silver fox

Hi guys, new kid on the block. Thinking about buying a 350. Would like some info.

On the IS 350, is there a procedure to turn off "VDIM, VSC, and TRAC control and have it stay off for the duration of the engine running? I have heard this is possible, but naturally the Lexus dealership will not comment. It would be nice to have the ability to drive the car agressively and not have "big brother" intervene.
Thanks for any feedbback ! ----------From-------- Silver Fox

|mpulse

Nope. VDIM is ALWAYS on, you can disable Traction Control, but once the car hits 30MPH it comes on automatically.

4CYLNDR

yeah its a bit of a problem with the new IS's. IT won't do more than .80 g's around the skidpad because of it, according to Road and Track.

silver fox

I have heard that you can disable VDIM by pressing on the brake pedal a number of times in a row and then do something else (but do not know what) and this should turn off ALL (VDIM, VSC, TRAC ctrl) for the duration of the engine running prior to shutdown. ANYONE ELSE HEAR THIS??--------silver fox--------------------

flipside909

Where did you hear this from? that sounds like a total rumor.

spwolf

take my advice... take IS350 on the drive... drive as fast as you can. And see if you can feel VDIM. I bet you wont, unless you did something really wrong or tried to engage it on purpose.

VDIM is actually a lot less intrussive than previously available ESP system (VSC).

-JD

spwolf, bull, VDIM needs to be off for certain types of drivers, it would totally **** me off. which is why i'm not buying it unless I see a way to disable it.... sorry.

flipside909

spwolf is right...it's not hype. I drove this car through real world conditions before it's official release. If you haven't read my article click on the link on my signature below. Unless you have driven the car to make VDIM engage, you will never know it's there.

TRDFantasy

That described could be a complete rumour, but there is some truth to the whole idea of disabling VDIM.

I'm not sure whether or not you read about the press reveal of the new IS that Lexus Canada had in Toronto a few weeks ago. It was shown at an old airforce base (with plenty of tarmac) and apparently, chief engineer Fukusato was there for a "once in a lifetime display" ... he did some major burnouts in a white IS350 which reportedly had ALL it's electronic nannies (including VDIM) turned off. He did the demonstration to show the power of the new 2GR-FSE engine.

Rumour is that there is a certain way to disable VDIM.

PhilipMSPT

iTrader: (5)

The big problem is that VDIM is not just one entity you can turn off. VDIM consists of numerous safety components such as braking, throttle control, traction, steering assistance, speed sensitive electronic power steering, road condition input, etc.

To turn off the VDIM is to turn off all the interactions of these components (and perhaps to turn off all the components themselves). This is the reason why Lexus engineers state that VDIM cannot be turned off. If they did decide to turn off the VDIM, it would compromise Lexus' standards of safety. Lexus will not compromise safety for aggressive handling.

jeffyee123

I think the code was

UP, UP, DOWN, DOWN, LEFT, RIGHT, LEFT, RIGHT, B, A, B, A

....i kid, i kid...just couldn't resist

KPierson

Taken from the service manual:

System Outline:

1..
2..
3...
4...
5. Fail Safe Function
If an error occurs in the skid control ECU with actuator, sensor signals, and/or actuators, the skid control ECU with actuator inhibits the brake actuator control and inputs the error signal to the engine control module. According to the error signal, the brake actuator turns off the solenoid and the engine control module rejects any electronically controlled throttle open request from the VSC system. As a result, the vehicle functions without the ABS, TRAC, and VSC systems.

So, it looks like, if you fault out the skidpad ECU then all three systems will be gone. According to the service manual there is an ABS2 fuse that goes to the Skidpad ECU. Possibly by removing this fuse you'll be able to enjoy aggressive handling, just remember to put it back in when you are done having your fun.

Unplugging the YAW sensor may have the same effect, someone is just going to have to do some expiramenting.

hofman_dzn

I have also heard this from a Toyota employee who was demo'ing the IS350. He didn't know the details but he did mention a combination of brake pedal applications and trac control switch. I'm waiting for mine so I can test this.

For those that plan on chassis dynoing (2 wheel dyno) the IS, you'll need to disable the VDIM (or at least VSC and TRAC) since the system will think you have wheelspin while you're testing (front wheels stationary while the rears are spinning). You can do this by entering VDIM Test Mode but you'll need the toyota diagnostic tool to do this.

silver fox

Thanks guys, looks we may have something going. My contact was also a Toyata man that told me about the brake pedal, but he also did not have the details. Let's keep it up and maybe someone will know the answer to this.---------------silver fox----------------

|mpulse

Classic Contra.