Toyota Sienna 2004+

stickguy

saw a nice AWD XLE limited at the dealer the other day. MSRP only ~38.5K. Ouch.

Of note, they sold the one van they were keeping as a demo, so now they have nothing that you can drive. If you are lucky, there will be a sold unit you can sit in (not start though).

At least the Chrysler dealer next door must be happy, since he probably gets some business from people that actually need a car not, not eventually. And, how will you know if you like it if you can't drive it?

Wonder how long before the supply somewhat catches up. Maybe in the mid winter period, when no one feels like car shopping in the NE.

javadoc

M'kay... only about 90days left on the countdown till I get to visit the City of Roses and pick up my Ltd AWD...

That is, if there's not some kind of delay...but the features are worth the wait.

stever

Especially that AWD, which you might be wishing for come morning, eh Java? Snow by Halloween sounds about right for Anchorage :-)

Steve, Host

javadoc

I had snow on my T5 today when I woke up... about 1/2 inch... but it had melted by noon (whew!). The car stayed parked, and if you saw my Yokohama AVSs, you'd understand why. The phrase 'racing slicks' come to mind. I've already hauled both sets of Hakkas out of the shed, and have the air and torque wrenches all lined up in case winter truly arrives in the next few days. If it can hold off for another 12 days, that'd be great.. b/c I'll be on a beach by then. But, the forcast on wunderground doth speak towards things being white.

Even better than snow, I tried to get pictures of this enormous bull moose eating my neighbor's most-prized bushes, but he only showed me his back side. I dared not cross the street for a better angle.

But yes (content), I'm look forward to a number of features this winter on the Sienna.

lekn

I agree with Steve. But for the sake of new readers, I want to clear up any confusions caused by wwest's wrong facts when he wrote:

> AWD with front torque biasing, Highlander, RX300, MDX, Sienna

The only AWD Sienna produced has 50/50 torque split on normal driving according to official Toyota specs; saying it otherwise is irresponsible.

Equating Sienna with MDX which has 100/0 torque split on normal driving is absurd.

wwest

If anyone, and I do mean anyone, can explain the effect of differing final drive ratios front and rear on the sienna, I'll gladly buy into the 50/50 torque split idea.

kmead

Dear Mr West:

From the "Sienna New Features Guide" from the New Car Features section at techinfo.toyota.com:

"4WD SYSTEM
 DESCRIPTION
  The 4WD model of the ’04 Sienna has adopted a
full-time 4WD system that constantly distributes
torque at a ratio of 50:50 to the front and rear axles."

Both final drives have 14 pinion teeth and 41 ring gear teeth for a overall reduction of 2.92

So, now you have proof of the manner in which the system can and does transfer torque equally. So kindly lay off.

Further more, your thinking is very flawed on the entire issue of FWD handling in poor weather. You continue to mislead people with poor advice that is in fact erroneous. As you do not have a Sienna, any other minivan or any intention of owning one, it would be nice if you stayed away form these forums.

Kindly haunt the Porsche and RX300 forums and speak with people that share your interests. We do not, and would prefer not to see you spouting such unadulterated BS in this forum.

Good day and good bye to you sir.

momstruck1

I am a little worried as most of you know i have had a bad experience with my last two gm's and we are really looking into the sienna for the 2005 year . we looked at the 2004'S and have to say it is the nicest mini-van out there . We are now choosing between the XLE and the limited XLE i think the limited is a little out of my price range and we will go with the XLE . Can anyone really say that the limited is really worth the extra money since it is basically the same van with the very few extra's that i really need. i really want the package with the dvd player . can anyone give us some advice on how toyota's run over all and if you have a toyota has there been all kinds of little problems where you are alwys back at the dealership?

wwest

I do own a 92 Aerostar, AWD, rear bias, 30/70 F/R, except with slippage, 50/50. I have also owned a 98, 99, and 00, AWD T&C. Daughter still owns the 00, I drove it just yesterday.

I suppose you would call the Aerostar a Midi-van, but the papers always list it an Mini.

I'll certainly have a look at the Toyota tech site, but Lexus (Toyota) has told me, in writing, that the Sienna and the RX330 share a common drive train, and that the RX330 has a front final drive ratio of ~3.48 front and 2.92 rear.

But then Lexus also advertises the RX330 as having a 50/50 torque split.

mdell2

It was the safety features (VSC, TRAC, rear disc break, side curtain airbag) that attracted me to the 04 Seinna. However, after some search and rethinking I ordered a LE without any of these features. But now, I am not sure if I have made a correct decision. Please help.

Here are the reasons that I decide not to have these features, if I am wrong, correct me:

VSC—It will not engage if you are applying the breaks. For most people, when side skid occur, they will follow their instinct and try to reduce the speed by breaking. My second concern is that if you try to merge into traffics at an intersection, you accelerate while turning, the van skids and VSC engages, (I am not sure if VSC also cut power) this may prevent you accelerate, and may cause accident.

TRAC—It is not that helpful in a FWD. You may have a difficult time rocking and spining out of snow bank in winter.

Rear disc break—It is a tall FWD van. When breaking there is a significant forward shifting of weigh, and the front disc break have to do the majority of the work. The rear pads in my Maxima last 110,000miles.

Side curtain airbag—In severe side impacts, curtain airbag increase the odd of survival. But the detonation of the airbag caused by moderate impact can cause lethal injuries too. This is particularly dangerous for older people (they has a shrunk brain (due to aging) with bridging veins attached to their skull, this makes they vulnerable for brain hemorrhage). The sales person told me that the curtain airbags in Sienna are not installed in the roof or doors. They come from the pillar between the first and second row, and shoot all the way to the far back. Therefore, you must keep away from the windows. But in side impact, it is impossible that the passenger does not move toward the window (or the window moves toward the passenger), it is the law of physics.

lok888

comes with VSC, TRAC, rear disc brakes, 3 rows side airbags, 16" alloy wheels, windshield de-icer, plus few more items. You won't find any of these on a regular LE FWD. It is an option.

cxc27

Does anyone know if the Nav system in the new Sienna has a transmitter as well as a receiver. I understand the receiver would be to accept signals from the satellite to find out your location. I guess I just would not want the system to also be transmitting information as to my location. Not afraid of big brother, but worried that the signal could cause some sort of cancer or something over time. Does anyone know?

dplachta

mdell2-

I went thru the same process and reached the same conclusion as you did regarding VCS/TRAC. I perhaps would have gotten those features if the packaging didn't require considerable more expense.

My thinking was that whenever I've lost control of a vehicle (which happens from time to time as it snows 50+ inches a year here) I am either braking or, upon noticing the problem, will then apply the brakes. Once I hit the brakes, VCS and TRAC are not important. Most of the time I've noticed a loss of control when braking, not while accelerating or driving (I would guess 85% of the time). On the relatively rare occasions that I'm not braking and notice a fishtail or skid, I believe that braking helps a lot and the brake system that the Sienna has should reduce or eliminate the control problem fairly quickly. It might, however, not control it in time and it is possible that the VCS and TRAC would have prevented the incident from occurring in the first place. The question you have to answer is that risk I described acceptable or not? Is it worth it to spend $2.9K (to get option package #7) reduce that risk?

Then ask yourself, did you feel unsafe in your last vehicle, which also did not have those features?

This is a very personal decision, and I think it is quite difficult. We got option package 1 (AM and FE) and saved $2300 over package 7. I feel safe, but only time will tell if I made a wise decision. I've questioned myself on this, too.

cxc27

Does anyone know if the Nav system in the new Sienna has a transmitter as well as a receiver. I understand the receiver would be to accept signals from the satellite to find out your location. I guess I just would not want the system to also be transmitting information as to my location. Not afraid of big brother, but worried that the signal could cause some sort of cancer or something over time. Does anyone know?

wwest

IMMHO these features, VSC, Trac, etc, are very desirable in a FWD (ANY vehicle, but FWD moreso, my 01 C4 has PSM) vehicle since Trac will oftentimes prevent the front wheels from losing traction with the roadbed, and believe me, you NEED those wheels to maintain traction with the roadbed if you expect to maintain directional control of the vehicle.

Earlier implementations of Trac, 92 LS, did have the bad habit of dethrottling the engine (along with rear braking) for too long a period after the "event" but I believe that design flaw has long since been overcome.

The VSC system seems to be somewhat benign in that it doesn't seem to activate unless you screw up badly.

dako_tian

I agree with your decision and most of your reasoning and with mdell2's as well (though living in the Dallas area make VSC and TRAC nearly useless to me anyway). Still, I must take issue with your criteria of how safe you "feel" as a rational decision-making tool.

I don't mean to be picky, but the entire country's "feeling" of safety was shaken badly a couple years back, for good reason. Our "feeling" of invincibility was proven ill-advised. Even so, the actual risk for any one individual has most likely increased only negligibly.

Feelings are simply subjective, easily-influenced by too many factors, and a confident feeling is prone to increase as our personal experience yields no problems.

This helps explain the widespread tendency to "push" a red light: no accident occurred to date in doing so, so I'll gain more confidence in repeating this behavior. Obviously, the "bad experience" that proves how bad this logic really is might well be fatal. In such cases, "learning" is irrelevant --- at least to the no-longer-functioning occupants of the vehicle(s) involved.

Also note that "feelings" are undoubtedly responsible for the unmitigated success of lotteries (definition: a tax on people who are poor at math). Go figure (and if you really do figure, then you won't participate in lotteries! ;-)).

So, I propose that "feeling" safe is about as useful for decision-making as ignorance. Better to look for more objective criteria. I would suggest the IIHS tests and conclusions. They have a high level of self-interest (reducing Insurance settlements) in judging what is safest. These, of course, must be interpreted (as you both have) wrt your own driving circumstances.

dplachta

might not be what I should have said. I'd rather say that I don't feel unsafe. My biggest safety issue is human error, mostly concerning others but also my wife and myself. Other safety issues I have are black ice and fog, which rarely occur.

I know the safety ratings for this van are good, which helps support my comment. I also know that the last generation Sienna had good ratings, so I believe further testing will also show this van scores well.

dako_tian

And those facts, plus the availability of 8 seats, were the things that got my wife past an initial strong distaste for the new Sienna's looks. I was less negative to start with, but the new look is growing on both of us as time passes.

Of course, that's another subjective feeling that probably weighs more in our decisions than many of us, supposedly practical family folks, will readily admit! OK, OK, I admit it. But it's the fault of those durned Jones' living next door! ;-)

dplachta

I put a deposit down on this vehicle in January, without even knowing what it looked like.

I figured it would look pretty good, but was concerned it might resemble the Avalon, which I don't like. We had heard about its size and engine, and split back rear seats.

I'm very pleased with it. I love the Salsa Red, and love the interior.

mdell2

Fear is the most powerful influence in one’s behavior. When we are too focused on the fear, we may fail to see the reality. I think the most import safety factors are ranked as following:

1. Seat belt
2. The crash worthiness
3. Vehicle weight
4. Front airbags
5. ABS
6. Seat height
7. Tires
8. Break
9. Handling
10. Reliability (of the above features)

Considering these features, 04 Sienna are safer than most of the vehicles on the road.

vaeagles1

IN REAL-WORLD CRASHES, SIDE AIRBAGS
WITH HEAD PROTECTION ARE SAVING LIVES

ARLINGTON, VA -- Side airbags that include head protection are reducing deaths by about 45 percent among drivers of passenger cars struck on the near (driver) side. Side airbags that protect the chest and abdomen, but not the head, also are reducing deaths, but they're less effective (about 10 percent). These are the major findings of an Insurance Institute for Highway Safety study of the real-world effectiveness of side airbags. It's the first such study to estimate the effectiveness of this type of occupant protection.

Dateline: August 26, 2003

http://www.hwysafety.org/news_releases/2003/pr082603.htm

Also, by the 2003 model year, 40 percent of all passenger vehicle models offered head-protecting side airbags (24 percent standard equipment, 16 percent optional equipment; see attachment for list of 2004 model passenger vehicles equipped with side airbags).

Soon, all vehicles will have side curtain bags. It is only a matter of time.

wwest

1. Driver.
2. Driver.
3. Driver.
4.......

kmead

Sadly, many of you made your decisions on very poor information.

Stability control works whether you are braking or not. It will use the brakes to assist in regaining control, but it does not mean that if you are braking it will not work.

Stability control can be useful in all weather and road conditions. The system compares the motions of the vehicle compared to the inputs by the driver. If they are not in tandem such as steering into a skid, it intervenes by applying brakes on individual wheels to regain control. The following is from Toyota's tech site:
5. Outline of VSC System
General
The followings are two examples that can be considered as circumstances in which the tires exceed their lateral grip limit.
The VSC system is designed to help control the vehicle behavior by controlling the engine output and the brakes at each wheel when the vehicle is under one of the conditions indicated below.
  When the front wheels lose grip in relation to the rear wheels (strong front wheel skid tendency).
  When the rear wheels lose grip in relation to the front wheels (strong rear wheel skid tendency).
Strong Front Wheel Skid Tendency Strong Rear Wheel Skid Tendency
Method for Determining the Vehicle Condition
To determine the condition of the vehicle, sensors detect the steering angle, vehicle speed, vehicle’s yaw
rate, and the vehicle’s lateral acceleration, which are then calculated by the skid control ECU.
1) Determining Front Wheel Skid
Whether or not the vehicle is in the state of front wheel skid is determined by the difference between the target yaw rate and the vehicle’s actual yaw rate. When the vehicle’s actual yaw rate is smaller than the yaw rate (a target yaw rate that is determined by the vehicle speed and steering angle) that should be rightfully generated when the driver operates the steering wheel, it means the vehicle is making a turn at a greater angle than the locus of travel. Thus, the skid control ECU determines that there is a large tendency to front wheel skid.
 2) Determining Rear Wheel Skid
Whether or not the vehicle is in the state of rear wheel skid is determined by the values of the vehicle’s slip angle and the vehicle’s slip angular velocity (time-dependent changes in the vehicle’s slip angle). When the vehicle’s slip angle is large, and the slip angular velocity is also large, the skid control ECU determines that the vehicle has a large rear wheel skid tendency.
Method for VSC Operation
When the skid control ECU determines that the vehicle exhibits a tendency to front wheel skid or rear skid, it decreases the engine output by throttle control and applies the brake of a front or rear wheel to control the vehicle’s yaw moment.
The basic operation of the VSC is described below. However, the control method differs depending vehicle’s characteristics and driving conditions.
1) Dampening a Strong Front Wheel Skid
When the skid control ECU determines that there is a large front wheel skid tendency, it counteracts in accordance with the extent of that tendency. The skid control ECU controls the engine power output and applies the brakes of the front wheels and rear wheel of the inner circle of the turn in order to restrain the front wheel skid tendency.
2) Dampening a Strong Rear Wheel Skid
When the skid control ECU determines that there is a large rear wheel skid tendency, it counteracts in accordance with the extent of that tendency. It applies the brakes of the front wheel of the outer circle of the turn, and generates an outward moment of inertia in the vehicle, in order to restrain the rear wheel skid tendency. Along with the reduction in the vehicle speed caused by the braking force, the vehicle’s stability is further improved.
In some cases, the skid control ECU applies the brake of the rear wheels, as necessary.

In regards to the side curtain airbags, the salesman was not correct in telling you the location of the side curtain airbag system. The bags are located in an arc that extends from the front actuator at the base of the A pillar to the top of the rear most pillar where the rear actuator is located. They inflate downward all the way along the window line from the top. Without question you should make every effort to not be directly in the path of any airbag as they can and will injure you.

I ordered my Sienna with package 7. We have never owned such a large vehicle (both size and wieght) and having every opportunity to keep it in control is worthwhile. I also think that a paltry 2000 over the decade I own it is relatively cheap insurance. I will only have one wife and children like the ones I have now.

I have to agree with Mr West on several statements here, the stability and traction control can benefit anyone regardless of the location they live in. Safety is a state of mind and an attitude. Above and beyond the quality and features of these machines, it does come down to the driver, first last and always in operating their vehicle safely.

user777

whew..that VSC is interesting automation.

can someone tell me if this VSC could in anyway be a contributor to the observations in the 2004+ problems posts #s 179, 180, 189, and 190?

there seem to be some people reporting loss of power when cornering and applying the gas.

a slipping transmission is one thing - but what you provided is a description of an authority for over-riding the driver's inputs based on a pre-programmed operational envelope of some sort.

i wonder if there's possible overlap in the scenarios / envelopes?

kmead

I have read about the hesitation from a number of people here. I have not seen it spoken of at another forum about the Sienna I frequent.

I don't think the TRAC or VSC are at fault as they are unlikely to be sensing any conditions that would cause them to try to intervene. A turn to the right with the wheel turned in that direction would be perfectly normal and not out of bounds for example, thus no issue.

I don't know that the following is the answer or not, but given what I know about cars and the way Toyota seems to approach issues I think it is this:

 When you take your foot off the gas for a corner or other slowdown, the transmission stays in the gear it was in to minimize engine braking and maximize fuel economy. As you ease into the gas upon exiting the corner, you likely don't floor it as that is not the amount of power you expect to need. However the ECU still has the tranny in 4 or 5, you are going slow enough that you really are expecting a lower gear to accelerate out. The ECU finally ascertains that you need more acceleration than can be delivered in that gear so it shifts down. This all takes time, the delay that many are experiencing.

Out of curiousity, does the rev counter show a low rpm that then jumps up as the car actually responds? If it does it would tend to confirm my theory.

Here are a few things to try:

Get all your braking done before the corner. Then lightly accelerate as you enter and go around the corner, increasing your speed as you exit the corner. Is the power delivery more consistent and immediate?

Try using that nifty shift lever to manually shift down to the gear you need for the exit of the corner when you are mid turn. This will take some coordination but modern trannys will not shift into a dangerous/damaging gear until the speeds and engine speed are in the right range for each other. Just try to 'force' the shift before you actually need the increased acceleration.

Having only driven manual transmission cars all my life and only an automatic when renting, I find all automatics to be in the wrong gear and hesitate all the time. I have yet to have one be programmed to provide the power I desire when I desire it.

Keep in mind this vehicle is large, has a fair amount of torque (not a lot) and is tuned for economy. It will never behave like a sedan, as much as they try to make them seem that way.

user777

thanks.

the experiment should be conducted on the straight don't you think? if the behavior is the same (delay while the ECU/tranny determine proper gearing), maybe you're right.

if not ???

kmead

Yes, you should try it on a straight first, slowing to the same speed you would to go around a corner and then accelerating in the same way you would.

Regardless of the outcome, the same thing should be tried on a corner regardless of the outcome of the first test as it may behave differently in both circumstances.

Having thought a bit more about this, if there was sand or other material on the pavement, it could cause the traction control to retard the engine output. The other possibility is that the driver applies full throttle and the traction control senses incipient wheel spin and retards engine output.

I haven't taken the time to go back and look at the various vehicles equipment which are being effected by this problem. If there is a commonality it would be easier to isolate the problem.

dplachta

That write-up you provided shows how VCS works to prevent loss of control. It looks like an important development in vehicle safety.

However, I did not read there how it works when you apply brakes. I don't believe it does.

When you brake, the ABS with electronic brake distribution (EBD) system kicks in to control the vehicle.

dako_tian

Thanks for the detailed post from Toyota's tech site. It is one of the few of such length that I thought worth wading through. I found the descriptions most convincing.

But, since I only vaguely remember my 3 semesters of majors Physics and the math challenges therein, I trust this explanation in much the same way I trusted most of the documents I've signed when closing on a house (or in buying anything on credit, for that matter). I do so without true understanding (in addition to not being a physicist, I am also not a lawyer), but hoping and praying that someone else would have exposed any deception long before I got there.

It comes down to doing my best to deal with reputable companies (whether real estate agents, title companies, insurance industry test groups, or automobile manufacturers) and trusting in the only One who can be counted on to care about me in any circumstances.

I appreciate the facts you presented; it is always nice to think there is good reasoning behind it all. But, some sort of faith is always involved. And, it seems to me, of all the automobile makers around, Toyota is one I would put at or near the top on my trustworthiness scale (their dealerships not necessarily included).

dplachta

I'd like to add one other comment regarding this issue of buying the VCS and TRAC package 7 for the 2004 Sienna.

Be cautious in your advice.

To advise someone to spend the $2900 for such a system is something you cannot justify for them.

At the same time, it is irresponsible to advise folks to not buy this system, as it does improve the safety of the vehicle.

Just because you bought this or didn't buy this does not make you correct.

petl

We may never be able to prove it, but having them may have saved some lives or prevented some accidents. Maybe the casualty list would be higher without them. Like I said before, there will always be stupid, inattentive drivers. If catches just one driver's eye, it's good enough for me. I would still prefer to "hopefully" be seen with DRL's than to drive without them. Please read my previous post. We should all be driving tanks, I guess.

wwest

If I read that correctly it says that during understeering it applies brakes to both front wheels and the inside circle rear wheel. I'm quite certain that is wrong.

Understeering is the result of not having sufficient traction at the front to overcome momentum and "force" the vehicle to follow the angle of the front wheels.

Braking at the front in this circumstance would most certainly exacerbate the problem, whereas braking BOTH rear wheels in this circumstance would help to slow the vehicle, especially FWD, helping to regain traction.

And that is the method used on my RX300 in this circumstance.

wwest

It is my understanding that some forms of VSC, if not VSC itsself, will slightly release "opposite" brakes during braking to accommodate the corrective need.

BMW now has a system that will counter-steer, (yes, that's right, modify/reduce your steering inputs!)out of a turn, if the system deems it necessary.

So I find it very easy to believe Toyota would prevent transmission downshifts and simultaneous WOT with high yaw sensor conditions.

But the minute Toyota/Lexus introduces counter-steering I'll stop buying new vehicles and go into vehicle restoration.

I still think a "stick shaker" is the best solution.

wishisaccptd

Can anyone share with me about the DVD installed by Toyota?
The brand, the monitor size, personal opinion, etc...
I'm closed to purchase an XLE with pkg #15 (DVD, 17 inch wheels,...) but haven't seen one with DVD yet!

jake696

Wouldn't you rather hear how many angels can dance on the head of a pin? Or how engineer wanna-bees like to listen to themselves talk? (write) The DVD itself has no markings other than Toyota's and JBL Synthesis (the speaker system).

kmead

First the traction control and stability control do not cost 2900. They are in combination with a variety of other options, which include power doors, rear entertainment, alloys, homelink and most importantly side curtain and side airbags.

The traction control and VSC add about 350 to the package that doesn't include it with alloys being the remainder of the difference. Should it maybe cost less, as Toyota seems bent on profiteering on safety features? Sure.

Compared to spending 1300 for a DVD player or 800 for an upgraded stereo, paying a bit for safety features is not a big deal in my view.

Although I think those who did not buy side curtain airbags etc made a poor decision, I did not say so (at least not lately). I did want to point out the poor information the decision was based on. Not understanding the mechanics of the system, which I have not done a good job of explaining apparently, and relying on a salesman who clearly did not read the information Toyota provided, is no way to make a decision.

The TRAC and VSC can control individual brakes, even while you are using the brakes, these two things do not cancel each other out (you versus the system). Mr West's lack of understanding of how the systems work and his very flawed ideas about braking the rear wheels do little to help. These plus the EBD and brake assist are all part of one system that are the controls for ABS. Its just a higher level chip and appropriate programming ()lots of that) as the parts have been in place for these systems for 20 years, just microprocessors have not been around that were fast and cheap enough to put into a vehicle.

Braking the rear wheels which have considerably less wieght and traction can and will have negative effects. Braking the inside rear wheel will tend to slew the vehicle in that direction, whereas braking both rear wheels would tend to exacerbate the issue by unloading the front wheels, possibly causing a spin. The front wheels are braked to increase front wieght transfer (to the front) which increases the traction available there. In most terminal understeer cases the front wheels are being buzzed (spinning because of excessive throttle) so slowing the wheels will tend to reestablish traction. If you are under braking already it adds the additional braking to the inside rear wheel and reduces braking to the outside rear wheel. This is explained here in another part of the same document I have quoted:

"2) Front Wheel Skid Control (Turn to the Right)
In the front wheel skid control, the brakes of the front wheels and the rear wheel of the inner circle of the turn are applied.
Also, depending on whether the brake is ON or OFF and the condition of the vehicle, there are circumstances in which the brake might not be applied to the wheels even if those wheels are targeted for braking.
The diagram below (not pasteable here) shows the hydraulic circuit in the pressure increase mode, as it controls the front wheel skid condition while the vehicle makes a right turn.
The pressure holding valve and the pressure reduction valve are turned ON/OFF according to the ABS operation pattern."

The manner in which the system is explained is simplified and leaves out the issue of time, meaning that the system does all this very quickly and not for an extended period. It also likely will stop applying the front brakes first as it is trying to keep the wheels rolling, as rolling wheels have much more traction than stopped wheels. It may even find it has been overly aggressive in it approach and has to correct in the opposite fashion (for a rear wheel skid or spin) before the vehicle stabilizes.

The system has a shut off button that allows you to perform the 'rock the vehicle out of a snowdrift' manuever.

Toyota's VSC system has a reputation for being overly cautious, by which I mean that it tends to react vigorously to minor intransgretions.

In any case, none of these systems can perform miracles, eventually the vehicle will be outside the possible performance envelope and cannot be brought back under control. In this case it comes back to Mr West's earlier and very correct point: it is the driver, the driver the driver. I hope I never have the system need to act, but if it does and it allows me to avoid or minimize an accident it will be well worth the investment.

So, if you didn't buy these options, fine, its your life, if you did thats fine too. I just know that I am buying them as I would like my wife (the primary driver) to have every chance to keep from having an accident and surviving as well as possible if it can't be avoided actively.

dlandthr

Hi, I just bought a Sienna XLE. I went back and forth for a week between two dealerships. One had a van coming in that he was going to add the all-in-one DVD entertainment system to for me as soon as it got to port by Toyota--I'm assuming it would be the same as what would have been installed at factory. The other one had a van on the lot that was prewired for DVD and he assured me it would be the same system. When I picked up, I was excited to hear he had given us a DVD/TV set. However, it didn't look like the standard Toyota set. It took me a few days to realize we no longer had the standard rear seat audio system. They took out the system to install the DVD. So the kids can only listen to the DVD or CD (played on the DVD) through the headphones and cannot control the radio or tape player at all. Has anyone else had a DVD added after the van was in the lot and been able to keep the rear seat audio? I am very upset and feel I was lied to. Now they say all they can do is put the rear audio console back up, so we'll have two consoles on the ceiling to bump our heads on. Otherwise, I love everything about the van. I feel like I'm complaining over a little thing, but the rear audio is part of the reason we picked XLE over LE. We didn't get any option package.

mdell2

I was planning to buy a Sequoia, so I follow that forum for a while. I noticed some owners were furious about their oversensitive VSC which cut the vehicles’ power at intersections and leave them in the dangerous situation. Finally they reached a practical solution: to engage 4WD all the time, or turn off VSC in the RWD version if such a situation is anticipated. OUCH!

Also in that forum, an experienced Toyota sale person told a story: A Landcrusier owner drift out the road in a curve and landed in a ditch, he asked him why, and he said that he shoundn’t use the break.

All are real life experiences, it doesn’t matter how good it is in paper or in theory. This is how I lost my confidence in Sequoia. I really hope Toyota learned from it, and improved the VSC on Sienna. So far nobody complained about it on Sienna, it is a very positive sign.

Like the front airbag, it takes time for us to know the safe use of a new technology. Let these great experiments carry on, it will benifit everyone.

user777

the [problem]from my perspective - if the technology usurps the authority of the driver and becomes a contributing factor, either because the driver didn't understand the technology and what it was doing for him or her, or the technology wasn't programmed to assist properly in the given scenario.

call me old school: being in my first vehicle with an automatic transmission (somebody else's programmed profile for better mileage...hmmm - my only prior exposure was while renting on travel) and ABS ("stomp and steer"), there's some new tricks for this dog to learn.

...now this VSC...

this is going to sound nutty...i actually feel more confident in my ability to control my 5spd manual...

kmead

I know exactly what you are saying. I own 3 cars from the early seventies/late sixties, with none of the modern conveniences. As a driver you are in control.

The new systems are very capable and faster at reacting than either of us could ever hope to be. They have been heavily tested and in production for quite a while now. This is one of those situations where trickle down actually works, as these chips have been used in Lexus vehicles for quite some time.

It does take some getting used to, and it certainly may not be for everybody, but it can have a very big effect on your safety. I looked around for some other info which can be found at the following links:

http://www.esccoalition.com/

http://www.cbsnews.com/stories/2003/07/21/tech/main564126.shtml

http://www.usatoday.com/money/autos/2003-08-06-rollover_x.htm

http://www.montanaforum.com/rednews/2003/07/21/build/safety/vehic- le-control.php?nnn=3

http://www.edmunds.com/ownership/safety/articles/45992/article.ht- ml

http://www.mucda.mb.ca/Stability.htm

There are others, but if anyone is more interested, I suspect you could find them on your own. Have a good day.

kmead

I find this very second hand information from sales people very suspect.

If power was cut in the middle of an intersection, they were trying to do something in all likelyhood they shouldn't have for the conditions that existed. Meaning, trying to accelerate too fast because they chose to go across an intersection when there was poor traction and not enough time before the next vehicle was going to pass through the intersection.

As for any SUV ending up in the ditch, they all too often go too fast for the conditions and end up in trouble because they are operating outside the traction envelope for the manuever they are trying to execute. Just because you can get up to 60 doesn't mean you can safely operate at that speed. I see more SUVs in ditches and upside down than any other vehicle type. They are heavy and once driven in a particular direction, changing that direction can be problematic. On a low traction surface the amount of inertia that needs to be overcome to stop or change direction works against them especially if they are already travelling too fast for conditions.

dplachta

Your collection of info is great and you are providing much value to this discussion. Information helps the individual make this cost/risk decision.

Two things. The cost of option package 7 is $2900. Sure you get other things--but you cannot buy VCS/trac without spending $2900. If the other stuff is unimportant to you, as it was to me, then VCS costs $2900.

More importantly, I disagree that you need VSC and TRAC to help ABS and EBD stop the car from skidding. ABS works hard to stop the car as quickly as needed without the car losing control or skidding. It senses the skidding and modulated the brakes to prevent it. It doesn't make sense to me that VCS or TRAC would add any further control to this.

I liken this discussion and the value of VCS/TRAC to ABS. Anti-lock brakes were sold initially as being a tremendous technology to prevent accidents. It didn't turn out to be that way, statistically speaking. In practice, they have little effect on accident rates, not like the engineers initially thought. Similarly, VCS sounds like a great idea. But the jury is out.

wwest

If Trac is working it makes it impossible to "buzz", spin, the front wheels with engine torque.

So I stand quite firmly behind my statement that for understeering, plowing, the only appropriate thing for VSC to do is to apply the rear brakes. If the condition resulted from steering inputs then the operator could recover by lightening the steering angle slightly, the very thing BMW plans to have their "VSC" do automatically.

wwest

If you have any late model vehicle you can read the owners manual wherein it says that ABS is NOT there to help you stop, but IS there to help you maintain control while PANIC stopping.

The industry is reacting to having been BURNED by relying on salesman to get the word out about the functionality of ABS and now they are working diligently to correct the public's knowledge base.

A lot like the Bushies now telling the truth about the twin tower terrorist's point of origin. Their salesman in chief sold the public a load of poles.

wwest

An example.

My 92 LS will apply the brakes and simultaneously dethrottle the engine. I often had to merge into some serious traffic on a busy thourofare from a residential street. If the street was even slightly wet then the rear tires would lose traction on the plastic crosswalk striping and then not regain it on the slippery asphalt.

So I would find myself halfway out into traffic with no motive power available for what seemed like forever. Actually probably only a second or so for the ecu to reverse the dethrottling.

After only one or two of those instances I learned to disable Trac whenever it rained.

But I did notice that my 00 GS had enough delay in the dethrottling effort to give me time to react and lift my foot enough to regain traction, a rather significant improvement.

user777

and recently, i saw something on the national news about data recorders which might find their way into vehicles and help in accident investigations, etc.

now imagine that for whatever reason, you get into an accident, and someone has to download the data recorder to find out:
  a). what you were doing for control inputs preceeding and during the event
  b). what the system was doing with those inputs and its own inputs

...you might need a good lawyer and engineer on your team...you might find it awfully problematic to gain access to that data...assuming you get it, then you need expertise to reduce it.

driver driver driver... does the automation always support a driver that "knows what they are doing"?

anyway, i'm sorry, maybe it's just me, but i have a problem with someone else deciding on a scenario where the engine output should be de-rated when my control system input says "stay the same or increase".

I'd like to know if somebody runs that experiment to see if the VSC is derating the power during turns...

Power can be an asset in avoiding an accident. When I ask for power, I don't expect hesitation. That might lead me to either: try to demand more power...and when the system catches up with me, i really take off, or I completely let off the gas thinking the system isn't responding properly...

nojoy either way.

kmead - thanks for the hyper links.

muwarrior

Let's bring the discussion down a level. Is anyone aware of a place to purchase non-factory floor mats that actually fit the 2004 Sienna? My wife bought the most expensive mats Target sold ($20 for the set) and they look like $20 mats in a $27000 van. I guess you get what you pay for.

I still can't wrap my brain around the idea that I have to pay extra (especially $200+ extra) for floor mats. How long before you have to pay extra for carpeting the vehicle?

wwest

It is a lot more hazardous to add power to a FWD vehicle in a turn than it is a RWD.

The BIG problem with all of this automation is that it offers no way for the operator to understand just what has gone wrong. How do you "learn" from your misstrakes if you don't know what the system is reacting too.

The ABS is my ideal in that you get direct feedback to your mind as to just what is going on.

Were I a BMW designer instead of counter-steering the car, "taking the steering wheel from the drivers hands", I would use the stick-shaker approach to advise the operator that something is wrong and I would bias the vibratory nature of the shaking to let the operator know how to correct.

Without some input to the oeprator as to what happened and what corrective action the system made it cannot be a learning experience. Therefore VSC can never be anything more than a wider set of tires with more contact patch.

In short, if I don't know how and why I have exceeded the limits of the vehicular dynamics just what is to keep me from going there repetitively, and beyond?

vaeagles1

www.mats.com - has all kind of mats, including mats for the 04 Sienna.

rorr

"A lot like the Bushies now telling the truth about the twin tower terrorist's point of origin."

This is an automotive discussion board, not a political viewpoints board. You can either try to inform people or drive them away. Your choice.

"It is a lot more hazardous to add power to a FWD vehicle in a turn than it is a RWD."

Wrong.

Basics: in a FWD car, the front tires are attempting to exert force on the 'roadbed' to accelerate the car and/or to provide steering. In a RWD car, acceleration forces are exerted through the rear tires. Okay?

Important concept: additional downward force (through either static mass supported by the drive wheels or force from 'weight transfer' arising from either accelerating or decelerating) will aid in traction.

How does 'weight transfer' affect traction? In a RWD vehicle accelerating in a straight line, there is weight transfer to the rear, aiding in traction to the rear tires. Conversly, in a FWD vehicle accelerating in a straight line, there is weight transfer, again to the rear, which decreases the available traction at the front. This a one of the reasons why traditional dragsters are RWD.

So far, so good. I think we're all on the same page.

Now, lets discuss situations with somewhat reduced traction (rain, snow), curves in the 'roadbed' and RWD vs FWD.

When you say that one option is more 'hazardous' than the other, I assume that in both cases (FWD and RWD) we are talking about instances in which the driver has attempted to apply more force to the drive wheels than the available traction can provide. In other words, unless corrective action is taken, loss of control is imminent.

In case #1, the RWD car, the first clue that loss of control is imminent is when the rear-end of the car has lost traction and the car begins to go sideways (remember, we are talking about loss of control due to the application of power in a turn; this is YOUR scenario). The instinctive reaction of the driver is to let up on the gas and/or apply the brake. The effect of this is weight transfer to the front of the car AWAY FROM THE END WHICH HAS BEGUN TO LOSE TRACTION. You've increased traction to the end which steers but reduced traction to the end which was already lose. Result? Off the road backwards, perhaps after a 360 or two.

In case #2, the FWD car, the first clue that loss of control is imminent is sudden lack of steering feel (as you attempt to steer through the turn) and the front end of the car pushes out. Once again, the instinctive reaction of the driver is to let up on the gas and/or apply the brake. And once again, the result is weight transfer to the front of the car. But the difference with a RWD car? Now you have INCREASED traction to the end which was sliding.

Again - when you drop the throttle or apply the brakes in a skid (instinctive reaction for 95% of drivers) you DECREASE the available traction for the oversteering car (RWD applying power in the turn) while you INCREASE the available traction for the understeering car (FWD applying power in the turn).

It is my contention that you are always better off INCREASING traction to the end of the car doing the sliding. Perhaps you can explain why this is not the case?