Tire Pressure Monitoring Systems are a safety feature to alert the driver of a tire pressure difference.
In most cases a tire would have to lose about 25% of its specified pressure before it alerts. Where it is most useful is while driving, since it would be hard to check the pressure when you are behind the wheel.
Often misunderstood
Every manufacturer has their own way of dealing with these systems, some use sensors mounted in the wheels, we call them; “Direct Tire Pressure Monitoring Systems”. Direct sensors have batteries in them that are not changeable, and eventually will fail. Others use the already equipped ABS (Anti Lock Brake System) to monitor the speed of each wheel in order to determine if a tire has gone low; we call this system, “Indirect Tire Pressure Monitoring Systems”.
To you both systems will look the same. Below is a Direct system with a sensor which is mounted just behind the valve stem.
Direct tire pressure monitor system.
It doesn’t matter which system is being used, what matters is that pesky light stays off of the dash, and your tires are properly inflated. Since it is stressful when a warning light pops up while you are driving down the road.
Technical expertise
It takes a box of tools to deal with each system. Direct systems have multiple operating frequencies and parameters, while Indirect systems will require re-calibration every time work has been performed to the tire and wheel systems. Scan tools and a party of “TPMS” tools are required; plus the ability to persevere through the workflow of each specific system in order to understand the proper way of calibrating or, “re-learning”.
Some Tire pressure monitor systems require a 40km drive in order to be properly re-set. These systems will turn the light on usually a day after the tires have been worked on. The system is set into “learn mode”, then, if the vehicle has not gone through its correct drive cycle, the warning light will come on.
TPMS light on?
Check the tire pressures. You can easily locate proper inflation specifications on the sticker just inside the driver’s door frame; adjust as necessary. It looks like this;
Typical location of tire specification placard.
Close up of typical tire specification placard
Tire light flashing?
If Tire pressure warning light is flashing, this usually indicates a malfunction within the system somewhere. Most of the time it loses signal from one of the sensors, and wants you to know about it so the system will flash the light.
Sensor Cloning?
There won’t be any nuclear transferring of cells when we clone, but it is still pretty cool! However, when we supply new wheels and tire pressure sensors, we use a sensor which can be cloned. Cloning allows us to write the same sensor ID’s into the new sensor as what was already stored in the computer. This allows for the ease of wheel swaps without having to “re-learn” the system, since the computer will not know the difference.
This fall season we have done hundreds of sets tires and wheels, most equipped with Tire Pressure Monitoring Systems. It keeps us sharp and as efficient at re-setting them as possible. If only they were a standard system…
Are you cruising around with your tire pressure light on? We can help!