Two problems related to electric power assist steering system have been reported for the 1999 Chevrolet Suburban. The most recently reported issues are listed below.
Streering began to act eratically and felt as if I hit a patch of ice with a rapid release of turning force while making a right hand turn. On the first occasion when this occurred I was exiting a freeway cloverleaf in wet conditions and the eratic movement caused the rear of the truck to lose traction and a near loss of control. I was able to recover the the slide without an accident but found it to be an unnerving event. After researching auto forums on the web I have found numerous postings on this subject and it is related to a failure of the steering wheel sensor located at on near the base of the steering column in the passenger compartment. I replaced this sensor on 05-04-05 and the condition is now corrected. I purchased the gm part #26064468 at a dealer and did the labor myself. This is an extremely hazardous defect which will inevitable cause a serious accident, especially in adverse weather conditions.
While driving the electronic module for the steering failed. As a result, the steering wheel became playful, and driver almost lost control.