Final answer:
No, it is not always necessary to perform a relearn every time a tire is rotated or a sensor is replaced, as it depends on the vehicle's specific TPMS technology and the make and model of the vehicle.
Step-by-step explanation:
The question 'Do you have to perform a relearn every time a tire is rotated or a sensor is replaced?' pertains to the process involved with maintaining Tire Pressure Monitoring Systems (TPMS) in vehicles. When a tire is rotated or a sensor is replaced in a vehicle that uses a direct TPMS with sensors that provide feedback on the specific location of each tire, a relearn process is generally necessary. This relearn process allows the vehicle's TPMS to correctly identify the location of each tire. The need for a relearn, however, can vary depending on the make and model of the vehicle, as well as the type of TPMS used. Some vehicles have systems that automatically relearn sensor positions after a rotation or new sensor installation, while others may require a manual relearn process or a reset using specialized tools. Therefore, the answer to the question is: No, a relearn is not always necessary every single time, but it depends on the vehicle specifications.