B00D4Restraint System Malfunction Audible Indicator
- Generic OBD-II code · Body
- How the car detects it
- B00D4 concerns the audible restraint warning, the tone that stands in when a fault cannot be shown by the lamp. Ford's 2014 F-150 manual describes it: system readiness is signalled by the warning light, or by a backup tone if the light is out, and a problem announces itself as five beeps in a row, repeated until the fault and the lamp are put right. Audi's 1986 patent explains why such a fallback exists: a blown fuse could kill both the airbag module and its lamp, so the driver would believe the system was fine; it mentions an audible alarm as an alternative signal. No carmaker publishes B00D4. A stored code means the restraint module sees a fault in its chime or speaker path, so a later lamp failure could go wholly unannounced.
- What you may notice
- No warning tone where one would be expected, other warning chimes may also be silent
- Airbag warning lamp on
- Safety note: fallback warning missing; work on cluster and restraint wiring only de-energised (ignition off, battery off, wait time), specialist workshop
- Likely causes
- PossibleOpen or shorted lead to the chime or speaker used for restraint warnings
- PossibleChime module or cluster speaker failed
- RareTone request from the restraint module not received by the sounding unit
- Repair
- Medium · Usually a job for a workshop.Typical cost: €40 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.