OBD Guide

U0172

Lost Communication With Restraints System Sensor C

Severity
🔴 High
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$56–167 (est.)

Symptoms

  • The airbag light on the dashboard is on
  • The passive safety system can be disabled
  • Lack of response from shock sensors during diagnostics
  • Errors in other security system modules

Causes

  • Open or short circuit in the sensor circuit
  • Safety sensor fault C
  • Wiring harness damage
  • Corrosion or poor contact in connectors
  • Problems with the security ECU

How to Fix

  1. Check the continuity of the sensor circuit using a multimeter
  2. Inspect connectors and contacts for corrosion or damage
  3. Check the power supply and ground of the sensor
  4. If necessary, replace the faulty sensor
  5. Repair only from an authorized dealer

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