What it means
The reporting module has lost communication with Restraints System Sensor A. It sets this code when expected sensor messages are not received for a specified time.
How it works
Restraints System Sensor A provides crash or restraint-related information to the vehicle’s restraint system over a communication network. U0170 sets when the reporting module stops receiving the expected messages from Sensor A for the required time.
Common causes
Most likely first.
- Sensor A power or ground fault
- Damaged or corroded sensor wiring or connectors
- CAN bus fault
- Restraints sensor A failure
- Low battery voltage
Symptoms
- Airbag warning light
- Restraint system warning message
- Airbags or pretensioners may be unavailable
How to diagnose it
- Scan the restraint system and other modules for related codes, and record freeze-frame or event data before clearing anything.
- Check the battery and charging condition, since low system voltage can interrupt restraint sensor communication.
- With the restraint system handled according to the manufacturer's safety procedure, inspect Sensor A’s connector and wiring for damage, corrosion, or a loose connection.
- Check Sensor A’s power and ground against the manufacturer's specification.
- If its supplies are correct, test the relevant communication wiring and network, then assess Sensor A for failure.
Common fixes
- Restore battery condition or repair a poor battery connection if low voltage is present.
- Reconnect or repair damaged wiring at Sensor A.
- Repair a failed power or ground circuit to Sensor A.
- Repair the restraint network wiring or replace Sensor A if testing confirms it is faulty.
Can I keep driving?
Treat the airbag warning as a sign that some restraint functions may be unavailable, including airbags or pretensioners. Drive only if necessary and have the restraint fault diagnosed promptly; do not probe or repair restraint wiring without the required 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.