Am I the only one getting false unable to charge message

Am I the only one getting false unable to charge message

When I plug my car into my 240 volt outlet I get a message that it is unable to charge. Then it starts charging at a lower amperage and alternates throw in unable to charge messages and charging at a lower amperage. These keep repeating until the car is fully charged. It started immediately after the latest update but only on my car. I was told that the latest update is more sensitive to fluctuations in the electrical line. They replaced the on board charger but it still happens. So I need to have the line checked but have no idea what to ask the electrician to check for. Any ideas?

Redmiata98 | 14. toukokuu 2019

Have an electrician check your lines?

Vawlkus | 15. toukokuu 2019

It’s either a grounding issue, or one of the neutral lines was left off when the plug was installed. I see this at a couple of L2 chargers. | 15. toukokuu 2019

While Tesla doesn't use the neutral line, so a problem there is not the cause. As Vawlkus noted, it could be a grounding issue. Other things to look for are a loose connection between the wires and the outlet, or the wires and the breaker. Normally the wire is a single run from the breaker to the outlet, but if there was a splice in the line (i.e. junction box), I'd carefully check each wire nut is properly attached.

Also check if aluminum wire used (not recommended, but allowed). It requires breakers and outlet connectors are rated for aluminum and properly torqued and anti-oxidant goo applied.

David Trushin | 15. toukokuu 2019

Thanks folks. Now I have something to talk to the electricuian about.

Saxman | 16. toukokuu 2019

I am having a similar problem.

My Dec 2016 MX75D has been plugged in, in my garage continuously since April 1. I set it to Charge when the battery drops below 75%. It has been Charging accordingly up until a several days ago.

When I look at the Charging Screen, on the Tesla App, now it says..."Ready to Charge. Check power source".

The battery is draining about 6 miles per day, and is about 37% SOC. I will not be back to that home until July 1st.

I'm trying to get a neighbor to check out the situation and hopefully a circuit breaker reset will suffice. If that doesn't fix problem does anyone have other suggestions.

I have a NEMA 14-50 OUTLET and the Corded Mobile Connector.

All suggestions welcomed.

David Trushin | 16. toukokuu 2019

To isolate the problem you can try plugging into a 110 volt outlet, the a public charger, supercharger, someone else's 240. Also check to see if the green light is on in the charger box near the plug and try resetting the box. I think there is also a fuse in the plug that you can check. If you call service, they will prioritize cars that don't charge, and if you drive it got a service center and it won't charge they'll take it right away.

Saxman | 18. toukokuu 2019


Thanks for your suggestions. Unfortunately I am 1100 miles away and won't return till July 1st.

I'm hoping a neighbor will go to my home and we can troubleshoot over the phone.

In 2.5 yrs ownership I never noticed the RESET BUTTON. Is it on reverse side of Box for the plug that goes into Nema 14-50 outlet?


David Trushin | 18. toukokuu 2019

Yes. On the black side.

Saxman | 18. toukokuu 2019

Thanks David

David Trushin | 21. toukokuu 2019

Well, Kapital electric came and rewired my connector. It wasn't wired correctly. However I still get the erroneous unable to charge and reduced charge rate, but only intermittently. One is definitely a firmware bug because the car always charges normally a d I suspect the at the reduced charge charge rate is triggered by the bug firing off. Given that it's intermittent, it's probably some funky timing issue.