Parking Sensor Fault Finding (Troubleshooting + Quick Fix)

parking sensor fault finding

Have you ever wondered why your parking sensors are not working and how to fix them? Well, we got you covered.

Parking sensors have become an indispensable feature in modern vehicles, providing drivers with invaluable assistance in tight parking spots and alerting them to potential obstacles while reversing.

However, like any other technology, parking sensors are not immune to malfunctions and issues. In this comprehensive guide, we discuss the various causes of parking sensor problems and provide expert advice on how to diagnose and troubleshoot them effectively.

Parking sensors are electronic devices that use ultrasonic or electromagnetic waves to detect objects in close proximity to the vehicle. They are typically installed on the front and rear bumpers, providing audible and visual alerts to the driver when an obstacle is detected.

Parking sensors have become a standard feature in many car models, significantly improving parking safety and reducing the risk of collisions.

Common Causes of Parking Sensor Problems

There are several reasons why parking sensors may malfunction or stop working altogether. Some of the most common causes include:

  1. Dirt and debris: Accumulated dirt, dust, or debris on the sensor surface can obstruct its functioning and lead to false readings or no readings at all.
  2. Moisture and corrosion: Exposure to moisture can cause corrosion in the sensor’s metal housing or electrical connections, resulting in malfunctions.
  3. Electrical faults: Faulty wiring, damaged connectors, or problems with the control module can disrupt the proper functioning of parking sensors.
  4. Physical damage: Impacts or collisions can damage the sensors or their housing, rendering them ineffective.

How to Clean Parking Sensors

Dirty sensors are one of the most common causes of parking sensor problems. Follow these steps to clean them properly:

  1. Locate the parking sensors on your vehicle’s front and rear bumpers.
  2. Use a soft, damp cloth or microfiber cloth to gently wipe the sensor surfaces, removing any dirt, dust, or debris.
  3. If the sensors are still not functioning correctly, remove them from their housings according to the manufacturer’s instructions. Be sure to consult your vehicle’s owner’s manual for guidance.
  4. Clean the sensor housings using a cloth dampened with a mild detergent solution. If necessary, apply a water-displacing spray like WD-40 to prevent rust formation.
  5. Reinstall the sensors, ensuring they are securely fitted and properly aligned.

Testing Parking Sensors with an OBD Tool

An Onboard Diagnostic (OBD) Tool is a useful device for identifying and troubleshooting vehicle-related issues, including parking sensor problems. To test your parking sensors using an OBD tool, follow these steps:

  1. Locate the Diagnostic Link Connector (DLC) in your vehicle. Refer to your owner’s manual for the exact location.
  2. Connect the OBD scanner to the DLC and turn on your vehicle’s ignition.
  3. Select your vehicle’s make, model, and year on the OBD tool, then navigate to the Parking Aid Module (PAM) section.
  4. Initiate a scan, and the tool will display any fault codes related to the parking sensors. These codes can help you identify which sensor is malfunctioning and the nature of the issue.
  5. Replace any faulty sensors as needed, then clear the fault memory using the OBD tool to remove old errors.

Testing Parking Sensors with a Multimeter

If you don’t have access to an OBD tool, you can use a multimeter to check the functionality of your parking sensors. Follow these steps:

  1. Safely raise your vehicle using jack stands or ramps to access the sensors on the bumper.
  2. Locate and carefully remove the sensors from their housings, disconnecting them from their sockets.
  3. Identify the pins inside the sensor socket. Most three-wire sensors have a triangular arrangement with a negative pin at the top and a positive pin at the bottom right.
  4. Set your multimeter to the 20k Ohms resistance setting. Touch the red probe to the positive pin and the black probe to the negative pin of the sensor.
  5. A functioning sensor should give a reading of 500 ohms or higher. If the reading is lower or nonexistent, the sensor is likely faulty and should be replaced.
  6. Repeat this process for all sensors, replacing any that are not functioning correctly.

Resetting Parking Sensors

In some cases, resetting the parking sensors can resolve minor issues and restore their functionality. To reset your parking sensors, follow these steps:

  1. Park your vehicle on a level surface and ensure the engine is off.
  2. Locate the parking sensor control unit, typically near the front or rear bumper.
  3. Press and hold the “reset” button on the control unit for approximately five seconds.
  4. Start your vehicle and check if the parking sensors are now working correctly.

Replacing Faulty Parking Sensors

If your parking sensors are damaged or malfunctioning, you may need to replace them. Here’s how:

  1. Purchase replacement sensors compatible with your vehicle make and model.
  2. Follow the steps outlined in the “Testing Parking Sensors with a Multimeter” section to safely remove the faulty sensors.
  3. Connect the new sensors to their sockets and reinstall them securely in their housings.
  4. Test the new sensors to ensure they are functioning correctly.

Common Parking Sensor Errors and Fixes

Here are some common parking sensor errors and their potential fixes:

  1. Sensors not beeping: Check for dirt or debris obstructing the sensors and clean them as needed. If the issue persists, test the wiring and replace any faulty sensors.
  2. Sensors beeping constantly: Inspect the sensors for physical damage or obstructions and address any issues. If the problem continues, consult a professional for further diagnosis.
  3. Sensors activating when not in reverse: This may indicate a fault with the reverse switch or the sensor’s control module. Consult your owner’s manual for guidance or seek professional assistance.

Read also >> How to Fix Parking Aid Malfunction (Helpful Tips)

Read also >> Park Pilot Malfunction (Causes, Solutions + Prevention)

Read also >> BMW Parking Lamp Malfunction (Here Is How To Fix)

Maintenance Tips for Parking Sensors

To prolong the life of your parking sensors and ensure their optimal performance, follow these maintenance tips:

  1. Regularly clean the sensors and their housings to prevent dirt and debris buildup.
  2. Inspect the wiring and connectors for any signs of damage or corrosion, addressing any issues promptly.
  3. Avoid using high-pressure water jets or abrasive cleaning materials on the sensors, as this can cause damage.
  4. Schedule routine check-ups with a professional mechanic to diagnose potential issues early on.

How do you test a parking sensor?

ADAS technologies require real-world testing with high-end data acquisition hardware and software that can be installed in vehicles to precisely time-align data from multiple test vehicles.

Ultrasonic park assist sensors are used to control park assist in vehicles and may require calibration or aiming after impact.

Test tracks and equipment, sensors, and autonomous testing tools like driving robots, GPS/GNSS, IMU and INS sensors, high-speed wireless car-to-car and car-to-base data networking, and ADAS targets are also essential for complex testing involving multiple vehicles and objects under a staggering number of possible conditions.

Do parking sensors need calibration?

Yes, parking sensors may need calibration or aiming after impact, removal of the bumper cover or the sensor itself, or during replacement. Typically, removing or replacing parking assistance sensors requires initialization, azimuth test, verification, or calibration, depending on the make and model of the vehicle.

Calibration and aiming involve using high-end data acquisition hardware and software, as well as ultrasonic park assist sensors. These processes are vital to ensure that the parking sensors are working correctly and accurately detecting obstacles.

Advanced driver assistance systems (ADAS) such as parking assistance often require post-repair calibrations. For complex testing of ADAS technologies, test tracks and equipment, autonomous testing tools like driving robots, GPS/GNSS, IMU and INS sensors, high-speed wireless car-to-car and car-to-base data networking, and ADAS targets are essential.

How long does it take to fix parking sensors?

The time required to fix parking sensors can vary depending on the specific calibration requirements. However, the process of testing parking sensors involves high-end data acquisition hardware and software, ultrasonic park assist sensors, and autonomous testing tools.

Calibration and aiming may be necessary after impact, removal, or replacement of the sensors. Post-repair calibrations are often required for ADAS technologies like parking assistance.

Why is my parking sensor beeping for no reason?

There are several reasons why parking sensors may beep for no apparent reason. Some common causes include system errors, dirty or obstructed sensors, damaged sensors, and wiring issues.

If you have already replaced a faulty sensor and the new sensor is still giving a constant warning even when there are no objects nearby, calibration may be necessary.

Do parking sensors have a fuse?

Yes, parking sensors have a fuse. The parking sensor fuse is typically located in the fuse box under the steering column or in the engine compartment. However, it’s worth noting that parking sensors generally don’t require fuses, or are fused as part of the larger vehicle system.

If you’re experiencing issues with your parking sensor, such as beeping for no reason, it could be due to a variety of factors, including system errors, dirty or obstructed sensors, wiring issues, or calibration requirements.

Parking Sensors Not Working Try This! How To Diagnose and Troubleshoot >> Check out the video below:


Parking sensor problems can range from minor issues like dirt accumulation to more severe faults involving the control module or wiring.

Understanding the common causes of parking sensor malfunctions and how to diagnose and troubleshoot them can save you time, money, and frustration.

By following the tips and guidance provided in this comprehensive guide, you can ensure the longevity and reliability of your parking sensors, enhancing the safety and convenience of your driving experience.

Steve P.

Steve is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Riviera. Steve is based in Boise, Idaho.

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