U0171 - Lost Communication With Restraints System Sensor 'B'

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3   
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U0171 Possible Causes

  • Faulty Restraints System Sensor 'B'
  • Restraints System Sensor 'B' harness is open or shorted
  • Restraints System Sensor 'B' circuit poor electrical connection

First diagnose U0171 code

    Check the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

Cost of diagnosing the U0171 code

    Labor: 1.0

    The cost of diagnosing the U0171 code is 1.0 hour of labor. The auto repair labor rates vary by location, your vehicle's make and model, and even your engine type. Most auto repairs shops charge between $75 and $150 per hour.

U0171 Possible Symptoms

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

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 More Information

Need more information on how to fix the U0171 code?
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U0171 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

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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