B0231 code meaning
Front Marker Lamp Circuit
What B0231 means
B0231 is found neither in any publicly available J2012 list nor in public service documents of a carmaker, so the code cannot be verified. The title points to the front marker or position lamps. FMVSS 108 places side marker lamps close to the leading and trailing ends of the body so that, seen from the side, they reveal how long the vehicle is. HELLA lists front marker lights as white, or amber where the headlamps are amber, and mandatory on vehicles wider than 1600 mm. They normally light in the park position of the light switch. A module that switches them electronically can spot a missing load: Ford's patent US4667187A briefly toggles each lamp for about 300 µs and flags a fault when no current change follows. Expect a dark marker lamp and, where fitted, a bulb warning.
B0231 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.2 to 1 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0231
- One front marker or position lamp stays dark with parking lights on
- Bulb failure warning in the instrument cluster, where the car has one
Common causes of B0231
- Most likelyBulb or LED module of the marker lamp failed
- PossibleCorroded bulb holder or plug in the headlamp area, where spray water reaches it
- Less likelyFeed or ground wire to the front lamp open or shorted
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Marker lampBody wiring harness
What each part of B0231 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). |
| 31 | The exact fault in that area. |
What to do next
- Note B0231 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 B0231
What does B0231 mean?
B0231 means "Front Marker Lamp Circuit". B0231 is found neither in any publicly available J2012 list nor in public service documents of a carmaker, so the code cannot be verified. It is a generic code, so it means the same on every make.
Is it safe to drive with B0231?
B0231 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0231 fail an emissions test?
B0231 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 B0231 to fix?
Difficulty: easy. A typical repair takes 0.2 to 1 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will B0231 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.