LEMON Manuals: Even more car manuals for everyone
Home >> Pontiac >> 2007 >> Grand Prix Base >> Repair and Diagnosis >> Accessories & Equipment >> Gauges & Instrument Panels >> Instrument Panel System Displays And Gauges >> Diagnostic Information and Procedures >> DTC B3621 >> Circuit/System Testing

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the head-up display (HUD) switch.
  2. Test for less than 1.0 ohm of resistance between the HUD switch ground circuit and ground.
    • If greater than 1.0 ohm, test the HUD switch ground circuit for an open/high resistance.
  3. Ignition ON, verify that a test lamp does not illuminate when connected between the HUD image down switch signal circuit and B+.
    • If the test lamp illuminates, test the HUD image down switch signal circuit for a short to ground. If the circuit tests normal replace the HUD.
  4. Install a 3-A fused jumper wire between the image down switch signal circuit and ground. Verify the scan tool Adjust Display Down Switch parameter is Active.
    • If not Active, test the image down switch signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the HUD.
  5. If all circuits test normal, test or replace the HUD switch.
scientia non olet · About LEMON Manuals