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Home >> Chevrolet >> 2006 >> Impala LTZ >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 3.9L - DTC P0010 To DTC P0420 >> DTC P0106, P0107, or P0108 >> Circuit/System Testing
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Circuit/System Testing

  1. Start the engine.
  2. Monitor the diagnostic trouble code (DTC) information with the scan tool.
  3. If DTC P0641 or P0651 is also set, then correct DTC P0641 or P0651 first.
  4. Inspect for the following conditions:
    • Disconnected, damaged, or incorrectly routed vacuum hoses
    • Manifold absolute pressure (MAP) sensor disconnected from the vacuum source
    • Restrictions in the MAP sensor vacuum source
    • Intake manifold vacuum leaks
    • Check for a properly functioning oxygen sensor, refer to Scan Tool Data List .
  5. With the ignition ON, and the engine OFF.
  6. Disconnect the MAP sensor.
  7. Measure for 4.8-5.2 volts from the 5-volt reference circuit of the MAP sensor to a good ground, with a DMM.
    • If more than 5.2 volts, then test the 5-volt reference circuit for a short to voltage or faulty control module.
    • If less than 4.8 volts, than test the 5-volt reference circuit for high resistance, an open, or an intermittent and poor connection or at the control module, or a faulty control module.
  8. Use a scan tool and observe the MAP sensor for less than 12 kPa.
    • If the MAP sensor is more than 12 kPa, then test the MAP sensor signal circuit for a short to voltage or a faulty control module.
  9. Use a 3-amp fused jumper wire and connect it between the MAP sensor 5-volt reference circuit and the MAP sensor signal circuit.
  10. Observe the MAP sensor for more than 103 kPa.
    • If the MAP sensor is less than 103 kPa, then test the MAP sensor signal circuit for a short to ground or high resistance or a faulty control module.
  11. With the 3-amp fused jumper wire still connected between the 5-volt reference circuit of the MAP sensor and the signal circuit of the MAP sensor, observe the MAP sensor parameter with the scan tool for 4.9V.
    • If less than 4.9V, test the MAP sensor signal circuit for a short to ground, an open, or high resistance, or an intermittent and for a poor connection at the control module, if tests OK then replace the control module.
  12. Turn OFF the ignition and allow the control module to power down.
  13. With a DMM measure for less than 5 ohms of resistance between the low reference circuit of the MAP sensor and a good ground.
    • If the resistance is more than 5 ohms, then test the circuit for an open, high resistance, or a faulty control module.
  14. Turn OFF the ignition.
  15. Remove the MAP sensor from the engine vacuum source. Leave the MAP sensor connected to the engine harness.
  16. Connect a Mityvac to the MAP sensor.
  17. Turn ON the ignition, with the engine OFF.
  18. Observe the MAP sensor pressure with the scan tool.
  19. Apply vacuum to the MAP sensor with the in 1 inch Hg increments until 15 inches Hg is reached. Each 1 inch Hg should decrease MAP sensor pressure by 3-4 kPa. Monitor the MAP sensor pressure to see if the decrease in pressure in consistent.
    • If decrease in pressure is not consistent then, test for intermittent and poor connections at the MAP sensor. If connections test OK, replace the MAP sensor.
  20. Apply vacuum with the until 20 inches Hg is reached. Observe the MAP sensor pressure for less than 34 kPa.
    • If more than 34 kPa, test for an intermittent and for a poor connection at the MAP sensor. If connections test OK, replace the MAP sensor.
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