Hello! This is usually the result of a wheel speed sensor issue. Most technicians look for WSS fault codes, to decide which one is failed, but if there are no fault codes, they don't know where to look. The trick, is with the scantool hooked up, watch the ABS solenoids and see which ones activate during the traction event. If the Wheel Speed Sensor is acting up, it can confuse the ABS module into thinking that wheel is slipping and it will activate the ABS pump and solenoids for that wheel, to try and slow it down.
With the stability system disabled, it won't try and slow the "slipping" wheel down, which is why it won't do it when disabled.
and the noise you hear is probably the ABS motor and solenoids, which are mounted on the Left Frame Rail, below the drivers seat (often heard at the firewall).
There was a bulletin to replace the Yaw Rate Sensor and update the ABS Software, which is probably where the $400 went, and it may have needed it, but obviously that wasn't the problem. I beleive that the issue lies withing the Wheel speed sensors.
the most common symptom of speed sensor failures is premature ABS activation, but I have in some instances see it cause Traction Control events take place as well. Here is a service bulletin for unwanted ABS activation:
Antilock Brake (ABS) Activation At Low Speeds (Clean Wheel Speed Sensor Mounting Surface)
2002-2006 Cadillac Escalade, Escalade EXT
2003-2006 Cadillac Escalade ESV
1999-2006 Chevrolet Silverado
2001-2006 Chevrolet Suburban, Tahoe
2002-2006 Chevrolet Avalanche
2003-2006 Chevrolet Express
1999-2006 GMC Sierra
2001-2006 GMC Yukon, Yukon Denali, Yukon XL, Yukon Denali XL
2003-2006 GMC Savana
2003-2006 HUMMER H2
Read more: http://www.justanswer.com/chevy/1s7al-2004-tahoetraction-control-turns-during-acceleration.html#ixzz3OcuhIIbz
HOPE THAT HELPS