B0123 code meaning
Pedestrian Alert Speaker B
What B0123 means
B0123 is the same check for pedestrian alert speaker B, which implies a second sounder. Ford's special service message 48451 for 2020 hybrids and plug-ins describes speakers at the front and the rear that sound in forward and reverse between 0 and 30 km/h. In the EU, Regulation 540/2014 made an acoustic vehicle alerting system compulsory on all new hybrid and electric vehicles from July 2021, sounding from start-up to about 20 km/h and when reversing. Stellantis records internal faults of its quiet vehicle pedestrian module as B2779-04, a maker-specific code rather than this one. No manufacturer links B0123 to a particular speaker in public; with B silent, one direction loses its warning and the legal sound requirement is no longer met.
B0123 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0123
- Artificial sound missing at the front or rear, e.g. only audible when moving off forwards
- Possible warning message about the pedestrian alert system
- Legally required warning sound incomplete; have it repaired soon
Common causes of B0123
- Most likelySpeaker B defective, for example from moisture in the rear bumper or wheel arch area
- PossibleLoose or corroded connector at speaker B or a rattling internal connector at the module
- Less likelyFault in the sound generator module or its software
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Pedestrian alert speaker bSpeaker wiringPedestrian alert control module
What each part of B0123 means
| B | Body system: airbags, seat belts, power seats, lights and climate control. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 23 | The exact fault in that area. |
What to do next
- Note B0123 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 B0123
What does B0123 mean?
B0123 means "Pedestrian Alert Speaker B". B0123 is the same check for pedestrian alert speaker B, which implies a second sounder. It is a generic code, so it means the same on every make.
Is it safe to drive with B0123?
B0123 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0123 fail an emissions test?
B0123 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 B0123 to fix?
Difficulty: medium. A typical repair takes 0.5 to 2 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will B0123 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.