Check/add coolant

[Beebrain]

I recently got a “Coolant Level Low” warning on my dashboard. I found all the YouTube videos lacking, so I made my won:

 

[maximizese]

I had the warning when I first bought our 11/13 built S85 used from Tesla with just under 60K miles. I brought it to the Service Center the following day and they checked the logs and ran some tests. About 6 months later I noticed the DU making a milling sound, and 6 months after that the regenerative braking system was disabled, top speed and acceleration was reduced, and the car wouldn't restart.

Tesla Service replaced the DU, HV contactors, pyro fuse, and retrofitted the HVAC drain hose all under warranty. I'll never know if the low coolant warning meant there was a coolant leak to the DU (inverter) or if the leak was somewhere else, but what I do know is that the coolant system is a closed loop so there shouldn't be low coolant unless there's a leak somewhere or there was insufficient coolant put in from the factory.

It probably would be a good idea to pull the speed sensor plug from the exterior of the DU and place a borescope to see if there's any coolant in the chamber.

 

[ucmndd]

I had the warning when I first bought our 11/13 built S85 used from Tesla with just under 60K miles. I brought it to the Service Center the following day and they checked the logs and ran some tests. About 6 months later I noticed the DU making a milling sound, and 6 months after that the regenerative braking system was disabled, top speed and acceleration was reduced, and the car wouldn't restart.

Tesla Service replaced the DU, HV contactors, pyro fuse, and retrofitted the HVAC drain hose all under warranty. I'll never know if the low coolant warning meant there was a coolant leak to the DU (inverter) or if the leak was somewhere else, but what I do know is that the coolant system is a closed loop so there shouldn't be low coolant unless there's a leak somewhere or there was insufficient coolant put in from the factory.

It probably would be a good idea to pull the speed sensor plug from the exterior of the DU and place a borescope to see if there's any coolant in the chamber.

OP says they have a 100D so no large rear drive unit and no speed sensor to check.

That said I generally agree, the coolant is going somewhere, best find out where. You should never need to top it off under normal circumstances.

 

[dmurphy]

Sometimes it's really as simple as a leaky valve. Had a 3-way valve go south on our 2020 Model X; caused low coolant light. Was an easy fix ...