Last post on Jan 26, 2013 at 11:00 AM
You are in the Toyota Highlander Hybrid Maintenance & Repair
What is this discussion about?
Toyota Highlander Hybrid, Brakes, SUV
#128 of 137 Re: Hi Hy Brake issues [paracletos]
Nov 20, 2010 (4:31 pm)
I recommend filing a complaint online with the National Highway and Transportation (NHTSA). It takes 2 minutes, and that is the way that we can all band together to show that there is a problem, regardless of what Toyota says!
#129 of 137 Re: Hi Hy Brake issues [cdptrap]
Nov 21, 2010 (11:53 am)
"..everything "heats" up.."
Yes, including the tire treads.....
Keep in mind that you are driving a FWD vehicle that is potentially a very DANGEROUS vehicle to be driving on a wintertime adverse condition, slippery, roadbed. Add to that the fact that your hybrid "wants to" make use of regen braking, FRONT WHEEL BRAKING ONLY, as a priority, a HIGH priority, and you have a somewhat (potentially) deadly mix of technologies.
Loss if traction, even momentarily so, on the driven, FRONT, wheels of your vehicle is a matter that requires INSTANT and URGENT attention. On a standard FWD with TC even the slightest level of wheelspin/slip arising from too much engine torque being used for conditions will result in INSTANT TC activation, engine dethrottling and braking of the engine driven wheels.
ABS is simply the "inverse" of TC, prevention of wheel lockup or skidding MUST be attended to INSTANTLY otherwise loss of directional control leading to an accident it far too likely.
So, with even the detection of the slightest level of impending (IMPENDING) front wheel lockup or skidding due to regen braking the braking mode MUST be switched. Regen braking, FRONT ONLY BRAKING, must be quickly disabled in favor of frictional braking ONLY, front and REAR frictional braking.
So, now, how should that transition be handled...?
The initial application of frictional braking in this instance MUST be, by default, calculated at the factory to be LOWER than the previous regen level. Otherwise we would soon find ourselves in the very same "boat"....impending wheel lockup/skidding and continuing ABS intervention.
So yes, in these instances, transitions from regen braking ONLY to frictional braking as a result of impending wheel lockup detection there MUST BE a transitional period of "lighter" braking. I don't see that the design engineers had much of a choice in this matter.
#130 of 137 Regen braking vs OAT.
Nov 21, 2010 (11:58 am)
On the hybrid Escape series Ford uses a regen braking control technique wherein the level of regen braking allowed before transitioning to combined regen and frictional is modified as a function of OAT. The colder it gets the less regen braking will be allowed before frictional braking is included.
Your HH might well have the same feature. And/Or more likely the "gain" used to detect impending lockup is increased as the OAT declines below, say, 35F.
#131 of 137 Upcoming Technology, Curve Control.
Nov 21, 2010 (12:02 pm)
The new FWD or F/awd Ford Explorer has a new technology they refer to as Curve Control. It seems to operate by dethrottling the engine and the use of braking if the system decides that you're driving to fast for the road curvature.
It'l be interesting to know how well that works in real life conditions....
#132 of 137 Re: Hi Hy Brake issues [mimers]
Nov 21, 2010 (12:02 pm)
Forgot to mention that I did post the incident on NHTSA months ago.
#134 of 137 Re: yotacro [yotacro]
May 17, 2011 (8:19 am)
I agree with you. I have called toyota who tell me to see a dealer. Why, so they can charge me $100 to tell me nothing is wrong with my vehicle. I can't tell you all how happy I am to have found this forum so I know I'm not crazy.
In my experience the slight shift of acceleration or lurching forward happens at less than 15mph and maybe at even less than 10mph. It is just very surprising and disturbing when you have to "all of a sudden" add extra braking power as you are coming to a stop.
#135 of 137 Hybrid slip regen
Sep 23, 2011 (7:53 pm)
Contacting Toyota or Gov has proved useless in spite of similar problems on other models of Toyota.
They will only pay attention to a class action suit unless there deaths (see acceleration problems).
Let's get together and sue them and maybe we'll get their attention!!
#136 of 137 Re: yotacro [utschy]
Sep 24, 2011 (9:37 am)
That "lurch forward" is the result of the coastdown full fuel cut technique being disabled due to the road speed now being too low to sustain the engine above stall.
During coastdown periods the engine is starved of fuel, FULLY starved, and the transaxle is sequentially downshifted in order to keep the engine turning over above the point of stalling. Once a "too" low speed is reached fuel flow is restored and the transaxle is upshifted. That last bit is why you feel a "lurch forward", due to the "relaxation" of engine compression braking.
#137 of 137 Do not buy it
Jan 26, 2013 (11:00 am)
I drove 2009 Highlander in Oct 18 2012 at 2:30 from the dealership,and at 12:00am Oct 19 2012,it was back in the dealership parking lot.I hit the side barrier and no air bag were enagged, as i side the side of the truck which kept on moving in spite pressing the brakes.
The truck slipped in black ice at 60 kmh, and failed to be controlled as the brakes did not even slow down it as there were dry patches too,but i did not have winter tires then.I got this truck repaired on Dec 18th 2012.
The highlander was in the dealership body shop for two months.
After driving for three weeks,Jan 22nd 2013, i had a second accident this at the speed of 25kmh at the play ground zone as the second car ahead stopped with no apparent reason,but my brakes failed again,this time had to apply the brakes hard as the low end delivery truck did and the highlander brakes failed even after pressing hard.
My first cost for the repairs were paid by my insurance and it was $15000