What does it mean?
U2018 is a Network (CAN bus, module communications) fault code. It indicates: Passenger-side Side Air Bag Sensor System Communication Error .
Symptoms
- Airbag warning lamp on from key-on and never going out
- Passenger-side airbag and curtain will not deploy in an impact
- Restraint system warning message on the display
- Passenger occupant detection warnings may appear at the same time
- Fault sets again as soon as the code is cleared
- Inspection failure because of the lit airbag lamp
Likely causes
- Passenger-side impact sensor connector not fully latched, corroded or full of moisture
- Damaged wiring in the passenger door or sill, often after trim, carpet or audio work
- Failed passenger-side impact sensor
- Water from a blocked drain or a torn door membrane reaching the sensor and its connector
- Open or shorted sensor circuit back to the restraint control module
- Restraint control module internal fault or poor power and ground
- Unrepaired damage from a previous impact on the passenger side
How to fix it
- Read the restraint module and note whether the code is current and whether a deployment is recorded
- Remove the passenger sill trim and inspect the sensor, bracket and connector
- Reseat the connector and check the terminals for corrosion, spreading and push-back
- Measure the sensor circuit for continuity and short to ground at the module connector
- Dry the footwell and repair any leak before repairing the wiring
- Retorque the sensor to the body at the specified value
- Fit a new impact sensor if the circuit is proven good; the restraint module comes last