Tesla Model X thermal system repair: a corroded AC pipe and a broken radiator shutter
A Model X came in with an air conditioning fault and a radiator shutter broken by road debris. Here is how we found a corroded rear AC pipe, and why thermal management matters so much on a Tesla, in winter as well as summer.
personBy Gabor, MegaEV calendar_today 3 min read
We recently had a Tesla Model X in with two problems. The instrument cluster was showing an air conditioning fault, and the radiator shutter at the front had been broken by road debris.
Finding the AC fault
We started by diagnosing the AC system and running a full thermal test. That showed insufficient refrigerant pressure, so refrigerant was escaping somewhere.
On a Model X with rear climate control, a common cause is corrosion in the long refrigerant pipe that runs from the front of the car to the rear. A nitrogen pressure test confirmed exactly that: the rear AC pipe had corroded and developed a leak.
The repair
- replaced the corroded rear AC pipe
- replaced the faulty radiator shutter
- carried out a full AC regas
The car's thermal management system is now working exactly as it should.
Why thermal management matters so much on a Tesla
On a petrol car, a broken air conditioning system is mostly a comfort problem. On a Tesla, it is more than that. This car had two separate issues, and each one shows a different side of it.
A non-working AC system, even in winter
Working air conditioning is essential all year round. It:
- dries the cabin air and prevents condensation
- reduces moisture build-up inside the car, which protects the electronics on board from corrosion, such as the on-board charger, the Autopilot computer and the MCU
- helps cool the battery during DC rapid charging, so the car can keep charging at its best speed
Without proper AC performance, both comfort and charging speed suffer.
A faulty radiator shutter, in any season
The radiator shutter controls how much air flows through the radiator.
In winter, if the shutter is stuck open, the car can overcool. The PTC heater then has to work harder to warm the cabin, which reduces range and wears the heating components faster, including the battery heater.
In warmer weather, a shutter that does not work causes the opposite problem:
- reduced cooling efficiency
- the AC compressor working harder
- the coolant pumps running at maximum speed
- a risk of overheating the water-cooled units, such as the on-board charger, the Autopilot computer, the drive units and the high-voltage battery
Never just an AC issue
Thermal management faults on an electric car are never just an AC issue. They affect performance, charging speed, efficiency and the long-term reliability of expensive components. See our air conditioning and thermal management service for more.
If your Tesla is showing an AC or thermal warning, or is charging more slowly than it should, send us a message and tell us what you are seeing.
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