Check power source and charging equipment
Charging speed has been reduced due to a condition that affects your vehicle's ability to charge with AC power. DC fast charging / Supercharging should still function as expected.
Your vehicle's onboard charger has detected that one or more power converters is not receiving the necessary AC input voltage. For example: during three-phase charging, one phase might be missing from the AC input power provided by the external source. This could occur due to a condition affecting the external charging equipment, the power source it is connected to, or your vehicle itself.
As this alert is usually specific to external charging equipment and power sources, and it does not typically indicate an issue with your vehicle that can be resolved by scheduling service, it is recommended that you try charging with multiple, different types of charging equipment.
You can also try charging your vehicle using a Tesla Supercharger or Destination Charging location, all of which can be located through the map on your vehicle's touchscreen display. See Maps and Navigation for more details. Additional third-party charging stations may also be available in your area to help you to pinpoint the issue.
For more information on troubleshooting Mobile Connector or Wall Connector status lights, refer to the product's Owner's Manual at Charging & Adapter Product Guides. If using other external charging equipment, refer to the manufacturer's provided documentation for troubleshooting tips.