the valve stem can be replaced, but not always. Look out for corrosion.

Rubber Seals / Grommets

• Additional seal between the rim & the sensor valve.

• Fastened under torque & deteriorates over time, similar to rubber valves.

Sensor Body

An electronic device transmitting: Tyre Pressure Tyre Air Temperature Battery Status Unique ID Number. Some or all of these data fields are captured by the vehicle ECU to report low pressure / punctures to the driver. Battery is not replaceable but usually lasts between 3-5 years dependent on use of vehicle / miles travelled.

Screw

Holds replaceable stems in place. Should always be torque tightened.