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 >> OnStar One or More Buttons Inoperative >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System 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.
  1. Ignition OFF, disconnect the harness connector at the inside rearview mirror.
  2. Ignition ON, test for voltage between 9.8-10.2 volts between the supply voltage, terminal 6 and ground.
    • If less or more than the specified value, repair short to ground, open or replace the VCIM.
  3. Ignition OFF, reconnect the harness connector at the inside rearview mirror.
  4. Disconnect the C1 VCIM harness connector.
  5. Test for 500 to 20K ohms of resistance between C1 VCIM harness connector terminal 12 and 11 when each of the keypad button is pressed.
    • If resistance is within the specified value when any of the keys are pressed replace the VCIM.
  6. Disconnect the harness connector at the inside rearview mirror.
  7. Test for infinite resistance between the inside rearview mirror connector terminal 11 and ground.
    • If less than infinite resistance repair short to ground on the keypad signal circuit.
  8. Test for less than 1 ohm between the C1 VCIM connector terminal 11 and the inside rearview mirror connector terminal 11.
    • If more than the specified value repair open or high resistance on the keypad signal circuit.
    • If all circuits test normal, replace the keypad.
scientia non olet · About LEMON Manuals