I don't like it

Hey Folks:

Here in the Smoky Mtns of North Carolina we are always either going up or down. Our Tacomas have a stepdown feature that aids in holding the truck back on steep hills. I don't like that feature and would like to disable it. I feel as tho I am torturing the transmission. I'd rather replace the brake pads over the transmission.
About a year ago when I was having transmission troubles one of the symptoms was that the step down didn't engage. It turned out to be the "pigtail" attached to the Range Sensor on the side of the transmission. That "pigtail" also operates some vital components that are necessary to the normal operation of the truck. I need those but one of the wires signals the step down to engage when the brake is applied. Anybody know which wire I should deal with or how to accomplish the task in another way?
My truck is an 07 base model with the 4 L engine.

Bob

 

Not gona hurt anything by allowing the transmission to downshift on a grade, most transmissions with a tow mode will downshift to provide engine braking when tow mode is turned on. 2nd Gens do it by default to save fuel and provide a bit of engine braking.

If you want to change transmission behavior you would need a tune.

The reason it probably wasn't working correctly when the range sensor was messed up is it will go into failsafe mode when it get's invalid signals from certain sensors.

 

Not torturing anything. The transmission isn't slowing the vehicle down. It simply downshifts to let the engine slow the vehicle down. Spinning the engine faster against a closed throttle heats up the air in the cylinders (i.e. converting kinetic energy to heat), which is easily dissipated by the cooling system.

 

Totally fine to engine brake. Could help save your brakes for when you really need them!

 

"gears are to hold speed [up or downhill], brakes are to stop you"

Overall it's way safer to let it do this auto downshifting when riding the brakes. The 2nd gen 5 speed auto behind the V6 will downshift for speed holding all the way to 3rd gear in some instances on steeper descents. If you wanted to come up one gear at a time you can move the shifter from D to 4 back to D. If for some reason you wanted to go to full coasting (5th gear not in fuel cut) move the shifter from D to N back to D.

 

If you use your brakes for 100% of the downhill speed regulation, it’s almost certain the rotors will warp. Some vehicles are worse about this than others, and as the Tacoma by all accounts has merely adequate brakes, it is very likely to happen.

 

You aren't hurting the transmission in the least. Not downshifting will eat up your brakes a lot sooner and possible lead to brake failure in a bad place.

My truck has the feature, but I never notice it. I always manually downshift way before the truck does and I downshift to lower gears than the truck does. You do have to use some common sense. You don't wait until the truck is doing 50 mph then drop it into 2nd gear. Doing that could well break something. I also manually downshift going up hills to keep engine rpm's in the best range for power. The truck will eventually downshift, but it only does it AFTER the engine is struggling. It's better to do it BEFORE the engine starts to struggle.

 

What all the others said. There's a reason that big rigs use engine braking and downshifting to navigate the mountain passes and not brakes. When I go over donner pass in california , I don't ever even use the brake pedal (I'm a cdl driver)

 

The transmission will be fine. If it was that brittle it would be breaking just trying to move the truck up the hill