Quote:
Originally posted by spookysco@Dec 25 2006, 01:34 AM
I expect a car to give me power when I apply the 'gas'. This car didn't do that but instead did nothing. Now that I've been through this I can see other instances (as I have already discussed) where this "feature" could be a safety issue. Not something I'm willing to go through.
Being stuck is one thing, having the "feature" kick in on an incline could be disasterous.
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Some people spin the
tires at high RPMs while jamming the transmission between forward and reverse as a method to get unstuck. This is significantly damaging to any vehicle drive train. A much more gentle application of power to create a rocking motion is just as (or even more) effective and does not harm the transmission if done correctly.
If the vehicle skidded off the road and is propped up in a snow bank, resting mostly on the frame and underside rather than the wheels, you are toast in any vehicle without a bumper winch and a nearby tree.
I believe that the VDIM response in the Highlander Hybrid to a stuck-in-the-snow condition could be improved. Since the accelerator is a by-wire system, the powertrain computer (not the driver) has control of throttle response from the engine and motors. Under the proper conditions, the wheels should be allowed to turn at a slow controlled speed and for a controlled duration when the accelerator pedal is pressed and the vehicle is stationary or traveling less than 5 mph. The Highlander has RPM sensors at every wheel and knows when the vehicle is not moving. Such controlled wheelspin would not have any negative effect on the hybrid powertrain since the output power and duration would be limited within safe parameters.
A controlled wheel spin mode is definitely not such a good thing when driving on glare ice where a much more gentle application of power without wheel spin is needed to keep the vehicle under control. The vehicle probably can not discern the difference between sitting on glare ice and being stuck in a snow bank so it rightly and safely defaults to a glare ice strategy. The powertrain computer needs input from the driver as to what traction strategy to use.
I propose that shifting the vehicle into B could put the vehicle into the controlled wheelspin mode for snow or steep gravel/dirt roads while D would handle glare ice and normal driving. All that would be needed is a revised program to be flashed into the drivetrain computer. Being realistic, Im not holding my breath for such a modification from Toyota.