aah...traction control [img]smile.gif[/img]
there are 2 different ways I know of for how traction control works. Both work via detecting slip in the drive wheels.
on cars with TRACS such as the volvo 850, the traction control works via ABS brake system. If one of the wheels encounters slipping, the abs system will start pumping on that particular wheel until traction is gained. I do not know if this is only for the drive axles or not.
2. power output
on cars with TRACS as a toyota supra, the traction control works based on the throttle body. there is another throttle body that is in front of the main throttle body. this throttle body is normally 100% open. if the ECU detects slipping, the throttle body will close to lower power output until the wheels gain traction.
in your case, since you have a toyota (lexus), you might be able to take off the glovebox where you should find 3 different aluminum boxes or what not. one is the ECU, one is the ABS unit, and the other should be the TRACS unit. Disconnect the TRACS unit and kiss goodbye to TRACS [img]smile.gif[/img] the TRACS light might come on tho.
in addition to the 2, i believe volvo and VW in addition to other manufacturers, there is another method of TRACS which I personally like very much. The VW 4-motion and volvo AWD are not true 4WD vehicles, but front wheel drive biased (90 power front, 10% power rear). If slip is detected in the front wheels, the TRACS via a viscous clutch or haldex transfer system, or some other method, will transfer up to 80% of the power to the rear wheels (10% front 90% rear). In icy situations, this is the only method, imho, aside from true 4wd that TRACS will help. Reason being, if even one of the wheels have some grip, the car will move. THe negative side of this? it's mechanical so it will only work as fast as the power transfer...i encountered this situation today [img]smile.gif[/img] .
the only vehicle that has a superior TRACS system to everything else out there is a nissan skyline...unortunately, not available here. the atessa ets system electronically controls the 4wd. it's a true 4wd, but the system will instantly drop power to the wheels that are slipping unlike viscous clutch which takes a moment to work [img]smile.gif[/img]
hope this helps