Vdim

[R1 2003]

Hi, i,m new in this forum.

I´been looking a forum in U.S, because in Spain there are not a lot of Rx400h owners.

I live near the sea, but in winter I use to go to a second house in the Pirinees for ski. Usualy, the road is clean of snow, but to arrive to my house, they don,t clean the street. I saw some videos of the car in snow, and it looks bad.

The question is: Is it possible to dissable the VDIM? How?

Thanks.

(sorry, but my english is very bad)

[williz]

Hi, i,m new in this forum.

I´been looking a forum in U.S, because in Spain there are not a lot of Rx400h owners.

I live near the sea, but in winter I use to go to a second house in the Pirinees for ski. Usualy, the road is clean of snow, but to arrive to my house, they don,t clean the street. I saw some videos of the car in snow, and it looks bad.

The question is: Is it possible to dissable the VDIM? How?

Thanks.

(sorry, but my english is very bad)

hello! nice to here from a RX400 owner in spain.

i live in austria and my house is in the mountains (altitude is about 850m). we have snow here usualy from november till march. so i know what it means to drive the RX400 on snowy and icy roads.

my RX400 is now about 20 month old and has been driven a bit more than 50.000km and i had no difficulty's driving it in wintertime.

there is no way to disable the VDIM.

about a year ago lexus europe promised that from model 2007 on there will be a so called "snow button" but this promise was not kept. but i can tell you there are a lot of RX400's driven in austria and swizerland and i think they all doing well with VDIM active.

actually the VDIM is the best safety electronic system i have seen (and experienced) so far, especially in wintertime.

what you should look for, are very good winter tires. i can recommend the YOKOHAMA AVS Winter dimension 235/55/18.

as this dimension is not very populare start searching for winter tires soon in order to get them before snow fall starts.

for icy roads (and i mean the real one, where you stop the car and it slowly drifts sideways to the pavement) and deep snow, you should get snow chains. there are snow chains available for the RX400 tire dimension which can be mounted/dismounted very easily (in about to minutes and done only from outside of the wheels). if you like i can give you company and type.

let me recommend to you the european LOC's for discussions about the eropean RX400 version (it differs in many ways from the US version) and have fun with your car!

English LOC europe http://www.lexusownersclub.co.uk/forum/index.php?act=idx

german LOC europe

http://euro.lexusownersclub.com/forums/

[R1 2003]

Thanks.

My Rx is about 6 months.

I througt about the winter tires, but I´m afraid that were i live in winter time, the temperature is about 15-20 grades centigrades, and to go to my other house, take 200Km on the motorway and 125 on road, only the last 20 or 30 Km are realy probably on ice or snow, for this i think that perhaps the winter tires will get to used in a few kilometres, for this I think that it was better to disconect de Vdim and use the high performance tires.

I´ll look for the Yokohama tires, but are not a very comercial tires here in Spain. About chains, i have a textil ones.

[williz]

Thanks.

My Rx is about 6 months.

I througt about the winter tires, but I´m afraid that were i live in winter time, the temperature is about 15-20 grades centigrades, and to go to my other house, take 200Km on the motorway and 125 on road, only the last 20 or 30 Km are realy probably on ice or snow, for this i think that perhaps the winter tires will get to used in a few kilometres, for this I think that it was better to disconect de Vdim and use the high performance tires.

I´ll look for the Yokohama tires, but are not a very comercial tires here in Spain. About chains, i have a textil ones.

well, for this kind of usage i would stay on standard (sumer) tires and use "real" snow chains (not the textile ones).

i was driving for 3 month with the standard tires in winter time and we had a lot of snow that year and i had to use the snow chains only once.

some people here use the yokohama winter tires all year round, but for the high temps in spain i would not recommend doing so.

and don't be so concerned about the VDIM it is much better then comparable systems from the competition!

[wwest]

Thanks.

My Rx is about 6 months.

I througt about the winter tires, but I´m afraid that were i live in winter time, the temperature is about 15-20 grades centigrades, and to go to my other house, take 200Km on the motorway and 125 on road, only the last 20 or 30 Km are realy probably on ice or snow, for this i think that perhaps the winter tires will get to used in a few kilometres, for this I think that it was better to disconect de Vdim and use the high performance tires.

I´ll look for the Yokohama tires, but are not a very comercial tires here in Spain. About chains, i have a textil ones.

well, for this kind of usage i would stay on standard (sumer) tires and use "real" snow chains (not the textile ones).

i was driving for 3 month with the standard tires in winter time and we had a lot of snow that year and i had to use the snow chains only once.

some people here use the yokohama winter tires all year round, but for the high temps in spain i would not recommend doing so.

and don't be so concerned about the VDIM it is much better then comparable systems from the competition!

Mine is a 2001 AWD RX300 so much of the following may not work.

For non-hybrid RXes if you unplug the MAF/IAT module connector while the engine is running, idling, the engine will die, plug the module back in, start the engine and drive away with VSC/Trac disabled. For the next few drive cycles you will have a CEL & VSC/Trac diagnostic icon displayed and because the "failure" was intermittent it will extinguish within a few drive cycles. If you wish to restore the VSC/Trac sooner then disconnect the battery or ECU fuse for 30 seconds or so.

VSC/Trac is most DEFINITELY a desired asset for safe driving, period, but especially so on wintertime adverse roadbed conditions. The PSM on the car pictured to the left NEVER gets turned off, but then its AWD system is most definitely REAR TORQUE biased, R/AWD.

There is a wireless relay available in the market if you should wish to do this from the driver's seat. I used one to "open" the GPS/Nav DVD door in the spare tire storage well and thereby disable (no "I agree") the nav system unless/until I want to use it. Rarely, since I now have a portable Garmin which provides STELLAR performance in comparison.

Tire chains, of any type, cannot be used on the rear due to poor tire/suspension clearance. As the RX driver's manual itself states, higher traction on the front wheels vs the rear will often lead to loss of directional control on a slippery roadbed. Think tractor/trailer rig jack-knifing absent drag chains and selective braking on the rearmost wheels of the trailer.

My 2001 AWD RX300 has 1.5" wheel spacers all around, +1 17X8 wheels and is shod with "summer only" Bridgestone Turanza tires. Wider stance, more stability against rollover, more tread on the road, nice and quiet, comfortable ride.

Plus the ability to use tire chains on the rear, SAFELY, FIRST, when the need arises, and add the fronts if required.

I suspect tire chains on only the rear of the RXh might work especially well since that might lead to the VSC/Trac, VDIM, "thinking" the front is slipping and therefore bias the hybrid drive torque toward the rear drive motor. IMMHO in the situations wherein tirechains are to be used it is a good idea, a DAMN good idea, to dedicate the front tires to directional control and the rear tires to "driving" the vehicle forward.

By-the-by, Ford has been awarded a US patent for two techniques involved in making the hybrid Escape and Mariner FRONT WHEEL DRIVE and FRONT torque biased AWD (F/AWD) vehicles much safer in wintertime adverse roadbed conditions. If the OAT declines to near, at, or below freezing the level of regenerative braking, braking that the anti-lock system cannot control, is reduced dramatically. Additionally if actual brake application results in ABS activation the regenerative braking system is INSTANTLY disabled until such time as the brake pedal is released.

I wouldn't be at all surprised to see those SAFETY aspects carried over to the FWD and F/AWD Toyota and Lexus hybrid vehicles very soon.

That probably, might, result in reducing the FE aspects of many hybrid FWD & F/AWD vehicles so low during the winter as to make them useless.

[SOMEONE ELSE'S GOT MY NAME]

Hi, i,m new in this forum.

I´been looking a forum in U.S, because in Spain there are not a lot of Rx400h owners.

I live near the sea, but in winter I use to go to a second house in the Pirinees for ski. Usualy, the road is clean of snow, but to arrive to my house, they don,t clean the street. I saw some videos of the car in snow, and it looks bad.

The question is: Is it possible to dissable the VDIM? How?

Thanks.

(sorry, but my english is very bad)

Hi R1,

Your english grammar is fine. Your concern about traction on the rx-400 (and other Toyota hybrids) has been discussed at length. Most agree that if you get a good set of snow tires, then you are good to go. We keep our 400h in Montana, and though we don't spend winter there all the time, we find that the snow tires do the trick. That's the best recommendation folks will give you. The other - unofficial method is to disconnect the speed sensor modular plugs, but as I've posted before, you didn't hear that from me :P