C0023 code meaning
Stop Lamp Control
What C0023 means
Covers the stop lamp (brake light) control circuit as driven or monitored by the brake or stability control module. Modern ABS/ESC systems can command the stop lamps during autonomous braking events such as traction control, stability control and automatic emergency braking, independent of the driver pressing the pedal, and they monitor the circuit for opens, shorts and lamp-output disagreement. The code is stored when the commanded stop lamp state does not match the measured output or the circuit is faulty. Effects range from stop lamps that stay on or off to disabled driver-assist functions that rely on brake-light actuation. Mazda stores C0023:14 as a brake light circuit malfunction and names a retrofitted brake light flasher as one trigger (service alert SA-041-26). NHTSA's brake study lists brake lights on/off as a CHB output.
C0023 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium, DIY possible
- Typical labor0.5 to 2 hours
- Clears after repairWhen cleared with a scanner
Symptoms of C0023
- Stop lamps stay on or do not light
- Stability or driver-assist functions disabled
- ABS or stability warning lamp on
Common causes of C0023
- Most likelyOpen or shorted stop lamp wiring
- PossibleFailed lamp or output driver
- Less likelyFaulty brake switch signal
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Stop lamp control circuit
What each part of C0023 means
| C | Chassis system: brakes, ABS, steering and suspension. |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 23 | The exact fault in that area. |
What to do next
- Note C0023 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 C0023
What does C0023 mean?
C0023 means "Stop Lamp Control". Covers the stop lamp (brake light) control circuit as driven or monitored by the brake or stability control module. It is a generic code, so it means the same on every make.
Is it safe to drive with C0023?
Drive gently and only to a workshop. With C0023 the car can go into limp mode (reduced power) to protect itself.
Will C0023 fail an emissions test?
C0023 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 C0023 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 C0023 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.