B0237 code meaning
Backup Lamp Circuit
What B0237 means
Neither the publicly available J2012 lists nor any public service literature mention B0237, so it remains unconfirmed. In the words of FMVSS 108, backup lamps light the road behind the car and warn pedestrians and drivers that it is reversing or about to. HELLA notes that the circuit may only be live with the ignition on and reverse engaged. Manual gearboxes close a plunger switch in reverse; on automatics the range sensor or the transmission controller supplies the signal. In patent US5065135A, held by Automotive Products, logic that decodes the selector position energises a relay feeding the lamp for as long as reverse is reported. A fault leaves the lamps dark in reverse, or lit outside reverse when the line is shorted to supply.
B0237 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyEasy, DIY possible
- Typical labor0.2 to 1.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of B0237
- Reversing lamps stay dark with reverse gear engaged
- Reversing lamps lit while driving forward
Common causes of B0237
- Most likelyReverse light switch on the gearbox worn or its plug corroded by road spray
- PossibleReversing lamp bulb burnt out or LED unit failed
- Less likelyMissing reverse signal from the range sensor or transmission module on automatics
- Less likelyBroken wire in the tailgate harness feeding the lamp
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Backup lampReverse switchBody wiring harness
What each part of B0237 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). |
| 37 | The exact fault in that area. |
What to do next
- Note B0237 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 B0237
What does B0237 mean?
B0237 means "Backup Lamp Circuit". Neither the publicly available J2012 lists nor any public service literature mention B0237, so it remains unconfirmed. It is a generic code, so it means the same on every make.
Is it safe to drive with B0237?
B0237 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will B0237 fail an emissions test?
B0237 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 B0237 to fix?
Difficulty: easy. A typical repair takes 0.2 to 1.5 hours of work. A careful DIY repair is possible with basic tools and a scanner.
Will B0237 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.