Can a bad speed sensor cause auto transmission to jerk when shifting and check engine light to come on?

Yes, a faulty speed sensor can cause an automatic transmission to jerk during shifting, as it provides critical data for the transmission control module to manage gear changes smoothly. When the sensor malfunctions, the transmission may receive incorrect information, resulting in erratic shifting patterns. Additionally, a bad speed sensor can trigger the check engine light, as the vehicle's diagnostic system detects the discrepancy in speed readings. It's advisable to have the sensor checked and replaced if necessary to ensure proper vehicle performance.