Traction control won't disengage.

problem usually narrows down to abs system problem or hub failing causing problem with abs --have vehicle scanned for the trouble code it will assist you as where to start in repairing problem most auto stores offer this service for free --in the mean time pull the abs fuse so brakes can revert to a normal non abs system till repairs can be made

Nicole, I google it and the 06 Cadillac STS does appear to have a ignition relay. It will most likely be found in the engine compartment fuse/relay box. Check the attached links,instruction and guides, Good luck
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http://www.rockauto.com/en/catalog/cadillac,2006,sts,4.6l+v8,1432044,electrical-switch+&+relay,ignition+relay,3480
2006 Cadillac STS ignition relay Google Search

The fuse is located under the rear seat in the fuse box.Trunk/valet fuse.

Cadillac has a cruise control system that becomes disabled when there is a fault in either the suspension, abs, traction control, or engine management system. The car needs to be scanned to find the cause

On this website you find information (diagram, description and location) about fuse boxes in Cadillac STS mk1 (First Generation; 2005 - 2006)

Cadillac STS mk1 First Generation 2005 2006 fuse box diagram Auto Genius

If the brake light is on, check the fluid level immediately and add fluid if necessary.
After that, have the car's OBD-II computer scanned with a 'Brake Scan' tool for OBD-II. This will help to narrow down which wheel speed sensor is giving you trouble. It might be a broken wire, or a bad wheel speed sensor.

The wheel speed sensor sends information to the ABS side and the Traction Control side of the computer module for ABS and Traction Control.

The car will revert to standard braking and regular non braking transmission power distribution to the drive wheels when the ABS and Traction Control lights are both on.

Good luck on this repair.

Hello: The traction control works through the Anti-Lock, The Powertrain control module. Initial control is through the ABS, IT WILL APPLY THE BRAKE TO THE FASTER WHEEL TO SLOW IT DOWN. If there is not enough progress it will then request the PCM to ****** the engine timing, if there is still not sufficient response it will cut off fuel to some cylinders. All of this happens very quickly.

most of the time it occurs after replacing a battery but if this occurred out of the blue then something like the transponder has failed

you'll need a professional scan tool and about an hour to diagnose the concern

then when fixed, you'll need another 30 minutes to reprogram the computers and keys

one under the hood one on the drivers side of the dash

you need a scan tool. go to auto zone they will do it @ no charge good luck.