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Home >> Buick >> 2015 >> Regal GS, AWD >> Repair and Diagnosis >> Engine Performance >> Testing & Diagnosis >> Engine Controls And Fuel - 2.0L (LTG) - DTC P0010 To DTC P0333 >> Diagnostic Information and Procedures >> DTC P0101: Mass Air Flow (MAF) Sensor >> Circuit/System Testing

Circuit/System Testing

NOTE:

You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

  1. Verify the integrity of the entire air induction system by verifying that none of the following conditions exist:
    • Any damaged components
    • Improper operation of turbocharger wastegate actuator or bypass valve; where equipped
    • Improperly installed components
    • Collapsed, restricted, or damaged components
    • Loose clamps, cracks, or other damage
    • An air flow restriction
    • Restricted air filter
    • Splits, kinks, leaks, or improper connections at the vacuum hoses
    • Vacuum leaks at the intake manifold, MAP sensor, and throttle body
    • Water intrusion
    • Any snow or ice buildup, in cold climates
    • Contamination of the Mass Air Flow sensor element
    • If a condition is found 

      Repair or replace component as appropriate.

    • If no condition is found 
  2. Ignition OFF, disconnect the harness connector at the B75C Multifunction Intake Air sensor.
  3. Test for less than 2Ω between the ground circuit terminal 7 and ground.
    • If 2Ω or greater 
    1. Ignition OFF.
    2. Test for less than 2Ω in the ground circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, repair the open/high resistance in the ground connection.
    • If less than 2Ω 
  4. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal 5 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit.
    2. Test for less than 2Ω in the ignition voltage circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, remove the test lamp and remove the fuse for the ignition voltage circuit.
    2. Test for infinite resistance between the ignition voltage circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, test all components connected to the ignition circuit, replace as necessary.
    • If a test lamp illuminates 
  5. Ignition ON, test for 4.8-5.2 volts between the signal circuit terminal 6 and ground.
    • If less than 4.8V 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2Ω in the signal circuit end to end.
      • If 2Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2Ω, replace the K20 Engine Control Module.
    • If greater than 5.2V 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Ignition ON, test for less than 1V between the signal circuit and ground.
      • If 1V or greater, repair the short to voltage on the circuit.
      • If less than 1V, replace the K20 Engine Control Module.
    • If between 4.8-5.2V 
  6. Determine if EL-38522-A   Variable Signal Generator or equivalent is available.
    • EL-38522-A, Variable Signal Generator; or equivalent is not available 
    1. Test or replace the B75C Multifunction Intake Air sensor.
    2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the freeze frame/failure records data.
    3. Verify the DTC does not set.
      • If the DTC sets 

        Replace the K20 Engine Control Module.

      • If no DTCs set 
    4. All OK.
    • EL-38522-A, Variable Signal Generator; or equivalent is available 
  7. Ignition OFF, connect the leads of the EL-38522-A   Variable Signal Generator as follows:
    • Red lead to the signal circuit terminal 6 at the harness connector
    • Black leads to ground
    • Battery voltage supply lead to B+
  8. Set the EL-38522-A   Variable Signal Generator to the following specifications.
    • Signal switch to 5V
    • Frequency switch to 5kHz
    • Duty Cycle switch to 50% (Normal)
  9. Engine idling, observe the scan tool MAF Sensor parameter. The scan tool MAF Sensor parameter should be between 4,950-5,050 Hz.
    • If not between 4,950-5,050 Hz. 

      Replace the K20 Engine Control Module.

    • If between 4,950-5,050 Hz. 
  10. Test or replace the B75C Multifunction Intake Air sensor.