It seems to be common knowledge, at least in various Lexus GX550 forums, that a lot of people are experiencing rough and clunky transmission shifts. I went back to the dealer after owning the GX for 2 weeks (200 miles) and spoke with the service manager who then had his lead shop foreman take a ride with me. He said the clunking and jerking was normal and would most likely go away because the transmission was in the process of "learning" my driving habits. I have a very light foot on the accelerator and after 1000 miles the shifting is not one bit better now. The clunking and jerking is very noticeable at slower speeds especially going up hills. Does anyone know if Lexus is working on a fix for this issue? Other than the shifting issue I really like the GX550. We also have a GX460 that shifts as smooth as glass which makes the situation even worse.

I appreciate any feedback from others that are experiencing these same issues.

 

As I’ve been researching getting a new GX, I’ve have seen a number of comments on Reddit and FB indicating that Lexus is well aware of the issue and working on a fix (likely a software update). People have also reported that disconnecting the battery for 15-20 minutes helps to “reset” the transmission and the issue goes away…though likely only temporarily.

One last note…it appears that the awareness of this issue at dealerships varies widely. Some are fully aware and openly discuss it; other seemingly have no clue about it suggesting it is “normal” and not an issue.

 

My dealer here in Knoxville TN is of the opinion that the transmission is shifting normally.......WRONG. I have tried disconnecting the battery for 30 minutes and this did nothing to eliminate the problem, in fact, I believe it may be a little worse now. I am hoping by the time I go in for the 6 month service Lexus will issue a TSB to address the problem. Other than this issue I really enjoy the GX, but this is a big black cloud that continues to linger around.

Best of luck with your decision to make a purchase.

 

I’m ready to make the jump…just waiting on my dealership to locate/secure allocation one.

Hopefully a TSB gets released soon…completely understand the frustration.

 

Can anyone who has a dealer that admits a problem, can you provide what was actually done? Flash, reprogram? I'd like to see a copy, so I can take it to my Dealer.

I'm at almost 20K miles. It seems to be slowly getting worse...

 

My suggestion would be to drive the "pixx" out of the car such as jack rabbit starts and hard throttle acceleration at times if possible. Electronic trannies get lazy and sloppy from the easy/light foot syndrome. Drive it like you stole it on occasion and see if it helps.

 

Just to give an update, there is a TSB now, we got it performed on ours. It shifts great.

 

I just checked with my dealer in Melbourne FL and they are not aware of a TSB for this issue. Do you have a TSB number reference we can point to when contacting our dealers?

 

I just had mine done this past Monday. Noticeable difference in the gears. Barely any delay when shifting. Highly recommend having your dealer do it.

FYI* Not many service advisers know about it so I suggest printing out the TSB for them and another copy in the car for the mechanic. I think someone posted it here.

 

sorry, just saw this - its L-SB-0042-25.


Good luck!

 

Is the shift memory just being reset or is the software being updated with the tsb?

 

Software re-flash of ECM;

Flash reprogram the ECM (PCM).

NOTE

 The battery diagnostic tool MUST be used in ECU Reflash Mode to maintain battery voltage at

13.5V while flash reprogramming the vehicle.

 For details on how to use the battery diagnostic tool, refer to the DCA-8000 Instruction Manual

located at TIS – Diagnostics – Tools & Equipment – Battery Diagnostics.

Follow the procedures outlined in Service Bulletin L-SB-0036-22 GTS+ ECU Flash

Reprogramming With Security Signature, and flash the ECM (PCM) with the NEW calibration

file update.

 

true update - not a reset.