Schrader Academy



What is TPMS?
A tire pressure monitoring system or TPMS is an electronic system for monitoring the air pressure in a vehicle tire and automatically transmitting a warning to the driver in the event of an under and, in some cases, over–inflated tire. These systems have been legislated to be progressively installed on all new passenger carrying US and EU vehicles and similar legislation is being introduced worldwide.
What are the benefits of TPMS?
- TPMS keeps you safe - Safety studies show that an estimaged 250,000 vehicle crashes are caused by underinflated tires each year, nearly 700 crashes each day (NETSA).
- TPMS can save you money - Not only can underinflated tires reduce the life of your tires, it can also cost you at the pump!
- Properly inflated tires save the typical passenger car 9.32 gallons of fuel, every year (NETSA).
- TPMS helps your car perform - Proper tire pressure improves the way rubber meets the road by optimizing traction, handling, steering, stability, braking and even the life of your tires.
- TPMS reduces CO2 emissions - Properly inflated tires improve gas mileage. The gallons you save will translate to reduced carbon emission from your vehicle!


What is the North American TPMS Legislation?
On November 1st 2000, US Congress enacted the TREAD Act (Transportation Recall Enhancement, Accountability, and Documentation). It requires passenger cars, multi-purpose passenger vehicles, trucks, and buses with a gross vehicle weight rating (GVWR) of 10,000 lbs (4,536 kg) or less, to be equipped with TPMS to alert the driver when one or more of the vehicle’s tires, is significantly under-inflated.

Implementation of these new standards were applied in phases:
- 20% of new vehicles by October 2005
- 70% of new vehicles by September 2006
- 100% of new vehicles by September 2007


What is the difference between direct and indirect TPMS?
• Direct TPMS has a sensor installed in the wheel and tire assembly. This sensor detects what the actual tire pressure is in each of the tires.
• Indirect TPMS does not have a sensor installed in the wheel and tire assembly. This system detects the low tire by comparing relative wheel speeds via the Anti-lock Brake System (ABS). When a tire loses air, its diameter decreases slightly. One drawback is the inability to read the tire pressure when the vehicle is sitting still.
What is the difference between programmable and OE Replacement TPMS sensors?
OE Replacement sensors are supplied with a with a single vehicle protocol, while programmable sensors can be programmed using a TPMS programming tool to specific make, model, year.
What are benefits of universal/programmable sensors?
Universal/programmable sensors are designed to replace the original equipment (OE) sensors for the automotive aftermarket. Main benefits of programmable sensors are:
•    Lower stock volumes and cost associated to it
•    Simplified TPMS fitment, diagnostics, part selection and fitment
•    Lower the risk of fitting the wrong part
•    Increased speed of service
•    Avoid lost sales from not having the right part
•    Sensors can be programmed either before or after the wheels are mounted to the vehicle
What is the difference between programming and relearning?
EZ-sensor® comes BLANK and must be programmed to the specific MMY of the vehicle being serviced using a compatible TPMS programming tool. The tool programs the sensor with the vehicle specific protocol so that the sensor can communicate with the vehicle’s receiver. After the EZ-sensor® is programmed, it functions the same way as the OE sensor for that specific vehicle. A relearn is required any time a NEW sensor ID is introduced to the vehicle or when the tires are rotated. The vehicle’s ECU records the 4 (or 5) sensor IDs so that:
• The unique IDs installed on the vehicle are correctly recognized by the vehicle’s ECU.
• On vehicles with pressure by location, the ECU can display the correct wheel location of each tire’s pressure.

Replacing a Sensor/Maintenance

What does the TPMS light mean?
Solid light
•    If the TPMS light comes on and stays solid, it indicates one or more tires has low air pressure. Some vehicles provide a visual of each tire’s pressure and may or may not also include the TPMS symbol.
•    During service, the tires should be inspected and inflated to the recommended tire pressure.

Flashing light
•    If the TPMS light comes on and flashes for 60 - 90 seconds before staying solid, it indicates a system malfunction.
•    During service, a test should be performed to determine the cause of failure and a repair solution must be provided.
Why is it important to change the service kit every time the tire is removed from the wheel?
Harsh road conditions such as salt, sand, dirt and road grime may cause valve cores and aluminium stems to corrode, causing potential air leaks. Time and environmental elements could cause rubber stems to crack, also causing slow air leaks. Changing the service kit is a simple, inexpensive way to help ensure that your TPMS services are compliant and may decrease returns.
How do I find out what the recommended tire pressure is?
On the driver’s side door, there is a sticker, called a “placard”, on the front end of the frame. This door placard shows the manufacturer’s recommended tire pressure for the specific vehicle. A common mistake people make is to fill tires to the “max air” pressure shown on the sidewall of the tire, which is incorrect. The tires should be filled to the door placard pressure. 
How often should the tire pressure be checked?
It is recommended that the tire pressure should be checked once a month. It is important to check tire pressure in the morning before driving the car. This will ensure the air in the tire has not expanded from heat and will provide the most accurate reading.