OBD Code U0171
Lost Communication With Restraints System Sensor B
| Code | U0171 |
| Description | Lost Communication With Restraints System Sensor B |
| System | Network |
What Does U0171 Mean?
Lost Communication With Restraints System Sensor B. This diagnostic trouble code (DTC) is stored when the vehicle's onboard computer detects an issue with the network.
Code Breakdown
U = Network code
0 = Generic (SAE standard)
How to Fix U0171
Follow these diagnostic steps to identify and resolve the issue. Always start with the simplest checks before moving to more involved repairs.
- Warning: Disconnect battery before working on SRS components.
- Check wiring between the airbag control module and individual airbag sensors.
- Inspect connectors for corrosion, especially in crash sensors located in the bumper or door areas.
- Verify the CAN bus communication lines to the airbag module are intact.
- Check for TSBs regarding airbag module software updates.
- If the airbag module has lost communication, it may need replacement and coding at a dealer.
- Clear codes and verify the SRS light stays off.
Note: These are general diagnostic guidelines. Some vehicles may have model-specific procedures. Always consult your vehicle's service manual for exact specifications and torque values. If you are not comfortable performing these steps, visit a qualified mechanic.
Frequently Asked Questions
Is U0171 serious?
Yes, U0171 is considered a critical-severity code. You should have it diagnosed and repaired as soon as possible. Driving with this code active may cause further damage to your vehicle or pose a safety risk.
Can I clear U0171 myself?
You can clear any OBD-II code with a code scanner or by disconnecting the battery for 15-30 minutes. However, clearing the code without fixing the underlying problem will cause it to return, usually within one or two drive cycles. If the code triggered the check engine light, the light will come back on. Fix the root cause first, then clear the code.
How much does it cost to fix U0171?
Repair costs vary widely depending on the root cause. Some fixes are free (like tightening a gas cap) while others can cost several hundred dollars (like replacing a catalytic converter or oxygen sensor). A proper diagnosis with a professional scan tool, not just reading the code, is the first step to getting an accurate repair estimate. Many auto parts stores offer free code reading, but a thorough diagnosis usually requires a mechanic.