Lost Communication With Restraints System Sensor D
What it means
U0173 means the vehicle has lost communication with restraints system sensor "D" — one of the crash/satellite sensors that feed the airbag (SRS) system. When it goes offline, the SRS warning light comes on and the restraint system may not deploy correctly in a crash. The car drives normally, but occupant protection is compromised, so this should be diagnosed promptly. The cause is usually a wiring, connector, power/ground, or bus fault.
Can I keep driving? The car drives normally, but the airbag/SRS warning will be on and the restraint system may not fully protect you in a crash — have it inspected promptly.
Common symptoms
What you'll notice
- Airbag/SRS warning light on
- Restraints fault message
- Airbag deployment for the affected zone may be disabled
- Scan tool can't reach restraints system sensor D
Common causes
Most likely first
- Wiring or connector fault at the sensor (in an impact-zone location)Likely
- Power or ground problem to the sensorCommon
- Failed restraints system sensorCommon
- SRS/CAN bus wiring faultLess often
How to diagnose & fix
Work through it in order
- Scan the restraints system for related codes — SRS work carries deployment risk, so disconnect the battery and wait per the service manual first.
- Inspect the sensor's connector and wiring for damage or corrosion.
- Check the sensor's power and ground.
- Verify bus communication to the sensor.
- Have SRS repairs done by a qualified tech; replace and program the sensor if confirmed faulty.
FAQ
Quick answers
Is it safe to drive with U0173?+
Can I just clear U0173?+
Related codes
Often seen with U0173
Read & clear U0173 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.