◆OBD Codes

C0172

Anti-Roll Bar Position Sensor Circuit - Front

Moderatesensor

Overview

The C0172 diagnostic trouble code means the chassis control module has identified a anti-roll bar position sensor circuit - front problem. This code indicates that a chassis sensor or its circuit is not providing expected readings to the ABS/stability control system. Accurate sensor data is essential for the proper operation of anti-lock brakes, traction control, and electronic stability control, and a fault in this circuit can cause these safety systems to be disabled.

Symptoms

  • ABS warning light illuminated on dashboard
  • Brake pedal position reading inaccurate
  • Traction control warning light on
  • Cruise control will not engage

Common Causes

  • Tire pressure monitor sensor battery depleted
  • Excessive air gap between sensor and tone ring
  • Metallic debris on wheel speed sensor tip
  • Damaged wheel bearing causing sensor misalignment

Diagnosis Steps

  1. 1Connect an OBD-II scanner and read all stored chassis trouble codes and freeze frame data
  2. 2Monitor wheel speed sensor signals using scan tool live data while driving
  3. 3Inspect the affected sensor and its wiring connector for damage or corrosion
  4. 4Check the sensor air gap and tone ring for damage, debris, or excessive wear
  5. 5Test the sensor resistance and voltage output with a multimeter; compare to specifications

Estimated Repair Cost

$100 — $500

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

Commonly Affected Vehicles

Ford FocusHyundai ElantraChevrolet CruzeHonda Civic

Related Codes

C0010C0015C0155

More Sensor Codes

P0070Ambient Air Temperature Sensor Circuit
Low
P0071Ambient Air Temperature Sensor Range/Performance
Low
P0072Ambient Air Temperature Sensor Circuit Low
Low
P0073Ambient Air Temperature Sensor Circuit High
Low
P0074Ambient Air Temperature Sensor Circuit Intermittent
Low
P0095Intake Air Temperature Sensor 2 Circuit
Low

Frequently Asked Questions

The most common causes are a faulty sensor, damaged tone ring, excessive air gap, metallic debris on the sensor tip, corroded wiring, or a worn wheel bearing that allows the sensor to lose alignment with the tone ring.