eli5: Why do you need to “Drive 50 miles” to reset the sensors in a car?

Question

eli5: Why do you need to “Drive 50 miles” to reset the sensors in a car?

In: 1

Answer 1

Well the sensors themselves aren’t reset, it’s the data the sensors take that needs validated.

When you disconnect the battery (or replace a bad sensor with a new one) the car has no idea if it can trust the sensor readings, and it needs real world data to validate against.

Note that “drive 50 miles” is just an estimate that is likely to hit all the needed data points.

Many manufacturers will publish an actual “drive cycle” that can be run to get the needed data for all of it’s sensors faster. Something like start car from cold and between 1/4 and 3/4 tank of gas, idle for 5 minutes, drive at a constant rate of 30mph for 5 minutes, drive at > 60mph for 5 minutes, let car engine cool below 130 F, repeat.