What it means
A control module is not receiving expected messages from Restraints System Sensor K. 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 K sends vehicle-specific information to the restraint system over the vehicle network. U017A means a control module has not received the expected Sensor K messages for the required time; a missing power supply, damaged wiring, gateway routing fault, or CAN termination problem can cause this.
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 all modules and review freeze-frame data for U017A, noting any related network codes or low-voltage events.
- Use vehicle service information to locate Sensor K and check its connector and harness for damage, corrosion, loose pins, or disconnection.
- Verify Sensor K power and ground against the manufacturer's specification.
- Check whether the gateway reports routing faults and whether other modules on the same network are also offline.
- Test CAN wiring and termination according to the manufacturer's procedure, rather than relying on a universal resistance value.
- If power, wiring, gateway, and network checks are satisfactory, test Sensor K using the manufacturer's restraint-system diagnostic procedure.
Common fixes
- Restore Sensor K power or ground by repairing the affected connection or circuit.
- Repair or secure a damaged Sensor K connector or harness.
- Repair a confirmed gateway or CAN network fault.
- Replace Sensor K if testing confirms the sensor is faulty.
Can I keep driving?
The restraint function that depends on Sensor K may be impaired, so arrange diagnosis promptly and drive cautiously until the system is checked. Do not disconnect or test restraint-system components without following 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.