MyTeslaMate
UMC family

UMC_a006_contactorWelded

Unable to charge - Mobile Connector error

What does the UMC_a006_contactorWelded alert mean?

UMC detected contactor stuck open or closed

What you'll see in your Tesla

  • Unable to charge - Mobile Connector error
  • Unplug from wall outlet and retry

What triggers it

UMC contactor is open when it should be closed (non-EU smart adapter) or closed when it should be open for several seconds

When it clears

UMC contactor is in the expected state for several seconds

Potential impact

UMC will not allow charging if the contactor is stuck in an unexpected state. Charge handle pins may be live and hazardous. Stuck open (non-hazardous) contactors will not trigger this fault with EU smart adapters.

Affected models

Cybertruck Model 3 2017-2023 Model 3 2024+ Model S 2021+ Model X 2021+ Model Y Model Y 2025+

Track your Tesla's alerts automatically

Alerts like this reach MyTeslaMate through your car's Tesla telemetry API. MyTeslaMate logs every alert your Tesla reports and turns it into readable history and real-time notifications — hosted TeslaMate with no server to run.