Reverse parking sensors are a fantastic safety feature that have been added to many cars and trucks in the last few years by auto manufacturers. These sensors use radio waves to detect if there is an object in the direction of the vehicle, and within a certain distance of the vehicle. These objects could be a trash can, a bicycle, or a child. As the vehicle backs up, when there is an object that has been detected, an alarm will get progressively louder and more frequent depending on how close the object is. This is particularly useful in vehicles that have a large blind spot or that have poor visibility around the car. Occasionally these sensors fail, and it is necessary to replace them. For many types of vehicles, this is a simple car DIY that can be done in an hour or two.
Step 1 - Determine the Faulty Sensor
First, determine which are the faulty reverse parking sensors. Put the vehicle in reverse (no need to start it), and put the emergency brake on. Run your fingers along each of the sensors on the rear bumper. If they are active and working, they will emit a subtle buzzing or ticking that you will feel. If there is a sensor, or several, on which you do not feel the buzzing or clicking, these are the bad sensors that need replacement.
Step 2 - Remove Faulty Sensors
The removal and replacement of your sensors will depend largely on the type of sensors that you have installed on your vehicle. There are a variety of types, but those that are the most common rely either on an antenna to communicate to the control box and alarm, and those that are wired directly into the vehicle's electrical system.
If possible, familiarize yourself with what you have prior to starting the project, so that you will know what type of sensors to obtain. Most sensors are mounted in the rear bumper cover and are wired into the vehicle. In some circumstances, removing the bumper cover is required to remove and replace damaged sensors and their components. Generally, sensors are fitted into several different openings in the bumper. Simply remove the fittings and slide the sensor out. Take care not to break or damage any fittings, as you will need them when replacing with the new sensors.
Step 3 - Replace Sensors
Inspect the sensors to see how they are wired, and if the wiring can be disconnected at the sensor and a new sensor attached. If not, you will have to trace the wiring back into the vehicle and to the control box, disconnecting it from the control box. Pull the wiring for the old sensor out, and fish the wiring for the new sensor through the body to the control box. Connect the new wiring. Insert the sensor into the bumper cover, and secure it with the old fittings.