This sounds like a problem with the shift control solenoid at the base of the steering column. Further electrical testing should be performed by a techician competent in GM systems with a scan tool capable of entering and
setting the passlock antitheft system if necessary.
Jim O’Neill – Chino Autotech Inc., Auto Club SoCal AAR
SAE Int’l SoCal Section Board of Governors,
Vice Chair, Service Technology Programs
NASTF Service Information/Communications Committees
Auto Value/Bumper-To-Bumper CSC Nat’l Council
ASE CMAT-L1, CA. Smog Check Technician
AMI AAM Accredited Automotive Manager