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Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 1710 (Engine Controls And Fuel - 3.6L (Ly7) - DTC P1174 To DTC P2635) >> DTC P1516, P2101, P2119, or P2176 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2009 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.
WARNING: Turn OFF the ignition before inserting fingers into the throttle bore. Unexpected movement of the throttle blade could cause personal injury.
  1. Inspect the throttle body for the following conditions:
    • A throttle blade that is NOT in the rest position
    • A throttle blade that is binding open or closed
    • A throttle blade that is free to move open or closed WITHOUT spring pressure
    • If a condition is found, replace the throttle body.
  2. Ignition OFF, disconnect the harness connector at the throttle body.
  3. Ignition ON, verify that a test lamp does not stay illuminated between the motor control 1 circuit and ground.
    • If test lamp stays illuminated, test the motor control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Ignition ON, verify that a test lamp does not stay illuminated between motor control 2 circuit and ground.
    • If test lamp stays illuminated, test the affected motor control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  5. Ignition ON, verify that a test lamp does not illuminate between the motor control 1 circuit and B+.
    • If test lamp illuminates, test the affected motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  6. Ignition ON, verify that a test lamp does not illuminate between the motor control 2 circuit and B+.
    • If test lamp illuminates, test the motor control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  7. Ignition OFF, allow sufficient time for the ECM to completely power down. Connect a DMM between the motor control 1 circuit and ground.
    8. NOTE: When measuring peak voltage, ensure that the DMM is on the proper voltage scale and the response time is set to 1 ms.
  8. Using the peak min max function measure for ignition voltage on the motor control 1 circuit as the ignition is turned ON. The voltage should be within 1.5 volt of the ignition voltage.
    • If not the specified value, test for an open or high resistance. If the circuit tests normal, replace the ECM.
  9. Ignition OFF, allow sufficient time for the ECM to completely power down. Connect a DMM between the motor control 2 circuit and ground.
  10. Using the peak min max function, measure the voltage on the motor control 2 circuit as the ignition is turned ON. Voltage should be within 1.5 volt of ignition voltage.
    • If not the specified value, test for an open or high resistance. If the circuit tests normal, replace the ECM.
  11. If all circuits test normal, replace the throttle body.
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