Join Date: Feb 2017
Location: St. Louis, Missouri
The thing is, though...
Before the new tires, no TC light on. After the new tires, the TC light comes on. What changed? (Hint--the tires!). A damaged or loose wheel speed sensor would have the ABS light coming on either intermittently or constant, a damaged sensor wire harness would have the ABS on all the time. Is it possible to have slight rear wheel spin on accel and not feel it while the TC system is doing its thing based on a difference in measured wheel speeds with the new tires? Or is there a larger difference in tire diameters that fool the sensors into thinking there is a loss of traction?
With as many tires as Ive done on peoples' bikes through the years, Ive gotten into the habit of measuring the circumferences of the old tires before I deflate them, and the circumferences of the new inflated tires for comparison and dividing by 3.14 to compare diameters.
Seeing as how the TC is a function of the ABS system, TC diagnosis is done by jumping the ABS mode select coupler and counting flashes of the ABS indicator light.
Going through the ABS section of my '14 DL1000 service manual shows 25 flashes=CodeC1625=Wheel Speed Sensor Related Malfunction.
The very 1st item listed as a possible case is "Incorrect Tire Size", followed by "Check that the specified tires are installed."
Yes, tires can show the correct size on the sidewall, but have a different outside diameter, which changes the wheel speed sensor reading and trigger a malfunction light. Most of the cars TC and ABS systems I dealt with had warnings in their service manuals that a difference in tire diameters over 1/4 BETWEEN the tires could trigger a warning light.
in both ABS and TC operation the ABS control unit is looking at the difference in wheel speeds, be it by a wheel locking up during braking or spinning during acceleration.