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U0171 Code - Lost Communication With Restraints System Sensor 'B'

- Code Popularity: 5,018 Views
- Repair Importance Level: 3/3
- Repair Difficulty Level: 3/3
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What are the Possible Causes of the DTC U0171?

NOTE: The causes shown may not be a complete list of all potential problems, and it is possible that there may be other causes.
  • Faulty Restraints System Sensor 'B'
  • Restraints System Sensor 'B' harness is open or shorted
  • Restraints System Sensor 'B' circuit poor electrical connection
⚠ Does your Car have Safety Recalls? → Check here

How to Fix the DTC U0171?

Review the 'Possible Causes' mentioned above and visually examine the corresponding wiring harness and connectors. Ensure to check for any damaged components and inspect the connector pins for signs of being broken, bent, pushed out, or corroded.

Search for U0171 Questions and Answers: Search here →

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0171 code, it typically requires 1.0 hour of labor. The specific diagnosis time and labor rates at auto repair shops can differ based on factors such as the location, make and model of the vehicle, and even the engine type. It is common for most auto repair shops to charge between $75 and $150 per hour.

What are Code Possible Symptoms?

  • Air Bag Warning Light ON
  • Engine Light ON (or Service Engine Soon Warning Light)

Code U0171 Description

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages are needed to be exchanged on the serial data circuits. CAN bus uses two dedicated wires for communication. The wires are called CAN high and CAN low. When the CAN bus is in idle mode, both lines carry 2.5V. When data bits are being transmitted, the CAN high line goes to 3.75V, and the CAN low drops to 1.25V, thereby generating a 2.5V differential between the lines. Since communication relies on a voltage differential between the two bus lines, the CAN bus is NOT sensitive to inductive spikes, electrical fields, or other noise. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Restraints System Sensor 'B' has not been received.

OBDII Code U0171 - Lost Communication With Restraints System Sensor 'B' - AutoCodes.com
U0171 Code - Lost Communication With Restraints System Sensor 'B'

Need More Information on the Code?

Need more information on how to fix the U0171 code? Get Access to Factory Service Manuals

Information for Specific Makes

  • U0171 Chrysler Lost Communication With Up-Front Right Satellite Acceleration Sensor
  • U0171 Dodge Lost Communication With Up-Front Right Satellite Acceleration Sensor
  • U0171 Fiat Lost Communication With Up-Front Right Satellite Acceleration Sensor
  • U0171 Jeep Lost Communication With Up-Front Right Satellite Acceleration Sensor
  • U0171 RAM Lost Communication With Up-Front Right Satellite Acceleration Sensor

Need Help with the Code?

Get the U0171 code diagnosed by a professional: Find a repair shop in your area

Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service

  • Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
  • Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
  • Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
  • Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.
Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

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