B0040critical severityBody
Front Crash Sensor Communication Error
on 2007 Hyundai Tucson 2.0L I4 · AWD
What this code means
Communication loss between the front crash sensor and the airbag control module over the dedicated sensor bus.
Symptoms
- Airbag warning light on
- SRS fault stored
- Frontal protection may be degraded
Common causes
- Damaged sensor bus wiring
- Faulty front crash sensor
- ACM internal fault
- Connector pin damage
Diagnostic steps
- Scan SRS codes for communication faults
- Inspect sensor bus wiring
- Check connector pins
- Test sensor power and ground
- Attempt ACM-to-sensor communication test
Repair notes
Repair sensor bus wiring or replace front crash sensor.
Other Body codes on this vehicle
B0001
Driver Frontal Stage 1 Deployment Control
B0002
Driver Frontal Stage 2 Deployment Control
B0003
Passenger Frontal Stage 1 Deployment Control
B0004
Passenger Frontal Stage 2 Deployment Control
B0005
Driver Knee Airbag Deployment Circuit
B0006
Passenger Knee Airbag Deployment Circuit
B0007
Rear Left Side Airbag Deployment Circuit
B0008
Rear Right Side Airbag Deployment Circuit
B0010
Driver Side Airbag Deployment
B0011
Driver Side Airbag Deployment Circuit Open