Bathwick Tyres

Understanding TPMS

TPMS (Tyre Pressure Monitoring System) is to alert you when tyre pressure is too low and could to create unsafe driving conditions. If the light is illuminated, it means your tyres could be underinflated, which can lead to undue tyre wear and possible tyre failure. It's important to understand the importance of proper tyre inflation, and how TPMS can help you maintain your tyres.

Maintaining proper tyre inflation is essential to vehicle handling, overall tyre performance, and load carrying capability. A properly inflated tyre will reduce tread movement, reduce rolling resistance, and increase water dispersion. Reduced tread movement gives the tyre a longer tread life. Reduced rolling resistance, the force required to roll a loaded tyre, results in increased fuel efficiency. Increased water dispersion decreases the possibility of hydroplaning.

In most sensors there is a lithium battery with an expected life of 8-10 years.

OEM sensors are designed to last approx 8-10 years under normal conditions. Temperature / climate can affect this.

Underinflation can cause premature treadwear and possible tyre failure. Overinflation can result in decreased traction, premature wear, and the inability to absorb road impact. Overinflated tyres will show premature wear in the center of the tread. On the other hand, underinflation will cause sluggish tyre response, decreased fuel economy, excessive heat buildup, and tyre overload. An underinflated tyre will show premature wear on both outside shoulders.

The TPMS warning light will help warn you when your tyre pressure is too low. Your TPMS has various illumination patterns that mean different things. Keep reading to find out what they mean.

If you’re learning about tyre pressure sensors for the first time, finding the TPMS indicator on your dashboard is simple. It’s a horseshoe-shaped light with an exclamation point in the center.

The LAW in Europe

  • Commission Directive 2010/48EC confirmed that from November 2012 all new TYPE Approved M1 vehicles will be required by law to have a tyre pressure monitoring system installed.
  • From November 2014, all newly registered M1 Vehicles in the EU need to have a TPMS installed.
  • TPMS is part of the European National Car test, for all newly registered cars from January 1st, 2012.
  • A car with faulty TPMS will fail from January 2015/6.

Different TPMS

  • Indirect – No sensors installed in wheels
  • Direct – Sensors installed in each wheel

Indirect tyre pressure monitoring systems measure the rotational speeds diagonally of each tyre.

An under-inflated tyre will rotate slower than the correctly inflated one, giving a tyre pressure warning.

Peugeot and Citroen will fit indirect TPMS to some low-end models.

Honda VW and Audi will fit indirect TPMS on most models.

Must use tyres specified by the manufacturer.

Most sensor manufacturers believe that indirect TPMS will not be a popular option for the consumer.

It’s not accurate, it needs to be re-calibrated by the driver after inflation, wheel rotation or tyre replacement...

We are told that DIRECT TPMS will be compulsory in 2016.

Each wheel of the vehicle has a sensor fixed to it to monitor the changes in pressure and temperature from the tyre.

If low pressure or a leak is detected (20% less than operating pressure) the driver is alerted by the in-car system.

Direct TPMS monitors tyre pressure to 1.5 kpa. It’s very accurate.

  • Sensors send their signal approximately every 30 seconds whilst driving. Low pressure will be identified very quickly.
  • Tyre sensors can identify leaking air.
  • At start up a tyre with low pressure is immediately identified.
  • The underinflated tyre is identified.

Sensors need to be serviced each time a tyre is replaced to maximize their service life.

We Service the Sensor to...

  • To create a good airtight seal - Rubber Gromm.
  • To ensure corrosion on the valve body is minimiz.
  • To replace metal fatigued parts - Outer Coll.
  • To replace the valve core to ensure that the valve is internally airtight – Nickle plated.

The sensor is serviced by replacing the outer collar, the dust cap, the rubber seal, (the washer), and the valve.

Inspection is Important

Relearn Process

Some vehicles Auto learn new sensors, or relearn current sensors if the wheel positions are changed…. BMW, Mercedes, Landrover, Jaguar and others

Some vehicles need to have the ID’s of new sensors registering to the ECU via the OBDII connection or the position of the wheels is changed….... Peugeot, Citroen, Renault, Toyota, Lexus and others...