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Home >> Cadillac >> 2008 >> STS V >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 4.4L - DTC P0010 To DTC P0158 >> DTC P0101 or P1101 >> Circuit/System Testing

Circuit/System Testing

IMPORTANT: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
  1. Visually and physically inspect the by-pass valve and cable for any of the following conditions:
    • A binding or sticking when opening or closing
    • An incorrectly adjusted cable
  2. Verify the integrity of the entire supercharger air induction system by inspecting for the following conditions:
    • A restricted or collapsed air intake duct
    • A misaligned or damaged air intake duct
    • A dirty or deteriorating air filter element
    • Any objects blocking the air inlet probe of the MAF/IAT sensor
    • Any contamination or debris on the sensing elements in the probe of the MAF/IAT sensor
    • Any water intrusion in the induction system
    • Any unmetered air downstream of the MAF/IAT sensor
    • An intake manifold leak
    • Any snow or ice build up at the air cleaner or MAF/IAT sensor
    • A SCIAP sensor vacuum hose that is missing or damaged
    • A MAP sensor vacuum hose that is missing or damaged
  3. Ignition OFF, disconnect the harness connector at the MAF sensor.
  4. Ignition OFF for 90 seconds, test for less than 5 ohms between the ground circuit terminal B and ground.
    • If greater than the specified range, test the ground circuit for an open/high resistance.
  5. Ignition ON, test for 4.8-5.2 volts between the MAF sensor signal circuit terminal A and ground.
    • If less than the specified range, test the MAF sensor signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the MAF sensor signal circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  6. Ignition ON, verify that a test lamp illuminates between the MAF sensor ignition 1 voltage circuit terminal C and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance.
  7. Ignition OFF, connect the read lead of J 38522  to the signal circuit terminal A at the MAF/IAT sensor harness connector. Connect the battery voltage supply to B+, and ground the black lead.
  8. Set the J 38522  signal to 5 volts, the Frequency to 5K, and the Duty Cycle to Normal.
  9. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,025 Hz.
    • If the MAF Sensor parameter is not within the specified range, replace the ECM.
    • If all other circuits test normal, test or replace the MAF Sensor.
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