Title: Openai/69556a65-a290-8002-a217-eebca2e0b967 - freem URL Source: https://freemwiki.com/index.php?oldid=595063&title=Openai%2F69556a65-a290-8002-a217-eebca2e0b967 Markdown Content: (diff) ← Older revision | Latest revision (diff) | Newer revision → (diff) _This conversation was exported from ChatGPT_[[1]](https://freemwiki.com/index.php?oldid=595063&title=Openai%2F69556a65-a290-8002-a217-eebca2e0b967#cite_note-1) ## gpt-5-2[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=1 "Edit section: gpt-5-2") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=1 "Edit section's source code: gpt-5-2")] ### User: 2020 Lexus RX 350 F-Sport with over 47K miles and recently noticed that on occasions when I may need to accelerate and …[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=2 "Edit section: User: 2020 Lexus RX 350 F-Sport with over 47K miles and recently noticed that on occasions when I may need to accelerate and …") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=2 "Edit section's source code: User: 2020 Lexus RX 350 F-Sport with over 47K miles and recently noticed that on occasions when I may need to accelerate and …")] 2020 Lexus RX 350 F-Sport with over 47K miles and recently noticed that on occasions when I may need to accelerate and it will start to redline and temporarily get stuck and not drop back down to normal rpm’s . ### Assistant: That behavior on a 2020 Lexus RX 350 F-Sport 47k miles is not normal and usually points to a transmission or throttle c…[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=3 "Edit section: Assistant: That behavior on a 2020 Lexus RX 350 F-Sport 47k miles is not normal and usually points to a transmission or throttle c…") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=3 "Edit section's source code: Assistant: That behavior on a 2020 Lexus RX 350 F-Sport 47k miles is not normal and usually points to a transmission or throttle c…")] That behavior on a 2020 Lexus RX 350 F-Sport (47k miles) is not normal and usually points to a transmission or throttle control issue, most commonly related to how the 8-speed automatic is managing shifts. Below are the most likely causes, starting with the most common for this model/year. #### Most Likely Causes[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=4 "Edit section: Most Likely Causes") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=4 "Edit section's source code: Most Likely Causes")] ##### 1. Transmission Hesitation / Shift Logic Issue (Very Common on RX)[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=5 "Edit section: 1. Transmission Hesitation / Shift Logic Issue (Very Common on RX)") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=5 "Edit section's source code: 1. Transmission Hesitation / Shift Logic Issue (Very Common on RX)")] Lexus RX models (2019–2021 especially) are known for: * Delayed upshifts * RPMs climbing to redline * Transmission “holding” a gear too long before finally shifting This often happens: * During quick acceleration * When merging or passing * After slowing and re-accelerating 📌 Why it happens * Transmission software struggles to decide which gear to select * The ECU thinks you still want maximum power * More noticeable in Sport or Sport+ mode ✅ Fix * Lexus TSB (software update) often resolves this * Dealer reflash of the transmission control module ##### 2. Throttle Position Sensor or Electronic Throttle Body Issue[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=6 "Edit section: 2. Throttle Position Sensor or Electronic Throttle Body Issue") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=6 "Edit section's source code: 2. Throttle Position Sensor or Electronic Throttle Body Issue")] If the car: * Revves high * Doesn’t immediately respond when you lift off the gas * Feels like it’s “stuck” revving This could be: * Dirty throttle body * Faulty throttle position sensor * Accelerator pedal sensor lag ✅ Fix * Throttle body cleaning * Sensor recalibration or replacement (if faulty) ##### 3. Torque Converter Not Locking Properly[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=7 "Edit section: 3. Torque Converter Not Locking Properly") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=7 "Edit section's source code: 3. Torque Converter Not Locking Properly")] A failing or slipping torque converter can cause: * RPMs to flare upward * Delayed power transfer * RPMs staying high even when speed isn’t increasing much 📌 Often intermittent at first, then becomes frequent. ⚠️ More serious if ignored. ##### 4. Transmission Fluid Condition[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=8 "Edit section: 4. Transmission Fluid Condition") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=8 "Edit section's source code: 4. Transmission Fluid Condition")] Even though Lexus markets it as “lifetime fluid”: * At ~47k miles, fluid can already degrade * Old fluid can cause erratic shifting and RPM flare ✅ Fix * Drain-and-fill (NOT a flush) * Lexus Type WS fluid only ##### 5. Drive Mode Effect[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=9 "Edit section: 5. Drive Mode Effect") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=9 "Edit section's source code: 5. Drive Mode Effect")] In Sport / Sport+: * Transmission intentionally holds gears longer * RPMs stay higher by design 📌 If this happens in Normal or Eco, it’s more concerning. #### What You Should Do Next (In Order)[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=10 "Edit section: What You Should Do Next (In Order)") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=10 "Edit section's source code: What You Should Do Next (In Order)")] ##### Step 1: Note the Conditions[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=11 "Edit section: Step 1: Note the Conditions") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=11 "Edit section's source code: Step 1: Note the Conditions")] Tell the dealer: * Which drive mode (Normal / Sport / Sport+) * Happens when warm or cold * Happens during passing / merging * How long RPMs stay high ##### Step 2: Ask Dealer to Check for TSB / Software Update[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=12 "Edit section: Step 2: Ask Dealer to Check for TSB / Software Update") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=12 "Edit section's source code: Step 2: Ask Dealer to Check for TSB / Software Update")] Specifically request: “Check for transmission ECU or powertrain software updates related to shift hesitation or RPM flare.” This alone fixes many RX complaints. ##### Step 3: Request a Transmission Diagnostic[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=13 "Edit section: Step 3: Request a Transmission Diagnostic") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=13 "Edit section's source code: Step 3: Request a Transmission Diagnostic")] Ask them to check: * Live shift data * Torque converter lock-up * Throttle input vs RPM response ##### Step 4: Consider Transmission Fluid Service[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=14 "Edit section: Step 4: Consider Transmission Fluid Service") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=14 "Edit section's source code: Step 4: Consider Transmission Fluid Service")] Even if Lexus says it’s lifetime, many techs recommend: * Drain & refill at 50–60k miles #### 🚨 When It’s Urgent[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=15 "Edit section: 🚨 When It’s Urgent") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=15 "Edit section's source code: 🚨 When It’s Urgent")] Go to the dealer ASAP if you notice: * RPMs stay high even after lifting off gas * Harsh shifts afterward * Burning smell * Check engine or transmission warning #### Bottom Line[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=16 "Edit section: Bottom Line") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=16 "Edit section's source code: Bottom Line")] ✔ Most likely cause: transmission software or shift logic ✔ Good news: often fixed with a software update ⚠️ Do not ignore — prolonged RPM flare can damage the transmission If you want, tell me: * Does it happen in Normal mode? * How long do RPMs stay high (seconds)? * Any warning lights? I can narrow this down further. ## References[[edit](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&veaction=edit§ion=17 "Edit section: References") | [edit source](https://freemwiki.com/index.php?title=Openai/69556a65-a290-8002-a217-eebca2e0b967&action=edit§ion=17 "Edit section's source code: References")] 1. [↑](https://freemwiki.com/index.php?oldid=595063&title=Openai%2F69556a65-a290-8002-a217-eebca2e0b967#cite_ref-1 "Jump up")["Lexus RX 350 RPM Issue"](https://chatgpt.com/share/69556a65-a290-8002-a217-eebca2e0b967). ChatGPT. Retrieved 2026-01-01.