Tesla FSD v14 Lite Update Causes Overheating in HW3 Vehicles
Following Tesla's rollout of FSD v14 Lite software to HW3 vehicles in July 2026, numerous owners in China reportedly experienced overheating failures and complete computer failures, with the system triggering thermal fault codes and forcing autonomous driving shutdown.
What happened
Tesla began distributing FSD v14 Lite software to HW3-equipped vehicles in late June 2026, with full rollout after software version 2026.20.6.11 on 21 July 2026. FSD v14 Lite is a compressed version of the HW4 v14 model optimised to run on the AI3 chip in HW3 vehicles, which have 8 GB of memory and bandwidth approximately one-eighth that of HW4.
Following the full rollout, numerous vehicle owners reported Autopilot computer overheating warnings, with the ECU triggering the APP_w141_ECU_Thermal fault code when main board temperature exceeded 90°C, with some measurements reaching 96°C. In severe cases, owners reported the computer completely freezing, requiring replacement at Tesla service centres.
Reported impact
In actual driving, overheating manifested as a red double-hand icon, forced FSD shutdown and entry into selfDriving Unavailable status until the computer cooled. Some vehicle owners reported complete computer failure requiring hardware replacement.
Index analysis
The timing of concentrated fault reports coincided with FSD v14 Lite installation and increased after the full rollout, suggesting correlation with the software update. The v14 Lite model places greater computational demands on already thermally constrained HW3 hardware, and although thermal fault codes have existed for years previously, the resource-intensive model may have accelerated hardware degradation.
Governance controls
Tesla previously acknowledged HW3 cannot deliver the autonomous driving capability promised at sale and stated it would replace computers or compensate approximately 4 million vehicle owners, but has not announced a clear implementation plan. Tesla has not confirmed that the software caused hardware damage.
Classification
Sources and evidence
This record was researched and written by the Index, based on the following original reporting.