Low coolant warning on my 2017 Model S – what should I check?

ClearTheCode admin answer:

Receiving a 'Low Coolant' warning in your 2017 Tesla Model S is a serious alert that requires prompt attention. While EVs don't have an engine in the traditional sense, they have sophisticated thermal management systems that rely on specialized coolant to keep the battery, motors, and power electronics at optimal operating temperatures.

Here's what you need to know:

1. Coolant System Complexity: Tesla's cooling system is highly integrated and complex, using specific coolants designed for electrical components and varying temperatures. It's not like a conventional internal combustion engine's cooling system.
2. Type of Coolant: Tesla vehicles use a specific type of ethylene glycol-based coolant that is typically blue or pink/purple. Do NOT use standard automotive coolant or mix different types. Using the wrong coolant can cause severe damage to the system components.
3. Checking Levels (with caution): While there are coolant reservoirs, they are often under pressure and contain high-voltage components nearby. For most owners, checking the level beyond a quick visual inspection of the main reservoir (if easily accessible and clearly marked) is not recommended due to safety and complexity.

Common Causes for Low Coolant:

• Slow Leak: The most common cause is a small leak in a hose, fitting, radiator, or other component within the closed system. These can be hard to spot without specialized tools.
• Evaporation/Permeation: Over many years, a very small amount of coolant can be lost through evaporation or permeation through hoses, though this is less common for significant drops.
• Component Failure: Less commonly, a failure in a pump, valve, or heat exchanger could lead to coolant loss.

When to See a Shop:

• Immediately: A 'Low Coolant' warning is not something to ignore. Continuing to drive with insufficient coolant can lead to overheating of critical components (battery, motors, power electronics), potentially causing irreversible damage and very costly repairs.
• Professional Service is Key: Due to the specialized coolant, the complexity of the system, and the high-voltage components involved, it is strongly recommended to schedule a service appointment with Tesla immediately. They have the correct coolant, diagnostic tools to pinpoint leaks, and the expertise to safely refill and bleed the system. Attempting to top off with incorrect fluid or without proper bleeding can introduce air into the system, leading to further issues.