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Tesla UMC_w018

Charge rate reduced - Handle temperature high Check charge handle or charge port for debris

Common search variants: UMCw018 · UMC-w018 · UMC w018 · Search ignores case and common separators.

DriveNot yet established by verified evidence.
ChargeCharging is not stated to be prohibited. Verified evidence states that charge current has been temporarily reduced; whether charging can continue in every situation is not yet established by verified evidence.
ServiceService-required status is unknown in the database. Contact Tesla service if the alert persists or further diagnosis is needed.
Confidence95%

Quick answer

Tesla alert UMC_w018 means charging current has been temporarily reduced because the Mobile Connector detected increased temperature in the handle connected to the vehicle charge port. Check that the Mobile Connector is fully inserted and check the charge handle and charge port for debris.

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 UMC_w018 mean?

Tesla alert UMC_w018 means charging current has been temporarily reduced because the Mobile Connector detected increased temperature in the handle connected to the vehicle charge port. Check that the Mobile Connector is fully inserted and check the charge handle and charge port for debris.

2. Technical explanation

Verified Tesla owner-manual material filed with NHTSA states that UMC_w018 is triggered when the Mobile Connector detects increased temperature in the charge handle that connects to the vehicle’s charge port. The resulting action is a temporary reduction in charge current.

3. What system is affected?

Mobile Connector charge handle and the vehicle charge-port connection.

4. How serious is this code?

The database severity is unknown. Verified evidence establishes reduced charging current, but does not assign a severity level.

5. Symptoms you may notice

  • The UMC_w018 alert is displayed: “Charge rate reduced - Handle temperature high Check charge handle or charge port for debris.”
  • Charge current is temporarily reduced.

6. Possible causes

  • Increased temperature detected by the Mobile Connector in the charge handle connected to the vehicle charge port.
  • Debris at the charge handle or vehicle charge port is identified in the alert text as an item to check. A causal role is not otherwise established by the verified evidence.

7. Can I still drive the vehicle?

Not yet established by verified evidence.

8. Can I charge the vehicle?

Charging is not stated to be prohibited. Verified evidence states that charge current has been temporarily reduced; whether charging can continue in every situation is not yet established by verified evidence.

9. What you can safely do

  • Make sure the Mobile Connector is fully inserted.
  • Check the charge handle and vehicle charge port for debris.

10. Step-by-step troubleshooting

  1. Confirm that the Mobile Connector is fully inserted.
  2. Inspect the charge-handle and charge-port connection for debris, as directed by the alert.
  3. If further diagnosis or repair is needed, contact Tesla service. Detailed diagnostic or high-voltage repair procedures are not established by the verified evidence.

11. When to contact service

Service-required status is unknown in the database. Contact Tesla service if the alert persists or further diagnosis is needed.

12. What the service center may check

  • Verify that the Mobile Connector is fully inserted.
  • Check the charge handle and vehicle charge port for debris. Additional service checks are not yet established by verified evidence.

13. Possible repair or resolution

  • Not yet established by verified evidence.

14. Affected vehicles

15. Related TSBs / service bulletins

  • NHTSA Manufacturer Communication PDF 10253660: Index381 (published 2024-03-26): https://static.nhtsa.gov/odi/tsbs/2024/MC-10253660-9999.pdf
  • NHTSA Manufacturer Communication PDF 10250483: ManualC (published 2023-12-01): https://static.nhtsa.gov/odi/tsbs/2023/MC-10250483-9999.pdf
  • NHTSA Manufacturer Communication PDF 10238120: Manual-2 (published 2023-05-22): https://static.nhtsa.gov/odi/tsbs/2023/MC-10238120-9999.pdf

16. Recall information

  • Not yet established by verified evidence.

17. Official manufacturer information

Official NHTSA-hosted Tesla owner-manual communications describe UMC_w018. The verified applicability data covers US Tesla Model 3 (2017–2023), Model S (2012–2023), and Model X (2016–2023).

19. Frequently asked questions

What does Tesla UMC_w018 mean?

It means charge current has been temporarily reduced because the Mobile Connector detected increased temperature in the handle connected to the vehicle charge port.

What should I check for UMC_w018?

Make sure the Mobile Connector is fully inserted and check the charge handle and charge port for debris.

Does UMC_w018 mean the car cannot be driven?

Not yet established by verified evidence.

Which vehicles are covered by the verified applicability data?

US Tesla Model 3 model years 2017–2023, Model S model years 2012–2023, and Model X model years 2016–2023.

20. Sources & verification

Verified
Show all 24 verified sources
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