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Mazda C0023

14 (Brake light circuit malfunction) stored. This may be caused by an aftermarket brake light flasher. Page 5 of 6 05/24/2023 09:34 AM tlawrenc REPAIR PROCEDURE 1. Verify the custo

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence.
ServiceContact a Mazda dealer or qualified service provider if C0023:14 is stored, particularly if an aftermarket brake light flasher is fitted. The verified Mazda communication directs verification of the concern when an aftermarket device may be involved.
Confidence95%

Quick answer

For Mazda C0023:14, verified evidence identifies a brake light circuit malfunction and states that an aftermarket brake light flasher may cause the code.

This page separates verified manufacturer/regulator evidence from supporting material. Unsupported causes, repairs or safety conclusions are not guessed.

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1. What does C0023 mean?

For Mazda C0023:14, verified evidence identifies a brake light circuit malfunction and states that an aftermarket brake light flasher may cause the code.

2. Technical explanation

Mazda service communications list DTC C0023:14 as “Brake light circuit malfunction.” The communications specifically identify an aftermarket brake light flasher as a possible cause. The supplied evidence does not establish other diagnostic causes, component failures, or a vehicle-specific repair beyond verifying whether an aftermarket device is responsible.

3. What system is affected?

Brake light circuit.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • DTC C0023:14 stored.
  • A brake light circuit malfunction is indicated by the DTC description.

6. Possible causes

  • An aftermarket brake light flasher may cause DTC C0023:14.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Not yet established by verified evidence.

9. What you can safely do

  • Check whether the vehicle has an aftermarket brake light flasher or related aftermarket device installed.
  • Have a Mazda dealer or qualified service provider evaluate the brake light circuit and any aftermarket installation.
  • Do not perform high-voltage system repairs based on this code; the supplied evidence concerns the brake light circuit.

10. Step-by-step troubleshooting

  1. Verify the customer concern.
  2. If an aftermarket brake light flasher is installed, determine whether it is responsible for the stored C0023:14 code. Mazda communications state that this device may cause the code.
  3. The supplied verified evidence does not provide further test steps, wiring checks, or component-level diagnostic specifications.

11. When to contact service

Contact a Mazda dealer or qualified service provider if C0023:14 is stored, particularly if an aftermarket brake light flasher is fitted. The verified Mazda communication directs verification of the concern when an aftermarket device may be involved.

12. What the service center may check

  • Verify the customer concern.
  • Inspect for an aftermarket brake light flasher or other relevant aftermarket device.
  • If the concern is verified to be caused by an aftermarket device, Mazda’s 2023 communication says to photograph the device and include the photo with the repair order.

13. Possible repair or resolution

  • If the concern is verified to be caused by an aftermarket device, the supplied Mazda communication identifies that device as the relevant source of the concern. A specific removal, replacement, or circuit repair procedure is not established by the supplied evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Mazda service communication SA-032-23, NHTSA Manufacturer Communication 10237216, published May 24, 2023: identifies C0023:14 as a brake light circuit malfunction that may be caused by an aftermarket brake light flasher.
  • Mazda service communication SA-032-23a, NHTSA Manufacturer Communication 10244679, published October 11, 2023: repeats the aftermarket brake light flasher example for C0023:14.
  • Mazda service communication SA-057-24, NHTSA Manufacturer Communication 11007019, published August 15, 2024: repeats the aftermarket brake light flasher example for C0023:14.
  • Mazda service communication SA-061-25, NHTSA Manufacturer Communication 11026917, published December 17, 2025: repeats the aftermarket brake light flasher example for C0023:14.
  • Mazda service communication SA-041-26, NHTSA Manufacturer Communication 11034447, published June 19, 2026: lists DTC C0023:14 among examples involving aftermarket devices.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Verified official NHTSA-hosted Mazda manufacturer communications apply the C0023:14 aftermarket brake light flasher information to US-market Mazda CX-70 (2022–2026), CX-90 (2022–2026), and MX-30 (2022–2026), with overlapping year ranges in the supplied applicability data. Vehicle-specific applicability should be confirmed using the VIN and current Mazda service information.

19. Frequently asked questions

What does Mazda code C0023:14 mean?

The verified Mazda communications describe C0023:14 as a brake light circuit malfunction.

Can an aftermarket brake light flasher cause C0023:14?

Yes. Mazda communications state that C0023:14 may be caused by an aftermarket brake light flasher.

Is it safe to drive with C0023:14?

Not yet established by verified evidence.

Does C0023:14 affect EV charging?

Not yet established by verified evidence.

Does the evidence identify a recall for C0023:14?

No recall is established by the supplied verified evidence.

20. Sources & verification

ReferenceVerified
Mazda C0023: 14 (Brake light circuit malfunction) stored. This may be… | EV Diagnostics