What it means
A control module is not receiving expected messages from Restraints System Sensor N. The code indicates a communication fault; the sensor's specific role depends on the vehicle.
At a glance
- Usually lights the warning light of the system that lost communication
How it works
Restraints System Sensor N communicates vehicle-specific information to the restraint system over the vehicle network. U017D is stored when a control module misses Sensor N messages for the required interval, potentially because of a power or ground fault, damaged wiring, gateway routing issue, or CAN termination fault.
Common causes
Most likely first.
- Sensor unpowered or wiring broken
- Gateway module routing CAN messages incorrectly
- CAN terminating resistor (120 Ω) drifted out of spec
Symptoms
- Airbag or restraint-system warning
- Restraint functions associated with the sensor may be impaired
- Other communication codes
How to diagnose it
- Scan every accessible module and review freeze-frame data to check for other communication codes or low-voltage conditions.
- Locate Sensor N using vehicle service information and inspect its connector and harness for corrosion, damage, loose pins, or disconnection.
- Check power and ground at Sensor N against the manufacturer's specification.
- Review gateway codes and see whether other modules sharing the network have also stopped communicating.
- Test the CAN wiring and termination according to the manufacturer's procedure.
- If the sensor supply and network path are sound, follow the manufacturer's restraint-system tests to assess Sensor N.
Common fixes
- Repair a faulty Sensor N power or ground feed.
- Repair damaged wiring or clean and secure the sensor connector.
- Correct a confirmed gateway or CAN network fault.
- Replace Sensor N if the manufacturer’s tests confirm it is defective.
Can I keep driving?
Airbag or pretensioner functions associated with Sensor N may be unavailable, so have the restraint system checked promptly and drive cautiously. Keep clear of restraint-system connectors unless carrying out the vehicle’s specified safety procedure.
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.