The NHTSA is Looking at Potential Safety Issues Involving Faulty Heat Pumps in Tesla Vehicles

author: FutureCar Staff    

As the world's most valuable automaker, Tesla seems to be under extra scrutiny whenever a problem is discovered with one of its vehicles, no matter how small. Among Tesla's past problems were underperforming brakes, faulty display screens and electrical problems, and of course Tesla's self-driving capabilities, which have been blamed for fatal accidents

Now the company is under investigation once again by The U.S. National Highway Traffic Safety Administration (NHTSA) after reports of customers in Canada having problems with the heat pumps in their vehicles. The problem is exacerbated in extremely cold climates, where the heat pump is used to quickly defrost the windows. 

Transport Canada said it is concerned that a malfunctioning heating and air-conditioning system "may affect windshield defogging/defrosting and therefore driver visibility."

The NHTSA said it "is aware of the issue and is continuing to gather information, discuss the issue with Tesla and evaluate potential safety concerns."

A number of Tesla owners have complained that heat pumps are failing in extreme cold temperatures, according to website Drive Tesla Canada. The Tesla owners were left without heat in temperatures as low as -40 degrees Celsius. Some of these owners lodged complaints directly with Transport Canada.

Tesla's electric vehicles do not have a gas engine and a pressurized cooling system to keep the internal combustion engine cool like a regular car. For gas-powered vehicles, the hot antifreeze and water mixture is used to heat the cabin. So Tesla uses a heat pump to quickly warm up the cabin for passengers and for the window defrosters when the temperature drops.

The heat pump in the Model Y works like an air conditioner condenser, except in reverse. Instead of removing heat like an air conditioning system does, the heat pump transfers heat into the cabin. Tesla also used a liquid cooling system for the battery pack. Some of the heat created by the batteries is redirected into the cabin in cold weather using what Tesla calls an "Octavalve" that uses liquid coolant.

The report from the NHTSA said the heating problems happened even after Tesla early last year replaced faulty sensors in heat pumps in some 2020-2021 Model 3 and Model Y vehicles to address the issue.

Tesla has not commented on the matter.

Canada's auto safety regulator opened its investigation into the heating and cooling system performance of Tesla Model 3 and Model Y vehicles after receiving 16 consumer complaints about poor performance in cold weather.

FutureCar Staff