Rx400h In Snow- Beware!

[cduluk]

Hey guys. We're having our first real snowstorm tonight here in RI, and i had the pleasure to drive in it earlier (well, not really...).

I started driving when there were about 2-3 inches on the ground, just coming home from my girlfriend's house maybe 10 minutes from mine. On regular roadways, the car handled just fine- actually, surprisingly well. I noticed the skid control or whatever kicked-in on only 2 occasions (as opposed to maybe a million when i had the Rx300) but there was really no need for it. It kept straight and didn't skid out no matter how hard i turned the wheel around corners.

Everything was going smoothly until i was forced to stop short while going up a pretty steep hill because of some stupid Honda that was stuck in front of me- with no lights on!! When the guy finally got out of the way, i hit the gas, but NOTHING. It would "try" for about a foot, then just stop, as if i wasn't hitting the gas at all. It wasn't peeling out, it just wasn't putting any power to the wheels no matter how much or little i pressed the gas. I put the car in Reverse, then tried to go forward again, but it did the same thing!! I tried once more, but no difference- it was determined to not allow power to the wheels. I had to back-up into a driveway (or someone's lawn, i couldn't tell...) and accelerate out and floor it up the hill, to which it handled just fine.

What's the deal with the computer cutting power when on a slope??? I tried it once more when i was in my driveway (which is also a slope) and it did the same thing- just no power to the wheels. It took about 3 or 4 tries before it gave power to the wheels and got me up the hill.

It was a scary thing. The snow was coming down like crazy, i couldn't see anything around me... If there were other cars on the road (besides the Civic that was stuck, poor guy...) it would have been embarrassing and especially dangerous if i couldn't get out of the road.

I'm very upset with the AWD system on the Rx400h in snowy conditions on any type of slope. I understand the computer might not allow power to avoid peeling out, but there should be an override button for situations like this. My Rx300 NEVER handled like this- you'd hit the gas, and you'd go.

My Rx300 was also AWD, and even had a "snow" button that would make the transmission start in low gear for situations just like this. I believe the 400h should have the same!!

One thing about the Rx400h i do like for snowy conditions is the headlight washers. A few sprays and the liquid melts the snow off the headlight lenses and allows some light on the road. It beats having to scrape it off yourself!

Anyone else experience this strange loss of power on slopes with the snow? Thanks guys... :(

[Jim Clark]

I have heard of other people having problems in deep snow even on a flat road or trying to get through a moderate snow bank the plows left. The RX400h AWD system is a joke compared to "real" AWD. My Jeep Grand Cherokee (traded on a Prius in C4C) could go through anything. The Audi wagons we had could also handle nearly anything, especially the allroad with the height adjustable suspension.

[lemon]

Do you have a button to disable the VDIC (vehicle dynamics integrated control - the combination of traction control and skid control) on that year of the 400h? If you do, disabling it may have helped. On my 2006, there is no off switch for the VDIC, so I'm stuck with it.

I have heard that when starting with excessive wheel spin (like in deep snow, ice, or uphill with deep snow/ice like you were in) the system reduces power to stop the wheels from spinning (either reducing engine power or braking the spinning wheel), however, sometimes in deep snow it's best to have a bit of wheel spin to dig through the snow. With VDIC, the common complaint (do a search, others have complained of this as well) is that it reduces power to almost nothing, thereby preventing any forward motion of the vehicle.

Do you have winter tires? That may help as well, as there may be less wheelspin, so the system won't try to stop it by reducing power/braking.

[JimsGX]

This was one of the drawbacks of the 400h that made me decide to get rid of it after a year. I experinced the same thing and thought it was such a joke that the car wouldn't move through a few inches of snow. I had come from a GX470 to the RX400h, so the 4WD/AWD differences were all too apparent for me. Back into aonther GX and I couldn't be happier...

[RX400h]

Based upon previous discussions about the RX400h in snow, the key is having very good snow tires. See the posts listed in the linked post, below:

http://us.lexusownersclub.com/forums/index...8&st=0&

[Jim Clark]

Based upon previous discussions about the RX400h in snow, the key is having very good snow tires. See the posts listed in the linked post, below:

http://us.lexusownersclub.com/forums/index...8&st=0&

With a good AWD system, you should only need good all season tires to handle almost anything. Our Audi wagons with the excellent Quattro AWD system never needed snow tires. Snow tires should only be needed in areas of the great white north where they get LOTS of snow. The best A/S tires for snow are the Continental ContiExtremes. They're also good in regular dry and wet conditions.

[katzjamr]

i think what the 400h is doing on hills is protecting the electric motor from burnout due to excessive wheel spin. my experience is with the 2006 400h, perhaps the new model is improved. going from the goodyears that never should have come with this vehicle to the michelins made a huge difference, i drove for weeks in seattles 08 weeks of snow with no problem

[cduluk]

I've got the Michelin tires on it now which aren't very old. My Rx300 had the all-weather tires on it too, and it handled just fine in the snow.

I'd hate to have to get winter tires for 6 months out of the year just for 2 or 3 snowstorms... Winter tires are LOUD.

I just thought there was a simple solution, like maybe a hidden button or programmable code to trick the computer or something. :(

[RX400h]

Read Consumer Reports' last tire issue and you will likely change your mind about the differences between all-season and winter tires. There really is no comparison. My brother has owned Subarus for many years and he tells me all the time how much better winter tires are when it comes to even light snow. As you know, Subarus are all all-wheel drive. My brother lives in CT, so even though snow is not the norm, snow tires ARE during winter months for a good number of folks who must be on the road during inclement weather.

[JimsGX]

This isn't a tire issue, it's a shortcoming of the vehicle. At times, the RX400h won't let you spin a tire when trying to get out of even a small pile of snow. At least this was the case with my previous 2007... I'd floor the vehicle and it would just sit there. No increase in rpm's, no tire movement.

[cduluk]

Yeah, i know snow tires would probably be an improvement, i just don't think they're worth it (since i don't drive in snow enough).

I'm just trying to figure out if there's anything else (simple) that can be done to fix the car itself rather than the tires...

[RX400h]

Perhaps, this type of tire would be a good compromise:

Michelin Pilot Alpin PA3

Transitioning from the two all-seasons to a dedicated winter tire immediately makes you feel like a better driver in snowy conditions. Placing the G37 becomes a game of inches, rather than of feet, as the Alpin PA3’s ability to turn in is certain and its grip is dependable, leading to a dramatic, 6.3-second lap-time improvement over the MXM4’s. Convincing gains also appeared in acceleration and braking, by 1.5 seconds and 10 feet, which is easily discernible from behind the wheel. But, as mentioned, the PA3 was somewhat surprising, as it did no better than the MXM4 on the snow skidpad. It did deliver on the promise of dry performance, though, pulling 0.87 g on the skidpad and exhibiting a rigid and secure feeling that conceals the fact that it’s a winter tire. Its dry braking roughly split the difference between that of the MXM4 and the X-Ice, whereas wet performance only trailed the MXM4 slightly. The PA3’s stiffer tread enables a 149-mph speed rating, which is second in this group only to the Sport A/S’s 168-mph capability. But does anyone really drive at those sustained speeds? Certainly not on this continent. But the PA3 is an effective middle ground between all-seasons and snow-and-ice tires.

Best For: Traction in the alpine regions for which it’s named while maintaining sports-car responsiveness on dry roads in winter.

Comparable Tires: Bridgestone Blizzak LM-60, Continental ContiWinterContact TS810, Goodyear Eagle Ultra Grip GW-3, Yokohama W.drive

[lemon]

With all the new tire technology, they're not known as 'snow' tires anymore, but 'winter' tires. According to the tire gurus, anytime the temp falls below 7 celsius, all season tires harden, and begin sticking to the road less. Winter tires remain flexible below 7 celsius, thus maintaining more grip to the road. They're not only useful in the snow/ice, but also on the cold pavement.

Regardless, winter tires will help, but it does seem to be a flaw in the design of the vehicle not being able to shut the traction control off.

My last car was a Subaru Outback, well known for a fantastic AWD system, and I also ran winter tires on it. It was truly unstoppable, never having left me stuck. We have yet to get a good dumping of snow here, but I'm hoping I'm not disappointed in the RX, especially after the Subaru AWD system impressed me so much.

[SOMEONE ELSE'S GOT MY NAME]

This isn't a tire issue, it's a shortcoming of the vehicle. At times, the RX400h won't let you spin a tire when trying to get out of even a small pile of snow. At least this was the case with my previous 2007... I'd floor the vehicle and it would just sit there. No increase in rpm's, no tire movement.

Every winter this topic comes up ... and every winter both "sides" come out of the wood work, swinging, "this car is JUNK in the snow/ice" while the other side says, "you don't know what you're talking about, and don't know how to drive in snow" ... which in return gets a, "I've driven ICE in 40 below so YOU don't know what YOU're talking about". So, then both sides quickly degrade. It's quite a POLARizing view (pun intended).

There are excelent workarounds for the hsd safety feature on older hybrids, and the ECU's are set up WAY better on the Gen II RX-450h. We use studded tires from Big O on our AWD 400h, and a temporary disconect for the speed sensor. That workaround meant means we've never had an issue since. Btw, it's NOT the electric motor(s) that potentially face damage from high speed wheel spin, rather the hsd ... so you really have to be carefull if you disconect speed sensors. Here's the irony ... Toyota/Lexus comes up w/ a SUV that'll easily get 26mpg, and for some, all the way up to 30+mpg ... and what ... you think it's going do be the same as a snowcat? (shaking head :P ) sorry ... but just like everything else in life, there ARE tradeoffs.

.

[RX in NC]

As someone who's owned 4WD/AWD vehicles for more than 25 years, the answer is: As previous posters have already told you, get a "real" 4WD/AWD vehicle if you're in deep snow country. The Jeep Grand Cherokee and the Subaru Outback are both great bang-for-the-buck SUVs that can handle any snow conditions thrown at them. My wife has a 2004 RX330 AWD with Bridgestone Alenzas on it, but it can only pretend to be a snow vehicle. Sorry....

[lemon]

True, though having owned an Outback, I wouldn't call it an SUV. Just a very capable station wagon with good ground clearance and a very very good AWD system.

I dunno what all the carping is about. The RX is obviously not an off-road vehicle and I can't believe anyone would mistake it as such. It's basically just a jacked up station wagon as well without the very very good AWD system. It's AWD can help it inclement weather. Not made to do the Rubicon, or plow through 18" of snow.

I haven't experienced the VDIC in any snow as yet, so I'll withhold judgement on that. I do have winter tires, which will hopefully make up for any shortcomings in the AWD system.

[LexRexBlue]

I have an old RX 300 and it does seem to handle better in the snow. However, tires do make a difference and when I had the Michelins on the dealer loaners they weren't great. I have the Alenzas and they work pretty well on the snow/rain etc. and you can use them all year long. They also corner very well. It is hilly where I live and snows, too, but not a New England environment. My only gripe with the 400h is that if it hits a bump it glides over it which you can't control.

[RX400h]

As someone who's owned 4WD/AWD vehicles for more than 25 years, the answer is: As previous posters have already told you, get a "real" 4WD/AWD vehicle if you're in deep snow country. The Jeep Grand Cherokee and the Subaru Outback are both great bang-for-the-buck SUVs that can handle any snow conditions thrown at them. My wife has a 2004 RX330 AWD with Bridgestone Alenzas on it, but it can only pretend to be a snow vehicle. Sorry....

Unfortunately, few people who have owned one of the most reliable vehicles on the planet would buy one of the least reliable vehicles (any Jeep), whether it be good in the snow or not. At least Subarus are average or better when it comes to reliability. Mercedes has a diesel SUV, but it exhibited many problems, including no-starts as a Car & Driver long-term test vehicle. In any other case, fuel mileage suffers quite a bit when comparing non-hybrid SUVs with very good off-road/snow capabilities.

[JimsGX]

It may not be saying much for the RX line, but the RX350 is much more capable in snow than the 400h. I didn't realize when I purchased my RX400h that it would be so limited in its AWD abilities. I wasn't expecting it to be like my GX470, I know they're very different animals, but I made an assumption that it would be comparable to the RX350. I didn't have an opportunity to test its AWD capabilities prior to purchase. Hopefully Lexus is working on addressing the problems with the vehicle in this area. In the interim, maybe they should add an AWD disclaimer to the NAV screen at startup and make us all hit the "I Agree" button like we all had to do through MY2007!

[cduluk]

Yeah, the Rx300 was awesome in the snow. I've never owned a Subaru or Jeep, but for what i needed it for, the Rx300 handled snowy weather just fine.

The Rx400h is fine also until the computer shuts power to the wheels on a slope. It would be fine if i could just bypass the computer. It's not a tire issue, it's a computer issue. After a few tries, i did seem to trick the computer and the 400h went up the hill like nobody's business!

What exactly needs to be done to the speed sensor to get it to work? It's gotta be something more complicated than that...

[RX400h]

But it IS a tire issue as well. A true snow tire won't slip nearly as easily as an all-season tire. Once your tire(s) slip, power is drastically reduced to the drive wheels and you go nowhere.

[RX in NC]

RX400h,

Ever owned a Jeep yourself? We've had 5 of them in our family since 1985. None of them came close to being the problem child that my wife's previous 2000 RX300 AWD was (by far the worst vehicle I've owned in more than 40 years of driving). Keep those Jeeps maintained and you'll be enjoying them for more than 100,000 miles as we did with every one of ours....

[cduluk]

So you're saying if i put winter tires on the Rx400h (with better grip) the wheels won't slip as much, therefore the computer won't feel the need to stop power to the wheels?

... AKA the computer only stops power when it senses slipping?

I guess that makes sense, but i still think there's gotta be a better solution. Is there ANY secret programming feature or some other way to trick the computer in times like this?

Can i run some wiring that would allow me to press a button that would break the circuit for the skid control or something? Is there a fuse that controls this "computer" issue that i could unplug when i really need power up a hill?

What's the actual "system" that stops power to the wheels when it detects slippage? Is it "VSC" (or 400h equivalent), is it the speed sensor?

I mean, if i can run a toggle switch to turn this "system" off for a few minutes when i really need it... that seems like a good idea to me. I just don't know which system actually controls this. <_<

[RX400h]

RX400h,

Ever owned a Jeep yourself? We've had 5 of them in our family since 1985. None of them came close to being the problem child that my wife's previous 2000 RX300 AWD was (by far the worst vehicle I've owned in more than 40 years of driving). Keep those Jeeps maintained and you'll be enjoying them for more than 100,000 miles as we did with every one of ours....

I guess it's the horrible reliability ratings from Consumer Reports (much worse than average for all years from 98-05, except 03 and 04s which were just average) as well as friends and family who did own Jeeps that have kept me from even going near that vehicle. Chrysler is at the bottom of the barrel when it comes to reliability of its vehicles - this has been published extensively. Believe it or not, I have known many people who love Corvettes and insist that they are reliable vehicles. However, one look at CR's Auto report and many years of personal experience have proved to me that this is just not true.

On the other hand, we are approaching 5 years of ownership of our RX400h and it has not had one problem. This is beyond amazing, but while it is possible that this is an isolated case, ask folks on this forum who have owned an RX400h for over 4 years; I'm certain they have had similar experiences. CR's auto issue bears this out as well.

So you're saying if i put winter tires on the Rx400h (with better grip) the wheels won't slip as much, therefore the computer won't feel the need to stop power to the wheels?

... AKA the computer only stops power when it senses slipping?

Based upon others experiences (here on this forum), that appears to be the case. Whether having the extra traction is worth the cost and effort all depends upon where you live and how critical it is for you to drive in the snow on hilly terrain. To my brother in CT, having a set of snow tires is well worth it.

Dave

[cduluk]

I think that's the biggest question... For myself, i don't think it would be worth installing winter tires and having to hear the extra road noise, just to "possibly" help the Rx400h get me up a hill the once or twice a year i have to drive in it :o

Even if i did have snow tires, it still wouldn't be eliminating the actual problem being that the car cuts power to the wheels if it detects any slippage...

There's gotta be a shortcut to solve the root of the problem rather than the symptoms...