My 2023 Tesla Model 3 SR+ Had Its Autopilot Computer Replaced Three Times And An Entire New Cooling System Installed, Now Tesla Says It's Just A Software Bug And All SR+ Models Are Affected

Some folks buy a car and drive it. Others, like Reddit user Tudz, buy a Tesla and find themselves enlisted in the informal ranks of field engineers. What began as a promising relationship with a 2023 Tesla Model 3 SR+ quickly evolved into an ongoing saga of shutdowns, service appointments, and system swaps. And after months of hardware replacements, including three Autopilot computers, a new radiator, pumps, lines, and an octovalve, Tesla now says it was never the hardware. It was the software all along.

"My '23 Model 3 SR+ has been plagued by an overheating autopilot computer for months, leading to crashes. This issue persisted even after three computer replacements, an octovalve, pumps, lines, and a radiator replacement (essentially the entire cooling system). Tesla technicians tested everything and confirmed that all new parts were to factory specifications; yet, the APU continued to overheat.

Last Friday, Tesla initially suggested the problem was linked to a "batch of bad computers." However, following a call from the manager, they now believe it's a firmware issue.

The Resolution Plan:

Immediate Patch: Tesla will apply a specific firmware patch only to my car for now. This patch will prevent the car from preconditioning on the way to a Supercharger.

Global OTA Update: They will then develop a broader over-the-air (OTA) patch for all '23 Model 3 SR+ vehicles worldwide (both Shanghai and American models). This update will require no action from customers, but I will be notified for feedback.

Confirmation: Tesla has confirmed an uptick in customers experiencing the same issue. My car, having undergone extensive repairs, has been instrumental in proving this is a software problem, and that computer replacements will not resolve it. Others with the overheating APU issue will receive the OTA update as their resolution. I will be among the very first customers to receive this patch (after internal staff, of course).

Compensation for My Trouble: Because my car has been used as Tesla's "guinea pig" for three months across seven visits, they have agreed to compensate me for the time my brand-new car was out of commission, as well as for wear and tear. Furthermore, since my car won't be preconditioning until this patch is released, they will provide free Supercharging credits sufficient to cover the period until the patch is deployed.

The exact compensation amounts are currently being calculated by other teams. I will receive written confirmation of the plan, including a guarantee for work done beyond the warranty period, which I can then present to my lawyer.

Basically, my "franken-Tesla" has helped save the day for other '23 Model 3 SR+ owners! The manager mentioned this situation involved the highest-level engineers he's ever spoken to in his career and garnered the highest visibility for a single car he's ever seen. This is likely because the issue borders on recall territory."

That post, shared to r/TeslaFSD, pulled back the curtain on a rarely seen side of the EV revolution: what happens when the silicon brain running your car decides it's too hot to think. Tudz’s Autopilot computer, or APU, was regularly hitting 99°C and shutting down, right in the middle of FSD sessions. In most cars, that's the moment the check engine light blinks. In a Tesla, it’s the moment you realize your AI chauffeur just walked off the job.

Tesla Recall Roundup: Model 3/Y Power‑Steering, Touchscreen Freezes, Suspension & Autopilot System Alerts

• Recent recall on Model 3 and Y due to potential loss of power-steering assist at low speeds; Tesla issued an over‑the‑air fix 
• Affects all Tesla models (including Model 3), where touchscreens could darken or freeze; recall involved OTA software patch and mailed notifications 
• Back in 2021, several Model 3s were recalled over suspension defects that could compromise stability; free repairs were offered via dealers 
• Tesla recalled parts of the Autopilot system in over 2 million vehicles (including Model 3) due to federal safety reviews, prompting corrective actions

The issue boiled down to a perfect storm: LFP battery chemistry, Autopilot use, and cool ambient temperatures, especially when the vehicle was preconditioning for Supercharging. “Unless you actually use Autopilot while preconditioning, you are fine. I do, every day,” Tudz explained. That detail, overlooked in routine diagnostics, became the Rosetta Stone for understanding a flaw that wasn’t isolated to one car, but potentially every 2023 SR+ with Hardware 3 (HW3).

Tesla's solution? A two-phase fix. First, a one-off firmware patch for Tudz that disables preconditioning during navigation to Superchargers. 

Tesla Rolls Out Global OTA Patch for 2023 Model 3 SR+ Autopilot Overheat Fix

Then, a global over-the-air (OTA) update to all affected SR+ vehicles, both American and Shanghai-built. It's a move Tesla is uniquely positioned to make thanks to its OTA architecture, which allows for software corrections without dealer visits. But it also raises an important point about what it means to own a modern vehicle: your car can change drastically, for better or worse, long after it leaves the factory.

The story caught traction because Tudz did something most customers don't: he documented every step. Flow rates. Board temps. System menus. One user, Capital-Plane7509, thanked him directly: “I have a 2023 RWD from Shanghai... I'm glad Tesla is being somewhat proactive.” Others chimed in with similar configurations but no symptoms, highlighting how specific the failure conditions were. As Tudz put it, “Conditions need to be perfect.” That level of transparency, paired with methodical observation, helped push the case up the Tesla chain of command, far higher than any single service ticket usually travels.

2023 Tesla Model 3 SR+ Specs: Dimensions, Battery Range, Charging Rates & 0‑60 mph Performance

• Measures roughly 184.8″ long, 72.8″ wide, 56.8″ tall, riding on a 113.2″ wheelbase, with a passenger volume of about 97 ft³ and 15–23 ft³ cargo capacity depending on source 
• Weighs around 4,040 lb; built on a rear- or dual-motor EV platform using Tesla’s 2170 battery cells 
• Available battery packs range 57–82 kWh, with support for up to 250 kW Supercharging (via NACS), and AC charging around 7–11 kW 
• Varies by trim, approx. 5.8 sec (RWD), 4.9 sec (LR AWD), 4.2 sec (Performance), down to ~2.9 sec in top Performance versions 

Tesla acknowledged as much. The service manager reportedly told Tudz this case involved “the highest-level engineers he's ever spoken to” and was “the highest visibility for a single car” he'd seen. And Tesla is compensating the owner, not just with words. Along with Supercharging credits to cover the loss of preconditioning, Tesla is calculating additional compensation for time lost and wear incurred across seven visits and three months of downtime. Written documentation, Tesla said, will include guarantees beyond the warranty period.

This isn't the first time software masquerading as hardware trouble has cropped up in Tesla's history. Earlier hardware transitions, from Intel Atom chips to AMD Ryzen, or from HW2.5 to HW3, sparked similar confusion until software updates or retrofits leveled the playing field.

Image Sources: Tesla Media Center

Noah Washington is an automotive journalist based in Atlanta, Georgia. He enjoys covering the latest news in the automotive industry and conducting reviews on the latest cars. He has been in the automotive industry since 15 years old and has been featured in prominent automotive news sites. You can reach him on X and LinkedIn for tips and to follow his automotive coverage.