Mazda B11C4
23 (BCM - liftgate lock switch circuit malfunction) may be stored. This may be caused during a high pressure car wash and/or condensation. Water may enter through the rear center b
Quick answer
For a 2022 Mazda MX-30 in the US, DTC B11C4:23 may be associated with a liftgate interior-trim door-lock switch that does not operate. Mazda communications state that water intrusion during high-pressure washing and/or condensation can enter through the rear center brand-emblem base, drip onto the switch connector, and cause corrosion.
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 B11C4 mean?
For a 2022 Mazda MX-30 in the US, DTC B11C4:23 may be associated with a liftgate interior-trim door-lock switch that does not operate. Mazda communications state that water intrusion during high-pressure washing and/or condensation can enter through the rear center brand-emblem base, drip onto the switch connector, and cause corrosion.
2. Technical explanation
Mazda identifies B11C4:23 as “BCM - liftgate lock switch circuit malfunction.” Verified manufacturer communications state that the rear center brand-emblem base component can allow water to reach the liftgate lock-switch connector. Corrosion at that connector is identified as the concern addressed by a modified rear switch with a waterproof connector.
3. What system is affected?
Body Control Module (BCM), liftgate interior-trim door-lock switch circuit, and its connector.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
- The vehicle door-locking system may not work when the door-lock switch on the liftgate interior trim is pressed.
- DTC B11C4:23 may be stored.
- A rusted connector may cause battery drain.
6. Possible causes
- Water exposure during a high-pressure car wash.
- Condensation.
- Water entering through the rear center brand-emblem base component and dripping onto the liftgate lock-switch connector.
- Corrosion of the switch connector.
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
- If the liftgate interior door-lock switch does not operate or B11C4:23 is stored, arrange inspection by a Mazda dealer or qualified service facility.
- Provide the technician with Mazda manufacturer communications 09-013-25 and 09-028-23.
- Avoid assuming that a battery drain is unrelated, because Mazda states that a rusted connector may cause battery drain.
10. Step-by-step troubleshooting
- Confirm whether the door-locking system fails specifically when the liftgate interior-trim door-lock switch is pressed.
- Check for stored DTC B11C4:23 using appropriate diagnostic equipment.
- Have the liftgate lock-switch connector and the rear center brand-emblem base area inspected for the water-intrusion and corrosion concern described by Mazda.
11. When to contact service
Contact a Mazda dealer or qualified service facility for diagnosis if the liftgate interior door-lock switch does not operate, B11C4:23 is stored, or battery drain is suspected.
12. What the service center may check
- Verify DTC B11C4:23.
- Inspect the liftgate lock-switch connector for corrosion.
- Inspect the rear center brand-emblem base component for the water-entry path described in Mazda communications.
- Assess whether the connector condition is contributing to battery drain.
13. Possible repair or resolution
- Mazda states that the rear switch was modified with a waterproof connector to eliminate the concern. Exact repair applicability and procedure must be confirmed by the servicing facility.
14. Affected vehicles
- Mazda MX-30 · 2022 · US
15. Related TSBs / service bulletins
- Mazda manufacturer communication 09-013-25, published March 13, 2025; NHTSA document MC-11016214-0001: https://static.nhtsa.gov/odi/tsbs/2025/MC-11016214-0001.pdf
- Mazda manufacturer communication 09-028-23, published July 7, 2023; NHTSA document MC-10240399-0001: https://static.nhtsa.gov/odi/tsbs/2023/MC-10240399-0001.pdf
16. Recall information
- Not yet established by verified evidence.
17. Official manufacturer information
Verified applicability: 2022 Mazda MX-30, US. The supplied official NHTSA-hosted Mazda communications describe B11C4:23 and the liftgate lock-switch water-intrusion concern.
19. Frequently asked questions
What does Mazda DTC B11C4:23 mean?
Mazda identifies B11C4:23 as “BCM - liftgate lock switch circuit malfunction.”
What may happen with B11C4:23?
The door-locking system may not work when the liftgate interior-trim door-lock switch is pressed. Mazda also states that a rusted connector may cause battery drain.
What can cause this concern?
Mazda states it may occur during a high-pressure car wash and/or from condensation, when water enters through the rear center brand-emblem base component, drips onto the switch connector, and causes corrosion.
Does Mazda identify a corrective design change?
Yes. Mazda states that the rear switch was modified with a waterproof connector to eliminate the concern.