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Hyundai B1621

ECU Defect/Error

DriveNot yet established by verified evidence.
ChargeNot yet established by verified evidence. The supplied evidence concerns wireless phone charging, not vehicle traction-battery charging.
ServiceService is appropriate if B1621 is stored. The verified Hyundai communication directs replacement of the wireless charger pad when this DTC is found.
Confidence95%

Quick answer

For the applicable 2018–2019 Hyundai Kona and Sonata in the US, DTC B1621 means “ECU Defect/Error.” Hyundai’s referenced service communication directs technicians to replace the wireless charger pad when this code is found.

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 B1621 mean?

For the applicable 2018–2019 Hyundai Kona and Sonata in the US, DTC B1621 means “ECU Defect/Error.” Hyundai’s referenced service communication directs technicians to replace the wireless charger pad when this code is found.

2. Technical explanation

The verified NHTSA-hosted Hyundai communication 19-BE-003H identifies B1621 as an ECU Defect/Error code in the wireless phone-charging diagnostic procedure. Its stated action is: use the GDS to scan for DTCs; if B1621 is found, replace the wireless charger pad.

3. What system is affected?

Wireless phone charging pad/system.

4. How serious is this code?

Not yet established by verified evidence.

5. Symptoms you may notice

  • Wireless phone charging may be stopped or not operate; the supplied communication addresses this condition, but it does not explicitly state that B1621 alone confirms a particular user-visible symptom.

6. Possible causes

  • The verified communication identifies B1621 as “ECU Defect/Error” and specifies replacement of the wireless charger pad when the code is found.
  • A more specific underlying component-level cause is not yet established by verified evidence.

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. The supplied evidence concerns wireless phone charging, not vehicle traction-battery charging.

9. What you can safely do

  • Confirm the key fob is inside the vehicle when checking wireless phone-charging operation.
  • Check the wireless charging-pad harness connection; if it is not fully connected, reconnect it and recheck charging status.
  • Allow the charging mat and phone to cool if their temperature is above approximately 40 °C; the communication states the wireless charging system shuts down above this temperature.
  • Have a Hyundai service facility scan the vehicle with GDS and follow the applicable diagnostic procedure.

10. Step-by-step troubleshooting

  1. Verify that the key fob is inside the vehicle, because the communication states charging stops while the vehicle is searching for the key fob.
  2. Inspect the wireless charging-pad harness connection and reconnect it if it is not fully connected.
  3. Check whether the charging mat or phone is below approximately 40 °C.
  4. Use GDS to scan for DTCs. If B1621 is present, the communication directs replacement of the wireless charger pad.

11. When to contact service

Service is appropriate if B1621 is stored. The verified Hyundai communication directs replacement of the wireless charger pad when this DTC is found.

12. What the service center may check

  • Scan for DTCs using Hyundai GDS.
  • Confirm key-fob presence inside the vehicle.
  • Check the wireless charging-pad harness connection.
  • Check charging-mat and phone temperature against the approximately 40 °C operating limit.
  • If B1621 is found, replace the wireless charger pad.

13. Possible repair or resolution

  • Replace the wireless charger pad when DTC B1621 is found, as directed by Hyundai communication 19-BE-003H.

14. Affected vehicles

15. Related TSBs / service bulletins

  • Hyundai communication 19-BE-003H, published February 12, 2019; NHTSA Manufacturer Communication PDF 10154676. It includes wireless phone-charger diagnostic guidance and directs replacement of the wireless charger pad if B1621 is found.
  • Verified applicability in the supplied data: 2018–2019 Hyundai Kona, US; 2018–2019 Hyundai Sonata, US.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

NHTSA-hosted Hyundai Manufacturer Communication PDF 10154676, 19-BE-003H: https://static.nhtsa.gov/odi/tsbs/2019/MC-10154676-9999.pdf

19. Frequently asked questions

What does Hyundai code B1621 mean?

It means “ECU Defect/Error,” according to the supplied Hyundai diagnostic record and service communication.

What system does the verified service information address?

The wireless phone-charging pad/system.

What does Hyundai direct a technician to do if B1621 is found?

Scan with GDS and replace the wireless charger pad if B1621 is present.

Does B1621 affect EV battery charging?

Not yet established by verified evidence. The supplied communication concerns wireless phone charging rather than traction-battery charging.

Which vehicles are verified as applicable?

The supplied applicability data identifies US-market 2018–2019 Hyundai Kona and 2018–2019 Hyundai Sonata vehicles.

20. Sources & verification

Verified
Hyundai B1621: ECU Defect/Error | EV Diagnostics