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Thread: Traction control system

  1. #1
    Senior Member AlphaMicra's Avatar
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    Traction control system

    In my old Grand Am GT, one feature I really enjoyed was the traction control system. I had come to learn that, upon reduction of traction, the computer would retard engine timing to reduce power and upshift the transmission - purely a software solution. Of course, this meant that Grand Am GT's only came with an automatic transmission, and stick shift 4 cylinder Grand Am's didn't have traction control.

    I wondered how Nissan did it in our Micra's. Assuming our Micra's are simply a re-implementation of existing technology, it appears that the throttle input is reduced (we have an electronic throttle, so the computer makes the throttle behave as though you lifted your foot from the accelerator), and the brakes are applied to all of the wheels.

    http://ramseynissan.com/2012/09/13/w...ontrol-systems

    Which system is better? It's hard to determine from the technical specs, I'll have to live with my Micra for a winter to answer that question. What I do know is that, in my old car, I could plant the gas pedal to the floor even on ice and snow and the car would work things out in the traction department fairly efficiently without undue wear on my brake pads; the upshift and retarding of engine timing always did the trick. However, the Micra's ability to control the throttle position seems like a better solution than the retarding of engine timing, and will probably mitigate undue wear and tear on the brake pads.

    I suppose my desire for the manual transmission makes Nissan's solution the better of the two.



    In our culture obsessed with absurd excess, the Nissan Micra is my counterculture car of choice.
    Be sure to visit my blog at mymicra.com!

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        click to view fuel log View my fuel log 2015 Micra SV manual: 6.4 L/100 km ... 44.3 mpg (Imp) ... 15.7 km/L ... 36.9 mpg (US) ...


  2. #2
    Administrator MetroMPG's Avatar
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    Have you tried it out yet? Gravel road... grass?

    The only part of the Micra's active safety kit I experienced in the loaner SR automatic was stability control. I heard a brief activation of the brakes on one side (which cancelled the cruise control, by the way) while playing a real life game of Frogger on a back roads drive home from Ottawa. (Where Frogger = flicking the car left/right to avoid smooshing the amphibious creatures that had chosen that evening to cross the road.)

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        click to view fuel log View my fuel log 2015 Micra S manual: 5.0 L/100 km ... 56.5 mpg (Imp) ... 20.0 km/L ... 47.0 mpg (US) ...


  3. #3
    Senior Member AlphaMicra's Avatar
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    I've felt the ABS come on briefly once when coming to a stop and hitting a deep puddle. I suppose grass would be safest, but I have a feeling winter will be here before we know it...

    In our culture obsessed with absurd excess, the Nissan Micra is my counterculture car of choice.
    Be sure to visit my blog at mymicra.com!

        __________________________________________

        click to view fuel log View my fuel log 2015 Micra SV manual: 6.4 L/100 km ... 44.3 mpg (Imp) ... 15.7 km/L ... 36.9 mpg (US) ...


  4. #4
    Senior Member Howie's Avatar
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    ours is better then the old gm traction control system as it has control over the brakes. It also has a g sensor and yaw sensor to detect slide.

    The old gm traction control doesn't have any ability to stop you other then its ABS...

        __________________________________________

        click to view fuel log View my fuel log 2015 Micra S automatic: 7.9 L/100 km ... 35.7 mpg (Imp) ... 12.6 km/L ... 29.7 mpg (US) ...


  5. #5
    Senior Member AlphaMicra's Avatar
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    I was out very early yesterday morning, and it was raining quite a bit. Given that it was so early on a Saturday morning, there were no other cars around, so I decided to put it to the test. I ran first gear out normally, but went WOT when I hit second, which normally would have caused the front tires to break free...which they did, but only for a split second.

    I could barely feel the tires break free; my first sign was the light on my dash. I confidently kept the gas pedal pegged to the floor, and noticed that, no matter how hard I pressed my foot to the floor, the engine acted as though I had taken my foot off the accelerator. As traction was regained, my Micra kept me at the threshold of traction all the way until I had to shift to third, a gear in which the engine would have a difficult if not impossible time breaking traction on wet pavement.

    The whole process was seamless and almost natural; it seemed to predict what I would have done under normal circumstances, but only better. I started to wonder, what if the traction control system was working without me even knowing about it? I'm not looking at the dash when I accelerate hard, so I wouldn't notice the light unless I was looking for it, and since the computer lets up off the throttle as I would have (but only much more quickly), perhaps the computer was predicting my own behaviour, causing my perception to be that of which my own driving skill had improved.

    I then came to realize that the low rolling resistance tires, combined with the traction control system, may have affected my 0-60 time without me being aware of it. That's when I realized, this is the best traction control system I've ever experienced. It's imperceptible to the driving experience, but has probably been saving me embarrassment since the day I bought the car.

    In our culture obsessed with absurd excess, the Nissan Micra is my counterculture car of choice.
    Be sure to visit my blog at mymicra.com!

        __________________________________________

        click to view fuel log View my fuel log 2015 Micra SV manual: 6.4 L/100 km ... 44.3 mpg (Imp) ... 15.7 km/L ... 36.9 mpg (US) ...


  6. #6
    Senior Member Howie's Avatar
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    you are correct. The micra has a fly by wire system- Sort of.

    The gas pedal in our cars are no more then a potentiometer, that is electronic. You push your foot down, the potentiometer reads the resistance as a value and converts it to how far the pedal is pressed down, the computer then reads the road speed, transmission speed and details from the ABS/TC system and then gives the engine the fuel you demand.

    If say the left front tire breaks free, under full power then the abs/tc system would show that it is rotating faster then the other three tires on the car and would either engage the front left brake, or reduce the fuel presented to the engine, if your going full monty on the car, reducing the amount of fuel would be the logical choice. This all happens in milliseconds.

    Now in a slide, it operates differently. Say your doing a forward right skid, as if you were going around a left hand curve and the car was skidding off the road into the ditch with your rear end starting to slide out. The sensors at each wheel would indicate that the tires on the right side of the car would show the differences in tire speed. Usually in that skid, your right rear wheel spins faster or slower then the right front, causing the back end to step out. It can then operate the left rear brake to pull it the car back in.

    Also, something we probably will notice being a FWD is the reduction of engine power at this time to help snap the nose of the car in. Again, this whole process takes mere milliseconds.

    Now this winter were going to see understeer. Understeer is where you steer fast and the car doesnt turn where it should and continues going straight. In this same corner if the front of the car started sliding straight instead of following the bend, you would see the power reduced to the front, possibly left front and rear brake application so the car veers inwards.

    What remains to be seen is how much or how little will this system activate in our cars. Some systems act like nannies, and others do not engage until the last possible second. Is ours a full traction control system? Or is it just an anti-spin program (I dont think it is).


        __________________________________________

        click to view fuel log View my fuel log 2015 Micra S automatic: 7.9 L/100 km ... 35.7 mpg (Imp) ... 12.6 km/L ... 29.7 mpg (US) ...


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    AlphaMicra (09-09-2014)

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