P05BB
Restraints Deployed.
- Generic
- Powertrain
- Generic code
- High severity
How this code is built
- P
- SystemPowertrain
- 0
- Defined bySAE, the same on every car
- 5
- AreaVehicle speed, idle control and auxiliary inputs
- BB
- FaultThe specific fault in that area
What it means
P05BB means the powertrain control module has received a signal that the vehicle's restraints, such as airbags or seatbelt pretensioners, have been deployed. This is normally reported by the restraint control module over the vehicle network after a collision. The engine control unit may respond by limiting or cutting the engine or fuel supply as a safety measure. The exact response depends on the make and model.
Symptoms
- Airbag or SRS warning light on, and possibly the engine warning light too
- Engine cranks but will not start, or stalls after a collision
- Reduced power or limp mode on some models
- Visible airbag deployment or signs of an earlier impact
- Fuel pump cut-off has tripped on some models
- Other crash-related fault codes stored in the restraint system
Possible causes
- Genuine deployment of airbags or pretensioners in a collisionlikely
- Crash or deployment status not reset in the restraint control module after a repairlikely
- Damage to the crash sensors, restraint control module or its wiring from an impactpossible
- Network wiring or connector fault between the restraint module and the engine control unit giving a false deployment messagepossible
- Incorrect or unmatched restraint control module fitted during repairpossible
- Water ingress or corrosion in the restraint module or its connectorsrare
How to diagnose
- Ask about the vehicle's history and look for signs of impact or previous airbag deployment
- Read all stored codes and freeze frame data from the engine and restraint systems, and note which control unit set the code
- Check the restraint system for crash data and deployment status using live data
- Inspect the airbags, seatbelt pretensioners, crash sensors and their wiring and connectors for damage, corrosion or water ingress
- Check the network wiring and connectors between the restraint module and the engine control unit for faults
- Confirm the restraint control module is the correct type for the vehicle and is coded properly
- Follow the manufacturer's procedure for the vehicle, as the response and the reset method vary by model
- After repair, recheck codes and confirm the status does not return
How to fix
- Repair the collision damage and replace all deployed or damaged restraint components, including airbags, pretensioners and sensors, as the manufacturer specifies
- Replace or repair the restraint control module if it is damaged or has stored crash data that cannot be cleared
- Once the restraint system is fully repaired and verified, reset the crash status using the manufacturer's procedure
- Repair damaged wiring, connectors or network faults between the restraint module and the engine control unit
- Fit the correct module for the vehicle and code it properly if the wrong one was fitted
Can I keep driving?
High severity
Do not drive the car until the restraint system has been inspected and repaired, as the airbags may not protect you in another collision. If the car has been in a crash, have it checked and recovered if needed.
Guide written by AI from the code's definition. Confirm with a diagnosis before replacing parts.