Now that the National Highway Traffic Safety Administration (NHTSA) has issued a recall related to issues with heat loss in some Tesla vehicles, we have a better idea of the problem. Moreover, Tesla is reportedly already rolling out a "fix" for the issue.
Despite some reports stating otherwise, NHTSA learned that the problem does involve Tesla's heat pump, which is why some owners started having issues with a lack of heat and proper defrosting in frigid temperatures last winter. Tesla added the heat pump as standard equipment in the updated Model 3 after the Model Y came to market equipped with a heat pump.
Tesla claimed over the last month or so that it's prioritizing a fix for the heat pump issue, which it will deliver via an over-the-air software update. In fact, the automaker already issued some updates, though some owners noted that the problem still existed after the software was updated. According to recall information released by NHTSA via Electrek:
“Windshield defrost performance that does not fully comply with FMVSS 103 may cause reduced windshield visibility in certain conditions, which may increase the risk of a collision. Tesla is not aware of any crashes, injuries or fatalities related to this condition.”
As we previously reported, NHTSA was investigating the situation to determine if it was a safety issue. Since impacted Tesla owners may not be able to see clearly out of their windshields, and the defrost performance doesn't comply, a recall has been issued. It reads as follows:
NHTSA explains the problem in detail in the new recall notice entitled "Windshield May Not Defrost Properly/FMVSS 103." The organization adds that this is occurring in Tesla's vehicles manufactured with a heat pump, and that the "Electronic Expansion Valve (EXV) may experience controller communication interruptions." The recall summary reads as follows:
"Decreased defrosting performance may reduce the driver's visibility, increasing the risk of a crash."
"Tesla, Inc. (Tesla) is recalling certain 2021-2022 Model 3, Model S, Model X, and 2020-2022 Model Y vehicles. A software error may cause a valve in the heat pump to open unintentionally and trap the refrigerant inside the evaporator, resulting in decreased defrosting performance. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 103, "Windshield Defrosting and Defogging Systems."
NHTSA's Safety Recall Notice also explains the solution for the problem. Tesla is rolling out firmware update 2021.44.30.7 via an over-the-air software update. Essentially, the software update, along with subsequent releases, will reintroduce "a software command to close the EXV, thereby preventing refrigerant from entering the evaporator."
We can only hope that the latest update completely solves the problem. However, NHTSA's explanation specifically states, "Firmware release 2021.44.30.7 and later releases," which seems to suggest it may take multiple updates to solve the issue.