P05BB code meaning
Restraints Deployed
What P05BB means
After a crash the restraint control module tells the engine module that airbags or belt tensioners have fired; the engine module then cuts the fuel pump (Ford: until the ignition is cycled) and possibly the engine. Depending on the maker the message travels over CAN and/or a dedicated wire with a defined level or voltage drop. P05BB is an event code: the engine module received a valid deployment message. The fuel pump is cut, the engine may stop, doors are unlocked by other modules, and Ford's engine module freezes recorded data. After a crash the restraint module must be replaced; a used module with a stored crash can also cause it. No manufacturer document available to us uses this code; it is a safety function, not an emission-relevant monitor, so usually without warning lamp.
P05BB at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor2 to 8 hours
- Clears after repairWhen cleared with a scanner
Symptoms of P05BB
- Engine stops or will not start (fuel cut-off)
- Airbag warning light
- Doors unlocked, fuel cut-off message
Common causes of P05BB
- Most likelyReal accident with airbag or belt tensioner deployment
- Less likelyDeployment after a hard underbody hit (e.g. off-road)
- Less likelyFalse message from wiring or module fault
- Less likelyUsed restraint module with stored crash fitted
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Restraint control moduleCrash signal wiringEngine control module
What each part of P05BB means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 5 | Area: vehicle speed, idle control and auxiliary inputs. |
| BB | The exact fault in that area. |
What to do next
- Note P05BB and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P05BB
What does P05BB mean?
P05BB means "Restraints Deployed". After a crash the restraint control module tells the engine module that airbags or belt tensioners have fired; the engine module then cuts the fuel pump (Ford: until the ignition is cycled) and possibly the engine. It is a generic code, so it means the same on every make.
Is it safe to drive with P05BB?
Drive gently and only to a workshop. With P05BB the car can go into limp mode (reduced power) to protect itself.
Will P05BB fail an emissions test?
P05BB is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is P05BB to fix?
Difficulty: hard. A typical repair takes 2 to 8 hours of work. This is a job for a workshop.
Will P05BB clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.