We might actually be getting somewhere. Sounds like the dealer/service department could potentially have a fix to the issue. Odd that they told BradTank all those years ago to just deal with it. Sadly, Techstream is so expensive, it wouldn’t be feasible to do at home.

 

Because usually a code is thrown if something is out of spec. No codes are being thrown.

 

that’s not how it works with idle learning and many other things. Code only gets thrown when when a value is outside of a operating range.

If you look at the operating range of many idle related parameters, some don’t have a normal range and those that do doesn’t mean it’s optimal as the ECU is designed to accept a wide range of conditions before throwing a code.

Saying that if no code is thrown and therefore nothing wrong is a fallacy. Knowledgable technicians understand and follow strict Lexus troubleshooting procedures to nail out the root cause.

I have done this procedure myself so fully understand the what it does and doesn’t do.

 

There is a popular third party tool that has all the repair and calibration of Techstream. Good review here:

 

Good find. I heard you can also subscribe to Techstream for 2 days or so, for around $65. I'm willing to do that, but need to find out what cable I need to plug my laptop into the OBD2 port. I'm also looking forward to testing the front active mount. I'm sure that should properly suppress most of the vibrations via its computer.

https://techinfo.toyota.com/techInfo..._faq_page#req1

 

Yes that is also a good approach, as you'll also have access to the Service Manual which has step by step instructions on how to reset Learning Idle (look under the Engine -> SFI Section).

Ebay sells many of the TechStream cables and they work fine.

Yes you can also use TechStream to turn the Active Control Engine Mount (ACM) to either On/Off and see if it reduces engine vibration at idle, if it doesn't, then likely the ACM is not working correctly and you can then measure the hose that connects the engine mount insulator for leaks (should be able to hold 80 kPa). ACM is frequency matched to the engine speed via signals from the Engine ECU. It might just be a hose that is not seated properly causing vacuum leaks (rare). So I'd try the Learning Idle first before suspecting the ACM.

One last trick if all else fails is to set the Learning Idle with the A/C on, this will make the car idle higher (poorer fuel consumption), it would be a trade off between vibration at idle or poorer fuel economy.

 

So there's a widespread issue with ES350's having the wrong idle set from the factory? That makes zero sense.

Mine has the same issue, lots of vibration through the steering wheel at a stop and did it when it was still under the warranty. It's clearly something that effects a lot of them and if you're having to raise the idle with TechStream, something is wrong. That's a band-aid fix masking what Lexus did wrong here.

 

It is so hard to believe some dealers didn’t know how to fix it? The issue is not widespread hence no TSB for it. It’s easier for them to say it’s normal.

instead of debating that it’s a design flaw, it’s likely to be either the idle parameters or ACM. The choice is up to you or just accept it.