LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2007 >> CTS Base, 2.8 T, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 220 (Cellular System, Entertainment System, And Navigation System) >> Diagnostic Information and Procedures >> Unable to Contact OnStar Call Center >> Component Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Component Testing

WARNING: This page is about a different car, the 2007 Cadillac STS. However, it is still accessible from the selected car via links, so may be relevant.
IMPORTANT: Vehicle may be equipped with sectioned coax. Test each section and replace only the faulty section, not the entire length or coax.
  1. Verify that there is no exterior damage to the cellular antenna.
    • If damaged, test or replace the cellular antenna assembly.
  2. Disconnect the cellular antenna coax from the VCIM.
  3. Disconnect the cellular antenna coax from the cellular antenna.
  4. Test for infinite resistance between the center conductor of the coax and the outer metal shield.
    • If different than specified value, replace the cellular antenna coax.
  5. Test for less than 1 ohm resistance at the cellular antenna coax center conductor from end to end.
    • If greater than specified value, replace the cellular antenna coax cable.
  6. Use the scan tool to access the STID, ESN and Transceiver I.D. and contact the General Motors Technical Assistance Center.
scientia non olet · About LEMON Manuals