U0170
Lost Communication With Restraints System Sensor A
Communication network (airbag/SRS)
Generic OBD-II
Medium
What it means
U0170 means the airbag (SRS) system has lost communication with restraints system sensor A. The vehicle still drives and stops normally, but the airbag warning light will be on and airbags or seatbelt pretensioners may not deploy in a crash. It's usually a wiring, connector, or power/ground fault at the sensor — treat it as a safety priority.
Medium
Can I keep driving? The car drives and stops normally, but the airbag/SRS light will be on and airbags or pretensioners may not deploy in a crash — treat it as a safety priority.
Common symptoms
What you'll notice
- Airbag/SRS warning light on
- Restraints system sensor A not responding to a scan tool
- SRS stored fault indicating a missing sensor
- Airbag system may be disabled while the fault is present
Common causes
Most likely first
- Loss of power or ground to restraints system sensor ALikely
- Corroded, damaged, or loose sensor connector or wiringCommon
- Wiring fault between the sensor and the restraints control moduleCommon
- Water intrusion at the sensor or connectorLess often
- Failed restraints system sensor ALess often
How to diagnose & fix
Work through it in order
- Scan the SRS module and confirm sensor A is unreachable (use care — SRS diagnosis involves live airbag circuits).
- Check battery voltage and the sensor's power and ground feeds.
- Inspect the sensor connector and wiring for corrosion, damage, backed-out pins, or water intrusion.
- Test the wiring between the sensor and the restraints control module for opens or shorts.
- If wiring is good, replace the failed sensor, then clear and re-test. Consider a shop for airbag work.
FAQ
Quick answers
Is it safe to drive with U0170?+
The car drives fine, but your airbags may not work, so fix it promptly and drive carefully in the meantime.
Can I just clear U0170?+
You can, but it returns unless the sensor wiring or the sensor itself is repaired, and the airbag system stays compromised until then.
Related codes
Often seen with U0170
Read & clear U0170 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX