20 Sep 2024, 15:06 UTC • By: Photo: @OwenSparks_ via X With the refreshed Model 3, Tesla relocated the communications module from the infotainment system's PCB to a new module called the Telematics Control Unit. However, quite a few Tesla Model 3 (refreshed) owners complained about communication errors, and so far, Tesla hasn't figured out what causes them. We first heard about Tesla's new Telematics Control Unit in November 2023, when the EV maker launched the refreshed Model 3 in Europe and Asia. Back then, a discovery made by the white-hat hacker Green alarmed security researchers, who considered that the new Model 3 was much easier to steal than the previous model. Specifically, Tesla removed the communication chips from the infotainment system's PCB and installed them onto a dedicated module called the Telematics Control Unit, or TCU. The TCU includes not only the LTE modem but also the Wi-Fi and Bluetooth chips, serving as an all-in-one connectivity solution. Instead of being integrated into the infotainment system, the TCU is placed in the headliner and connected to the infotainment system via a Gigabit Ethernet interconnect. This makes it much easier for thieves to disable it, thus preventing owners and law enforcement forces from locating the vehicle remotely. Although Tesla EVs have consistently ranked among the least stolen vehicles in the US, they have been sometimes on the car thieves' radar. One theft ring taken down last year used to disable the embedded GPS modules in the stolen Teslas to prevent them from revealing the vehicle's location. While the GSM module is still located in the rearview mirror housing as before, the modem relaying the location information to Tesla servers is now placed in the headliner. As controversial as the new TCU position is, Tesla owners discovered that this is hardly its only problem. Many refreshed Model 3 owners recently complained that their TCUs are malfunctioning. This resulted in non-functional LTE, Wi-Fi, and Bluetooth connections. So far, what's causing these issues is unclear, especially as Tesla is still looking for a solution. In some cases, Tesla replaced the TCU, which only proved a temporary solution. After working normally for a while, the new module was affected by the same mysterious issues. Some suspect a poor Gigabit connection could be the culprit, while others claim a recent software update may have caused the problem. Whatever it is, Tesla has no fix and no ETA for a fix. Those who had their TCU replaced wrote on social media that they had to wait a very long time before a new module was available. One Model 3 Performance wrote on Reddit that the service center replaced a coaxial cable. This seemed to fix the problem, with the car behaving normally for more than a month. However, the connectivity died completely on September 14 while pulling away from their driveway. The symptoms were the same: lost Bluetooth, LTE, and Wi-Fi connections. In a recent reply to a Tesla Motors Club member, a Tesla Service Center technician confirmed that the connectivity issues are a "known firmware issue," but there's no solution yet. Hopefully, this means that Tesla ruled out hardware as the cause of the problem and will now focus on fixing the software. If you liked the article, please follow us: