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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 2006 (Engine Controls And Fuel - 2.4L - DTC P1516 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. NOTE: Disconnecting the throttle body harness connector causes additional DTCs to set.
  2. Ignition OFF, disconnect the harness connector at the throttle body.
  3. Ignition ON, verify that a test lamp does not illuminate between motor control circuit terminal B and ground.
    • If the test lamp illuminates, 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 illuminate between motor control circuit terminal A and ground.
    • If the test lamp illuminates, test the 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 motor control circuit terminal A and B+.
    • If test lamp illuminates, test the 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 motor control circuit terminal B 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 circuit terminal B and ground.
    8. NOTE: When measuring peak voltage, ensure that the DMM is on the proper voltage scale that the response time is set to 1 ms.
  8. Measure for B+ on the motor control circuit terminal B as the ignition is turned ON.
    • If the peak voltage is not within 1 volt of B+, test for an open/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 terminal A circuit and ground.
  10. Measure for B+ on the motor control circuit terminal A as the ignition is turned ON.
    • If the peak voltage is not within 1 volt of B+, test for an open/high resistance. If the circuit tests normal, replace the ECM.
  11. If all circuits test normal, replace the throttle body.
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