'05 Prius VCS

prius

#1

Does anyone know how to disconnect the Vehicle Control System on this model? We have a terrible time with traction up steep gravely roads or in driving on snow. The engine dies in the middle of the effort and makes for a VERY scary and frustrating situation.



Toyota says it can’t be done.


#2

Are you talking about the traction control system? Toyota wouldn’t tell you how to disconnect it even if they knew, because it would expose them to enormous liability issues

Considering the complexity the drive train on a Prius, it’s possible that the traction control CANNOT be disabled, and if it could it would also disable the ABS, since they both take their information from the same wheel speed sensors.

If it helps, yours is not the only such complaint about vehicles (not just the Prius) equipped with traction control. Sometimes when traction is limited the engine will just go to idle and there is nothing you can do. To be honest, I’m glad my vehicles are old enough not to have all this “feature.”


#3

Is VCS Toyota’s name for a Vehicle Stability Control (anti-skid) system or is it their name for a Traction Control system? Regardless, I can tell you that on my car, the anti-skid system and the traction control system can be both be disabled simply by pushing one button on the dashboard. In the Owner’s Manual, it suggests that the only time that this button should be pushed is when encountering poor traction on a surface like loose gravel.

I am very surprised that Toyota does not have a similar way of disabling those systems, and I suspect that something in the intricacies of the Synergy Drive system is the reason. You might want to place a telephone call to Toyota of America in order to speak with someone who has technical knowledge on this topic beyond what someone at the dealership might know.


#4

Hi,

I assuming that Toyota puts low rolling resistance tires on the Prius to maximize gas mileage. I have a car (93 Caprice) with low rolling resistance tires. For its size it gets great gas mileage, on the other hand driving in any rain is unnerving at best. Driving in snow is impossible, the so-called all season tires have no traction at all. I’m going to replace the tires soon, I’m willing to give up a little mileage to have a safer car to drive.

Rather than trying to disable the VSC, perhaps putting better tires with more traction might help. Even if you can disable the VSC, the OEM tire traction is not going to improve. Tire Rack (www.tirerack.com) is a good source for tires and tire info.

Good luck,

Ed B.


#5

There is a known problem with the traction control in the Prius. It seems to be shutting off the engine when it detects wheel slippage instead of just reducing power. See the link below for more info.

http://www.consumeraffairs.com/news04/2007/04/prius_traction.html


#6

Wow, what GREAT posts!! Thank you. The article confirms exactly what we were saying. And the dealership salesman left me a message that the issue has been fixed. We’ll see…according to the article from Consumer Complaints, an owner of an '07 says the problem still exists.


#7

Never believe ANYTHING the salesperson says. They will tell you what you want to hear.


#8

Neither the standard traction control, nor the optional Vehicle Skid Control (VSC), can be user-disabled. (Inspection mode, which’ll turn of the traction control, is for unmoving cars in a repair shop only!)

I think that you are commenting on the traction control, though.

Yes, a number of people have commented on the overly-agressive traction control… (The Classic Prius only had a simulated traction control, and not a full traction control like the NHW20 has, so it isn’t quite as bad.)

When a wheel is seen as slipping (spinning faster than the others), power is reduced to the wheels (to prevent damage to the transmission when the spinning wheel suddenly catches again). (Which is different
than the optionally-equipped VSC, which would help if you are moving in a direction different than where the wheels are pointed…)

Some have reported a hesitation when turning (say, on an onramp), which is usually the traction control kicking in with a wheel spinning on loose gravel or dirt on the side of the road in this turn.

Also, when traction control kicks in the regenerative braking stops and you go to full regular hydraulic brakes. This transition between regen/mixed to full hydraulic isn’t seamless, so if you are braking/slowing down when you hit the slippery patch (can also be a temporarily airborne wheel going over a pothole or a manhole cover), you may feel a sudden lurch or surge forward, causing you to press harder on the brakes.

In some slippery conditions, you may find that the traction control causes you to lose all forward momentum and stop… Supposedly, if you keep the pedal floored, it’ll eventually crawl itself up, but… (I’ve also heard that a light pedal might work just as well, but that may be a Classic thing rather than a NHW20 thing.)

If you require more help, I’d suggest a forum dedicated specifically to Prius owners.


#9

Ed B.
What is your experience with tires on the Prius? I’m getting ready to replace the 2nd set of tires on my 2002. The OEM Bridgestone Potenzas lasted 48k and the current Dunlop SP10s lasted over 50k miles. Both performed really well in the snow. My dealer is now pushing the Goodyear Integrity, but I’ve read some unflattering posts about these. Who to believe, my mechanic or blogs? Town Fair Tire recommends Toyo Spectrum, but I haven’t seen anything about these.
Anybody with experience on these they’d like to share, it’ll be greatly appreciated.
gid


#10

Ed B.
What is your experience with tires on the Prius? I’m getting ready to replace the 2nd set of tires on my 2002. The OEM Bridgestone Potenzas lasted 48k and the current Dunlop SP10s lasted over 50k miles. Both performed really well in the snow. My dealer is now pushing the Goodyear Integrity, but I’ve read some unflattering posts about these. Who to believe, my mechanic or blogs? Town Fair Tire recommends Toyo Spectrum, but I haven’t seen anything about these.
Anybody with experience on these they’d like to share, it’ll be greatly appreciated.
gid


#11

Hi,

I’m posting a link to www.TireRack.com for 2002 Prius tires.

http://www.tirerack.com/tires/Compare1.jsp?sortValue=1&filterType=all&resultsNumberSelected=Y&displayResults=10&compare=true&autoMake=Toyota&autoModel=Prius&autoYear=2002&autoModClar=&vehicleSearch=true&compareList=&RunFlat=All&goWhere=%2Ftires%2FCompare1.jsp&minLoad=S&loadRank=2&minSpeedRating=S&sortCode=33400&width=175%2F&ratio=65&diameter=14&speed_rating=S&speed_rating=T&speed_rating=U&speed_rating=H&speed_rating=V&speed_rating=Z&speed_rating=W&speed_rating=Y&performance=HPAS&performance=PAS&performance=GTAS&performance=ST&performance=AS&startIndex=0

Of the 28 Tires on the list the Yokohama Avid T4 and Touring are near the top of the list in their performance categories.

Ed B.

I had Goodyear Integrity tires on my 1998 Windstar. They were ok on the van, but not


#12

I had Goodyear Integrity tires on my 1998 Windstar. They were ok on the van, but not exceptional.

Oops, hit the Submit instead of the Preview button.

Ed


#13

What is your experience with tires on the Prius? I’m getting ready to replace the 2nd set of tires on my 2002. The OEM Bridgestone Potenzas lasted 48k and the current Dunlop SP10s lasted over 50k miles. Both performed really well in the snow. My dealer is now pushing the Goodyear Integrity, but I’ve read some unflattering posts about these. Who to believe, my mechanic or blogs?

US 2001-2003 NHW11 OEM Prius tire:
Bridgestone Potenza RE92 XL (Extra Load)
P175/65 R14
84S
Treadwear 160
Temperature A
Traction A
50psi max. cold pressure

Canada 2001-2003 NHW11 alternate OEM tire
Dunlop SP10 XL
P175/65R14
84S
treadwear 220
traction A
temperature B
50psi max. cold pressure

With the change in models beginning in the 2004 model year, the tire size (and also brand) changed:

US/Canada 2004-2007 NHW20 OEM Prius tire:
Goodyear Integrity (Standard Load)
P185/65 R15
86S
Treadwear 460
Traction A
Temperature B
44psi max. cold pressure

Since the tire size changed on the newer Prius, that’s probably why your Toyota dealer thought about the Goodyear Integrity tires for your 2002 Classic (but that’s the wrong size…)

Toyota does have a TSB out (PG015-00) for the tires on the Classic Prius, stating that only those with the proper load rating in that size should be used (and only lists the Bridgestone Potenza RE92 XL or a similar Bridgestone Blizzak (snow) tire).

In the 175/65 R14 size, I’ve only seen 4 tires that meet the proper load rating of 84 that the US Classic Prius requires, not including the Bridgestone Blizzak snow tire:
Bridgestone Potenza RE92 XL
Dunlop SP10 XL
and:

Nokian WR
P175/65R14XL
86T
Severe Service Emblem (the only all-season tire on the market that is
also a snow tire (denoted by this emblem), to my knowledge)
(I think:
400 treadwear
A traction
A temperature
I don’t recall if it’s 44 or 51 psi max. cold pressure)

and also:
Barum Brillantis
175/65 R14 86T XL

In order to keep the proper load rating, several Classic Prius owners have changed the tire size slightly to find more available tires, or they must religiously check for wear and tire pressure on a standard load tire in the proper size. See: http://john1701a.com/prius/prius-tires_classic.htm for some suggestions.

Personally, with the low treadwear rating on the original Bridgestone Potenza RE92 XL tires that came on your car, I’m quite surprised that you got 48k miles out of them! Most owners tend to report in the 20-30k miles for those tires.

Reports on the Goodyear Integrity tires that are now on the new Prius, well… Some people go as far as to change them out immediately when they get the car. My personal experience with them is that they’re OK for maybe your first winter, but after that I wouldn’t trust them in winter or heavy rains. They’re OK summer tires, but there are much better alternatives out there. I see a lot of suggestions for the Michelin Hydroedge tires. (Myself, I’m currently using the Nokian WR on both of my 2001 and 2004 Prius.)


#14

Thanks for the thoughtful and detailed response. Sorry for the delay (I forgot which forum I was in!).
Don’t know if it changes your comments, but both sets of tires I had were LRR, not XL. I was told those get the best mileage.
I haven’t heard of the Nokian or Barum. Where do you find those?


#15

Stick with the OEM.

-Matt