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Tesla UMC_a013

Wall plug adapter error - Charge rate reduced Plug adapter fully into Mobile Connector and retry

Common search variants: UMCa013 · UMC-a013 · UMC a013 · Search ignores case and common separators.

DriveNot yet established by verified evidence.
ChargeYes, verified evidence states charging current is automatically reduced to 8A. Whether charging will continue in an individual case is not otherwise established by verified evidence.
ServiceNot yet established by verified evidence.
Confidence95%

Quick answer

UMC_a013 means the Tesla Mobile Connector cannot communicate with its wall plug adapter. Charging current is automatically reduced to 8A because the connector cannot monitor adapter temperature. Unplug the Mobile Connector, fully insert the wall plug adapter, and retry charging.

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1. What does UMC_a013 mean?

UMC_a013 means the Tesla Mobile Connector cannot communicate with its wall plug adapter. Charging current is automatically reduced to 8A because the connector cannot monitor adapter temperature. Unplug the Mobile Connector, fully insert the wall plug adapter, and retry charging.

2. Technical explanation

Tesla’s documented meaning for UMC_a013 is “Wall plug adapter error - Charge rate reduced.” The Mobile Connector is unable to communicate with the wall plug adapter. As a result, it reduces charging current to 8A because it cannot monitor the adapter’s temperature.

3. What system is affected?

Tesla Mobile Connector and wall plug adapter.

4. How serious is this code?

The database does not assign a severity. Verified evidence establishes reduced charging current to 8A, not a vehicle-driveability condition.

5. Symptoms you may notice

  • The vehicle displays UMC_a013: “Wall plug adapter error - Charge rate reduced.”
  • Mobile Connector charging current is automatically reduced to 8A.

6. Possible causes

  • The Mobile Connector is unable to communicate with the wall plug adapter.
  • Not yet established by verified evidence: the specific underlying reason for the communication failure.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Yes, verified evidence states charging current is automatically reduced to 8A. Whether charging will continue in an individual case is not otherwise established by verified evidence.

9. What you can safely do

  • Unplug the Mobile Connector.
  • Fully insert the wall plug adapter into the Mobile Connector.
  • Retry charging.
  • Refer to the Mobile Connector product owner’s manual for status-light and charging-issue troubleshooting.

10. Step-by-step troubleshooting

  1. Follow the documented reset action: unplug the Mobile Connector, fully seat the wall plug adapter, and retry.
  2. If the alert remains, further troubleshooting steps are not yet established by verified evidence supplied.

11. When to contact service

Not yet established by verified evidence.

12. What the service center may check

  • Not yet established by verified evidence.

13. Possible repair or resolution

  • Fully seating the wall plug adapter in the Mobile Connector and retrying charging is the documented owner action.
  • Any repair, replacement, or diagnostic resolution beyond this action is not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA manufacturer communications/owner-manual publications document UMC_a013, including MC-10250484 (published December 1, 2023): https://static.nhtsa.gov/odi/tsbs/2023/MC-10250484-9999.pdf
  • These publications describe the alert and owner action; the supplied evidence does not establish a vehicle repair bulletin for this condition.

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official NHTSA-hosted Tesla manufacturer communication: https://static.nhtsa.gov/odi/tsbs/2023/MC-10250484-9999.pdf. Verified applicability records cover US Tesla Model 3 (2013–2024), Model S (2012–2024), Model X (2016–2024), and Model Y (2020–2024), with overlapping year ranges in the source database.

19. Frequently asked questions

What does Tesla alert UMC_a013 mean?

It means the Mobile Connector cannot communicate with the wall plug adapter, and charging current is reduced.

Why is charging reduced to 8A?

Tesla documentation states the Mobile Connector reduces current to 8A because it cannot monitor the wall plug adapter temperature.

What should I do for UMC_a013?

Unplug the Mobile Connector, fully insert the wall plug adapter into it, and retry charging.

Can I drive with UMC_a013?

Not yet established by verified evidence.

20. Sources & verification

Accepted ResearchVerified
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Tesla UMC_a013: Wall plug adapter error - Charge rate reduced Plug… | EV Diagnostics