1999 Mercury Tracer 4 cyl Two Wheel Drive Automatic 110000 miles
About once a week the car will JOLT / JERK like you tapped hard on the brakes. Then the check engine soon light comes on and stays light until the computer is cleared.
The code the scanner displays, is a speed sensor code. The speedometer seems to work fine and we have never noticed it " drift" or not working. If the speed sensor is defective, why is the car jerking like this when the check engine light comes on?