gmctd wrote:
A.) larger tires will cause more slip angle, output VSS to input VSS, also requiring more torque input, which ECM is ever sensitive to with resultant EMCC supervision, and
B.) the '06's have 4WABS with a tone sensor on each wheel hub, used for braking, traction control, etc in the ESP system ( '05's have RWAL brakes with a single sensor on the differential, and no ESP) - ECM\ABS\BCM\TCM each monitor some or all parts of those pulse inputs - won't take long for the ESP to start complaining at the change in parity first time the vehicle strays from a straight line - how do you exit your driveway?
I am trying to reason through this. Imagine a thought experiment where we put tires on our Jeep which have double the circumference of the factory tires. When we make a turn of a certain radius, each of the four wheels tracks a certain arc and the computer sees a certain differential between the wheel tones. Now, if we put those larger tires on our Jeep, the wheels still follow those same arcs and the
relative relationships between the wheel tones remain the same, but their absolute values are all cut in half. However, this would be no different signal-wise than making that same radius turn with the factory tires, but at half the speed.
What am I missing?
- Chris
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- remembering that the ESP also concerns itself with torque managment in event of loss of traction, tire slip, the larger tires not only have larger circumference, but larger footprint, not only from increased tread circumference, but also tread width - takes more torque to get them rolling, also more torque to roll them when the inside tire is pivoting amongst itself with little forward travel, as in a short-radius turn from dead stop - the system is not only concerned with differential tone frequency input, but acceleration\deceleration rate between each pulse - torque management is comparing Accelerator Position Sensor input to Crank Position Sensor to transmission Input Speed Sensor to transmission Output Speed Sensor to input from Transmission Range Sensor switches, monitoring shift accumulator response times, to tone wheel input from each wheel - it really is an intelligent system, not just counting frequency pulse differences, and I s'pect that, if there is considerable fuzzy logic involved, it wasn't programmed to account for the American redneck psyche, where bigger is always better - thus, the ability to defeat the ESP - the TSB05-001-08 (also known as the redneck recovery reflash) resulted from early 4wd '06's giving erratic ESP symptoms with larger tire sizes and other mods, which requires the reflash...................
Was misreading your post and was thinking the other way... that you had said the reverse. Oh well, driving in snowstorms with high winds will do that to a person. Thanks, Darby
