OBD Codes

B0029

Left Front Impact Sensor Signal Incorrect

Criticalsensor

About B0029

The B0029 diagnostic trouble code indicates that the body control module has identified a left front impact sensor signal incorrect 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: Passenger airbag off indicator lit unexpectedly. Window pinch protection not functioning. SRS malfunction indicator illuminated. Convertible top position incorrectly detected. Understanding these fundamentals will help you diagnose and resolve this issue more effectively.

The most common reasons this occurs include: Physical obstruction blocking sensor. Temperature sensor failure. Damaged sensor wiring or connector. Failed rain or ambient light sensor. 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 B0029 diagnostic trouble code indicates that the body control module has identified a left front impact sensor signal incorrect 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

  • Passenger airbag off indicator lit unexpectedly
  • Window pinch protection not functioning
  • SRS malfunction indicator illuminated
  • Convertible top position incorrectly detected

Common Causes

  • Physical obstruction blocking sensor
  • Temperature sensor failure
  • Damaged sensor wiring or connector
  • Failed rain or ambient light sensor

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 TucsonHonda CR-VToyota CorollaKia Sportage

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.