Lexus transmission down shifting hard HELP!
Thread Starter
Driver School Candidate
Joined: Sep 2014
Posts: 16
Likes: 3
From: FL
Lexus transmission down shifting hard HELP!
Hey guys I’m really trying to figure out what’s wrong with my car, it’s a 2004 Lexus LS430 with 160k miles. It started the other day when I’m slowing down under 10mph it will just slam the car into first gear before it’s at a complete stop but very harshly and you somewhat feel 3-2 hard shift as well but 2-1 is very violent and jerky. I do not believe it is the transmission because I’ve had other cars with transmission issues and you’ll start feeling signs of slipping or other issues before it gets bad but my Lexus was good one day and acting up the next day. Please let me know if anyone has had this issue and what is the fix for it. I just took it to a shop and they said it was the transmission and 3k to fix but you know how shops are. Also there is no error codes or check engine lights and the car accelerates fine it just acts up when it’s time to downshift.
Advanced
Joined: May 2018
Posts: 647
Likes: 258
From: Ct
Lead Lap
Joined: Nov 2004
Posts: 552
Likes: 27
From: Maryland
try this before you spend any money. Worked for me and others and totally free
https://www.clublexus.com/forums/sc4...t-the-ecu.html
https://www.clublexus.com/forums/sc4...t-the-ecu.html
Trending Topics
ClubLexus Stories
Celebrating Lexus & Toyota from Around the Globe
Lexus NX 350h: A Fuel-Sipping Secret Hot Hatch???
Michael S. Palmer
5 Best & 5 Worst Lexus Daily Drivers
Joe Kucinski
Top 5 Hottest Lexus & Toyotas in 2026 (Hardest To Buy)
Brett Foote
2026 Lexus IS 350 F Sport Review: The Last of Its Kind Still Rocks
Michael S. Palmer
Top 10 Most Confusing Things Lexus Has Ever Done!
Joe Kucinski
2026 Lexus ES Review: Lexus Re-Embraces Founding Principles
Michael S. Palmer
10 Lexus Bargains That are Cheaper Than a New Toyota RAV4
Joe Kucinski
8 Weirdest Things Lexus Has Ever Built
Verdad Gallardo
10 Lexus Designs That Have Aged Like Fine Wine
Verdad Gallardo
Advanced
Joined: Dec 2017
Posts: 716
Likes: 168
From: FL
This is really sad when dealers basically defraud customer’s wallets to do some simple stuff like connecting mongoose cable and setting up quick ECM flashing which lasts maximum of 10 minutes... but the iceberg of the “fraud” scheme is replacing expensive computers instead of organizing normal repair service inside dealership facility.
Thread Starter
Driver School Candidate
Joined: Sep 2014
Posts: 16
Likes: 3
From: FL
try this before you spend any money. Worked for me and others and totally free
https://www.clublexus.com/forums/sc4...t-the-ecu.html
https://www.clublexus.com/forums/sc4...t-the-ecu.html
Thread Starter
Driver School Candidate
Joined: Sep 2014
Posts: 16
Likes: 3
From: FL
Rookie
Joined: Sep 2017
Posts: 80
Likes: 13
From: IL
The ECU is just behind the driver's side headlight. Just a few clips and 10mm bolts and then a few wires. Took me all of 10 minutes with no knowledge of anything under the hood.
Rookie
Joined: Sep 2017
Posts: 80
Likes: 13
From: IL
I sent the unit out on Saturday and had it back by Wednesday. It is the location in Illinois. I am located in Chicago so that might have expedited things, but they still had it sent out same day they received it, so I would say having it back in a week is within reason, regardless of where you are located.
Thread Starter
Driver School Candidate
Joined: Sep 2014
Posts: 16
Likes: 3
From: FL
I was able to take on my ECUand did a visual inspection and it seems fine no leaking capicitors like others mentioned so I’m still hesitant to send it to SIA what if it’s not the computer :/