What it means
The reporting module has lost communication with Restraints System Sensor D. It sets this code when expected sensor messages are not received for a specified time.
How it works
Restraints System Sensor D communicates crash or restraint-related information to the vehicle’s restraint system. U0173 sets when the reporting module stops receiving the expected messages from Sensor D for the required time.
Common causes
Most likely first.
- Sensor D power or ground fault
- Damaged or corroded sensor wiring or connectors
- CAN bus fault
- Restraints sensor D failure
- Low battery voltage
Symptoms
- Airbag warning light
- Restraint system warning message
- Airbags or pretensioners may be unavailable
How to diagnose it
- Scan restraint and related modules for companion communication codes, and save any event or freeze-frame information.
- Check the battery and charging system for low voltage that could have interrupted communication with Sensor D.
- Following the manufacturer's restraint safety procedure, inspect Sensor D’s connector and harness for corrosion, damage, or a loose fit.
- Verify Sensor D’s power and ground against the manufacturer's specification.
- If the supplies are sound, test the communication wiring and network, then evaluate Sensor D for an internal fault.
Common fixes
- Correct a low-voltage condition or poor battery connection.
- Reconnect Sensor D or repair its damaged or corroded wiring.
- Repair a failed power or ground feed to Sensor D.
- Repair the restraint network or replace Sensor D if testing points to that component.
Can I keep driving?
An active restraint communication fault can leave airbags or pretensioners unavailable. Keep driving to a minimum and arrange prompt diagnosis; do not handle restraint-system wiring without the specified safety precautions.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.