There are 3 main types of TPM sensor mounting arrangement to the wheel rim.
Schrader based TPM electronics with a pull through fitting which needs no special equipment to install other than a standard rubber stem puller. The EZ-sensor® for example is a snap fit TPMS Sensor:
Most popular type of fitting adopted by most manufacturers. Usually requires a dynamic programmable torque wrench or torque profiling gun to mount. Additionally, may also require a mounting jig to assist with the installation and ensure the parts are fitted at the correct angle and a good seal is formed without breakage. Some manufacturers specify a particular torque profile and torquing process be applied to ensure a good residual torque.
Only used by Ford and now superseded however, still found on original fitments on many manufactured Ford vehicles. The TPMS sits on the rim centre and is opposite the valve stem, held in place with a steel band.
A Tire Pressure Sensor may be replaced for a number of reasons, faulty or damaged sensor, replacement wheels or tyres (winter tyres, custom wheels etc) and so on. The first step should be to use a TPMS tool to audit the vehicle and diagnose any problems such as faulty sensor battery, blocked pressure port, or simply faulty sensor.
When removing the tyre from the wheel the technician should be careful where the tyre removal blade is positioned so as not to damage the sensor. The correct replacement part should also be ensured as the sensors from different manufacturers look alike and are easily confused.