What is code b1238 on a Chrysler 300c and how do you fix it?

PTS Sensor 9 Ring Time Too Short. The problem is with the Park Assist Sensor #9. The numbering system for the park assist sensors allows for up to twelve sensors on the

vehicle, six front and six rear. The sensors are numbered in a clockwise manner starting at the

left front bumper. The left front sensor (if equipped with front park assist) is the number 1

sensor. The numbering continues in a clockwise direction around the vehicle. Since Chrysler

LLC vehicles use only four rear sensors, sensor numbers 7 and 12 are omitted, so the left rear

sensor is the number 11 sensor.