The backup sensor is out, and my car rapidly beeps when in reverse.
The rapid beeps are actually an indication of which sensor is out. If the beeps are rapid and non-stop it is probably the right side sensor that needs replacing. The right rear sensor also makes many beeps but will typically stop after 9 beeps or so. A mechanic should be able to test the signal of the sensors to determine if they are working properly and which are in need of replacement. If you need further assistance or an in-person inspection, consider the services of YourMechanic to help you out with this.
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