Manual:HUMMER Hummer H3 Base 2010Page:23294 / 37523



Circuit/System Testing — 2010 Hummer H3 Base, Automatic Service Manual

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the mode actuator.
  2. Test for less than 1 ohm between the low reference circuit terminal 1 and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the HVAC control module.
  3. Ignition ON, test for 4.8-5.2 volts between the 5-volt reference circuit terminal 3 and ground.
    • If less than the specified range, test the 5-volt reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
    • If greater than the specified range, test the 5-volt reference circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
  4. Test for 4.8-5.2 volts between the signal circuit terminal 2 and ground.
    • If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the HVAC control module.
    • If less then specified range, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the HVAC control module.
  5. Connect a test lamp between control circuit terminal 4 and control circuit terminal 5.
  6. Command the mode actuator door in both directions with the HVAC controls. The test lamp should turn ON and OFF when commanded in both directions
    • If the test lamp does not illuminate in both directions, test both control circuits for a short to ground or an open/high resistance. If the circuits test normal, replace the HVAC control module.
  7. If all circuits test normal, test or replace the mode actuator.