OBD-II code · Powertrain (generic)
P05B8 Restraint Deployment Signal Circuit Open
The signal line that the restraint control module uses to inform the engine ECU about a deployment event has an open circuit. The ECU cannot run its post-crash strategy (fuel cutoff, hazard lights, unlock) automatically on impact.
Is it safe to drive with P05B8?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in signal wire
- Less likelyPin pushed back out of connector body
- Less likelyCracked solder joint inside the module or sensor
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.6–2 h
- Emissions test
- Usually unaffected
- Parts involved
- Restraint Control Module, Restraint Signal Wiring
Related codes
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.