Tesla to roll out software update to fix windshield defrosting issue on 26k vehicles

(Credit: Jerry Rig Everything)

Tesla is rolling out an over-the-air software update that would allow the company to address a windshield defrosting issue present in vehicles that are equipped with a heat pump. A total of 26,681 vehicles are affected by the issue, according to the National Highway Traffic Safety Administration’s (NHTSA) Safety Recall Report. 

Vehicles that are part of the “recall” include 2021-2022 Tesla Model S, 2020-2022 Tesla Model Y, 2021-2022 Tesla Model 3, and 2021-2022 Tesla Model X. The US regulator noted in its Safety Recall Report that a software error in the affected vehicles may cause a valve at the cars’ heat pumps to open unintentionally, resulting in refrigerant being trapped inside the evaporator. This could adversely affect a vehicle’s defrosting performance. 


While the issue is quite notable, Tesla notes that it is not aware of any crashes, injuries, or fatalities related to the affected vehicles’ heat pump issue. 

A chronology of the heat pump issue was outlined in the NHTSA’s Safety Recall Report. As per the document, Tesla began rolling out firmware release 2021.44 and subsequent releases through firmware release 2021.44.30.6 to affected vehicles on or about December 10, 2021. Later that month, the company started receiving complaints from customers about the loss of heating performance in extreme weather conditions. 

An investigation to find the root cause of the issue was commenced then. By January 11, 2022, it was determined that the lack of software command to close the Electronic Expansion Valve (EXV) after communication interruptions in firmware release 2021.44 through 2021.44.30.6 was a potential cause of the problem. Software update 2021.44.30.7 and later releases, which reintroduced a software command to close the EXV, was rolled out on January 15, 2022, as a precautionary measure. 

Tesla Model 3, Model Y HVAC investigation in Canada still ongoing after 171 consumer complaints

Following discussions with the NHTSA’s Office of Vehicle Safety Compliance and Transport Canada about consumer complaints, Tesla conducted tests to assess the compliance of new vehicles delivered with the software command found in firmware release 2021.44 through 2021.44.30.6. Unfortunately, the results of these tests revealed that new vehicles delivered with firmware release 2021.44 through 2021.44.30.6 may still present issues in worst-case scenarios.

After confirming the root cause of the issue, a recall determination was made for the affected vehicles on January 26, 2022, the final day of the compliance tests. The affected vehicle population for the recall was then expanded out of an abundance of caution on February 7, 2022, to incorporate vehicles that are currently running firmware release 2021.44 through 2021.44.30.6, but are yet to install firmware release 2021.44.30.7 or later. 

The remedy for the issue was outlined in the NHTSA’s Safety Recall Notice. As per the document, the fix for the issue would be rolled out through firmware release 2021.44.30.7. The update, similar to Tesla’s other key patches for its vehicles, would be released over-the-air and completely free of charge. 

“Firmware release 2021.44.30.7 and later releases remedy the condition by reintroducing a software command to close the EXV, thereby preventing refrigerant from entering the evaporator. No further action is necessary from owners whose vehicles are equipped with firmware release 2021.44.30.7 or a later release. 

“Tesla does not plan to include a statement in the Part 577 owner notification about reimbursement for pre-notice repairs to owners since all of the affected vehicles remain covered under the new vehicle warranty, and owners will receive the remedy free of charge with an OTA firmware release.”

The NHTSA’s Safety Recall Report for Tesla’s heat pump issue can be viewed below. 

RCLRPT-22V050-2023 by Simon Alvarez on Scribd

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Tesla to roll out software update to fix windshield defrosting issue on 26k vehicles
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