Explanation of TPMS sensors
TMPS Sensors seem to be a hot topic as of late and are confusing everyone…..hopefully this will clear up the confusion. The first thing to understand is that each TPMS sensor contains two pieces of information that is relayed to a vehicles computer. The Protocol – essentially the frequency and language and perhaps a tire pressure threshold required for the sensor to communicate with the year, make, and model of vehicle. And the Serial ID number – the computer stores the ID number of each sensor in a location for the LF, RF, RR, LR and sometimes for the spare so that if one of the sensors starts talking to the computer because the pressure is low … the computer knows which tire it is.
The Re-Learn procedure on each specific vehicle is how the vehicles computer is reset and then signaled to re-learn the ID numbers for the various positions ( LF, RF, RR, LR and spare ). This is what is done if you rotate the tires.
Once in re-learn mode some vehicles will do this automatically when you drive and others will not . Some you have to let the air out of the tire to breach the threshold in order to cause the sensor to go off and send info to the computer. Another method was to “activate” the sensor with a tool.
The first generation of TPMS tool was simply a magnet that would “activate” the sensor so that a computer in relearn mode would pick up this signal and store the information. The sensors sit dormant until a low pressure situation occurs. If they did not the battery would run out very quickly and very frequently. These sensors did not have ID numbers so you did not know which tire was low, just that you had a low tire.
As sensors were modified and different manufacturers came up with their own frequencies and technologies magnets were no longer capable of “activating” the most of the sensors.
Additionally Serial ID numbers were introduced. The second generation of TPMS tool allowed you to identify a vehicle by a code that was entered into the machine. This code told it what “protocol” to use. These tools dramatically reduced the amount of time involved with a re-learn because once the vehicle was in re-learn mode you could walk around the vehicle and use the tool to “activate” the sensor so that the computer would pick up the information without mucking with the air pressure or going for a drive.
The technology keeps on evolving and it is a challenge to keep everything straight. There are now many different manufacturers and tools are on the market and they do not always work well with each other. They have been on every vehicle since 2008 and now the batteries are starting to fail. Vehicles owners do not want to see that TPMS light on.
OE replacement sensors contain protocol and id numbers that cannot be changed. When you install new sensors in a vehicle you must always perform an OE relearn on the vehicle so that the computer will pick up the new serial numbers and associate them with the location on the vehicle. Problem is that there are several vehicle makes and you end up having to stock hundreds of part numbers to cover them all, Aftermarket Sensors have added features that allow for suppliers to stock fewer numbers, have better vehicle coverage, and deal with winter and summer tire situations.
VDO make a sensor called a Redi- Sensor that is loaded with multiple protocols. They have several vehicle’s information stored on the sensor and when you punch the vehicle year, make and model into the tool and “activate” the sensor, it will transmit what the vehicle’s computer wants to pick up when in re-learn mode.
Then next generation of sensors are ones that allow you to also Clone the Serial ID number. Revolutionary !
Cloning allows you to create,change, or make the ID Serial Number on two sensors identical so that when you put the LF winter tire on and take the LF summer tire off, you do not need to perform a relearn to the vehicles computer….. unless you rotate the tires. This is because “if cloned” the ID numbers the computer sees are identical on both tires. Some people confuse the ability to program to different protocols with cloning.
The serial number of the sensor located on the LF, RF, RR, and LR is what is stored in the vehicles computer at those positions. When a sensor starts signaling the computer that the tire pressure is low, the computer identifies the ID Serial Number stored in the LF position on the computer and tells you the LF tire is low. If you move the LF tire to the LR ( tire rotation ) without telling the computer … when that sensor starts signalling low tire the computer still thinks that Serial number is located at the LF…. When that sensor is actually now on the LR. This is why re-learns are required.
Schrader make OE sensors but they also make a sensor called an EZ-Sensor. This sensor contains NO PROTOCOL and an ID number. These sensors utilize the expensive TPMS tools on the market ( i.e. Bartec 400SD , ATEQ, Snap-On ) to “program” the sensor with whatever “protocol” that you want based on Vehicle make and model. The EZ-Sensor had an added feature in that it utilized a rubber valve stem very similar to the traditional valve stem to secure the sensor to the rim. This EZ-Sensor allowed tire shops to stock 1 part number that could be turned into almost anything and use the preferred rubber stem in any set of winter rims. These sensors are also clone-able but utilize some of the more expensive TPMS tools on the market.
We now Carry the Standard Line of TPMS Sensors — they offer two versions of the next generation of sensor technology – we stock them both.
First is the OE Clone-able Style sensor
- TPMS from the leader in vehicle sensor technology – full Design, Manufacture, Marketing, Sales, & Technical Support
- Full program includes TPMS sensors, service kits, accessories, mounting hardware, and the right TPMS tools
- Engineered to match OE fit, form and function, Standard OE Clone-able sensors are ready-to-install and can be OE-relearned
- Standard TPMS sensors are designed to operate within an extremely tight radio frequency (RF) eliminating most external interference for a more accurate monitoring of the tires, Each sensor comes with its own unique ID Serial Number and uses the exact OE protocol to ensure reliable performance
- Equipped with Advanced ID “Cloning” technology, Standard OE-matching Clone-able TPMS sensors were a New Product Showcase Winner at AAPEX 2012
- Technicians can now bypass complex OE relearn processes by cloning the sensor ID Serial Number – saving time and money while maintaining OE fit, form and function
- Standard Clone-able sensors can be used with all OE and aftermarket TPMS programming tools if performing an OE relearn – simple activation.
- Clone-able sensors can be ID-cloned manually with the TechSmart® T55000 tool or using RF transmission with our T55001 and T55003 tools.
- 187 total part numbers including a broad service line of compatible valve cores, valve nuts, seals, washers and valve caps
- 122 total OE-matching TPMS sensors with more than 98% coverage for domestic and import vehicles
- 62 Clone-able sensors with 85% coverage for domestic and import vehicles
- 24 out of the top 25 OE-matching sensors are clone-able
These are sensor part numbers starting with TPM.
Second – Discover the new QWIK-SENSOR™ advantage
- Three sensors ( Domestic, Asian, and European ) provide 94% coverage.
- Available in two valve stem configurations on each sensor, rubber or metal, to match the proper application. So three sensors with two valve stem configurations equals 6 part numbers.
- All QWIK-SENSOR™ sensors come fully assembled from the factory but need to be programmed prior to install.
- Color-coded for easy identification Programmed with TechSmart® tools
- ID clone-able or can be OE-relearned once programmed.
- Currently Standard TechSmart® T55001 and T55003 tools, ATEQ tools , “High End” Snap-On tools, and Bartec 400SD ( needs Update Version 52 ) can program sensors.
These are sensor numbers starting with QS.