Hyundai C1622
MDPS assy is not to be replaced. C1612, C1646 TCU signal error Check TCU and associated wiring. C1628, C1656 Instrument cluster signal error Check instrument cluster and associated
Quick answer
Hyundai DTC C1622 is identified in the supplied official service-bulletin evidence as a vehicle-speed-signal error. The bulletin directs technicians to check the EMS (Engine ECU) and states that the full C-MDPS assembly is not to be replaced for this 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 C1622 mean?
Hyundai DTC C1622 is identified in the supplied official service-bulletin evidence as a vehicle-speed-signal error. The bulletin directs technicians to check the EMS (Engine ECU) and states that the full C-MDPS assembly is not to be replaced for this code.
2. Technical explanation
The verified Hyundai bulletin evidence describes C1622 as “Vehicle speed signal error.” It associates the diagnostic direction with the EMS (Engine ECU): “Check the EMS (Engine ECU).” The same bulletin states: “Full C-MDPS assy is not to be replaced.” A separate verified bulletin flowchart groups C1622 among connectors/wiring-related DTCs and directs: check R-MDPS connectors and wiring, erase DTC(s) and re-check, then follow the recommended repairs if the DTC remains present.
3. What system is affected?
Verified evidence identifies an MDPS/C-MDPS diagnostic context and a vehicle-speed-signal relationship involving the EMS (Engine ECU). The exact failed component is not yet established by verified evidence.
4. How serious is this code?
Not yet established by verified evidence.
5. Symptoms you may notice
Not yet established by verified evidence.
6. Possible causes
- Vehicle speed signal error, as identified by the verified Hyundai bulletin.
- EMS (Engine ECU) issue or related signal-path concern requiring inspection, as directed by the verified Hyundai bulletin.
- R-MDPS connector or wiring concern, based on the verified flowchart’s grouping of C1622 as connectors/wiring-related.
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
- Arrange diagnosis by a qualified Hyundai service technician.
- Use the applicable diagnostic process: inspect the EMS (Engine ECU) and check relevant R-MDPS connectors and wiring.
- Do not replace the full C-MDPS/MDPS assembly solely because C1622 is stored; the verified bulletin specifically says it is not to be replaced for this code.
10. Step-by-step troubleshooting
- Check the EMS (Engine ECU), as specified for C1622 in Hyundai bulletin 20-ST-001H-1 and 20-ST-001H-2.
- Check R-MDPS connectors and wiring, as specified by Hyundai bulletin 22-ST-001H.
- Erase the DTC(s) and re-check, as specified by Hyundai bulletin 22-ST-001H.
- If the DTC remains present, follow the recommended repair path in the applicable Hyundai bulletin.
11. When to contact service
Service diagnosis is appropriate. The supplied Hyundai bulletins provide a specific diagnostic path for C1622 and expressly advise against replacement of the full C-MDPS/MDPS assembly for this code.
12. What the service center may check
- Retrieve and confirm stored DTCs.
- Inspect the EMS (Engine ECU) in relation to the vehicle-speed-signal error.
- Inspect R-MDPS connectors and wiring.
- Erase DTCs and verify whether C1622 returns.
- Follow the applicable Hyundai repair flowchart if the code remains present.
13. Possible repair or resolution
- Do not replace the full C-MDPS/MDPS assembly for C1622, according to the verified Hyundai bulletin.
- Repair resolution beyond the prescribed inspection, erase-and-recheck process is not yet established by verified evidence.
14. Affected vehicles
- Hyundai Kona · 2016–2021 · US
- Hyundai Kona · 2016–2020 · US
- Hyundai Sonata · 2016–2017 · US
- Hyundai Sonata · 2016–2021 · US
- Hyundai Sonata · 2016–2020 · US
15. Related TSBs / service bulletins
- Hyundai TSB 20-ST-001H-1, published August 10, 2020 (NHTSA manufacturer communication MC-10179244): identifies C1622 as a vehicle-speed-signal error; directs checking the EMS (Engine ECU); states the full C-MDPS assembly is not to be replaced.
- Hyundai TSB 20-ST-001H-2, published September 9, 2020 (NHTSA manufacturer communication MC-10180981): repeats the C1622 vehicle-speed-signal diagnostic direction and instruction not to replace the full C-MDPS assembly.
- Hyundai TSB 22-ST-001H, published January 6, 2022 (NHTSA manufacturer communication MC-10207815): lists C1622 as connectors/wiring-related and directs inspection of R-MDPS connectors and wiring, DTC clearing, and re-checking.
16. Recall information
No recall relationship is established by verified evidence.
17. Official manufacturer information
Verified official NHTSA-hosted Hyundai manufacturer communications support this page. The supplied applicability records list US-market Hyundai Kona model years 2016–2021 and Hyundai Sonata model years 2016–2021, with overlapping year ranges in the source data. Exact applicability to a particular vehicle should be confirmed by VIN and the applicable Hyundai bulletin.
19. Frequently asked questions
What does Hyundai C1622 mean?
Verified Hyundai bulletin evidence identifies C1622 as a vehicle-speed-signal error.
Should the MDPS assembly be replaced for C1622?
No. The verified Hyundai bulletin states that the full C-MDPS assembly is not to be replaced for this diagnostic path.
What should be checked for C1622?
The verified bulletin directs checking the EMS (Engine ECU). A later Hyundai flowchart also directs checking R-MDPS connectors and wiring, clearing DTCs, and re-checking.
Is C1622 safe to drive with?
Not yet established by verified evidence.
Does C1622 affect EV charging?
Not yet established by verified evidence.