What it means
The control module detected a deployed restraint system. The code alone does not specify which restraint deployed or how the vehicle handles the condition.
At a glance
- Usually lights the check-engine light
How it works
The restraint control module monitors deployment status for the vehicle’s restraint system, which can include airbags and seat-belt pretensioners. P05BB is set when the module records that a restraint has deployed; the code does not identify which component deployed or whether the vehicle can still operate normally.
Common causes
Most likely first.
- Restraint deployment recorded after a crash
- Fault in the restraint deployment status circuit or module
- Incorrect module configuration
Symptoms
- Airbag or restraint warning light
- A restraint system fault message may appear
- Deployed restraint components may be evident
How to diagnose it
- Use a compatible scan tool to read restraint-module codes and freeze-frame or event data, since related codes may identify the affected restraint or a deployment event.
- With the vehicle safely parked, check for visible signs of crash damage or deployed airbags and pretensioners before attempting to clear codes.
- Inspect accessible restraint-module connectors and wiring for impact damage, loose connections, corrosion, or disturbed wiring.
- Compare the module’s deployment status and configuration with the vehicle’s service information to determine whether deployment is recorded correctly.
- If no deployment is evident, test the deployment-status circuit and module configuration using the manufacturer’s diagnostic procedure.
Common fixes
- Repair damaged restraint-system wiring or connectors using the manufacturer’s approved procedure.
- Correct an incorrect restraint-module configuration or coding.
- Replace the restraint module if its deployment-status circuit or internal fault is confirmed.
- Replace deployed airbags, pretensioners, and other affected restraint components after a crash.
Can I keep driving?
Treat the restraint system as unavailable until it has been inspected; an airbag or pretensioner may not protect occupants in another crash. If a restraint has deployed or the vehicle was in a collision, do not drive it until it is safe to operate and the restraint system has been assessed.
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.