OBD Codes

B0181

Parking Sensor Circuit Malfunction - Rear

Lowsensor

About B0181

The B0181 diagnostic trouble code indicates that the body control module has identified a parking sensor circuit malfunction - rear issue. This code means a body sensor or its circuit is not providing expected readings. Accurate sensor data is important for proper operation of safety and convenience systems throughout the vehicle. This guide covers everything you need to know about this topic, including common causes, step-by-step solutions, and answers to frequently asked questions.

Here are the key things to understand: Window pinch protection not functioning. Parking sensors not detecting obstacles. Blind spot monitoring warning not appearing. Auto-dimming mirror not responding to light changes. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Faulty impact or occupancy sensor. Sensor out of calibration. Fuel level sending unit failure. Corroded sensor connections. Identifying the root cause is the first step toward finding the right solution.

To resolve this, follow these recommended steps: Connect an OBD-II scanner and read all stored body control module trouble codes. Inspect the affected sensor and its wiring connector for damage or corrosion. Test the sensor resistance or voltage output with a multimeter. Check for physical obstructions, contamination, or misalignment of the sensor. Verify sensor calibration using scan tool where applicable. If these steps do not resolve the issue, consider consulting additional resources or a qualified professional.

This article is part of our Body (B) collection on OBD Codes. We provide comprehensive, up-to-date information to help you find solutions quickly.

Quick Answer

Why does my door ajar light stay on?

A stuck or misaligned door ajar switch is the most common cause. The switch is located in the door latch mechanism and can be cleaned or replaced for $20-$100.

Overview

The B0181 diagnostic trouble code indicates that the body control module has identified a parking sensor circuit malfunction - rear issue. This code means a body sensor or its circuit is not providing expected readings. Accurate sensor data is important for proper operation of safety and convenience systems throughout the vehicle.

Symptoms

  • Window pinch protection not functioning
  • Parking sensors not detecting obstacles
  • Blind spot monitoring warning not appearing
  • Auto-dimming mirror not responding to light changes

Common Causes

  • Faulty impact or occupancy sensor
  • Sensor out of calibration
  • Fuel level sending unit failure
  • Corroded sensor connections

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored body control module trouble codes
  2. 2Inspect the affected sensor and its wiring connector for damage or corrosion
  3. 3Test the sensor resistance or voltage output with a multimeter
  4. 4Check for physical obstructions, contamination, or misalignment of the sensor
  5. 5Verify sensor calibration using scan tool where applicable

Estimated Repair Cost

$50$400

Cost varies by vehicle, location, and repair shop. Includes parts and labor.

Commonly Affected Vehicles

Hyundai TucsonFord EscapeHonda CR-VMazda3

Related Codes

More Sensor Codes

Frequently Asked Questions

A stuck or misaligned door ajar switch is the most common cause. The switch is located in the door latch mechanism and can be cleaned or replaced for $20-$100.