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Home >> Chevrolet >> 2018 >> Equinox L >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 13 (Engine Controls And Fuel - 1.6L (LH7) Diesel - Diagnostic Information And Procedures (P0016 - P049D)) >> Diagnostic Information And Procedures >> DTC P0101: Mass Air Flow (MAF) Sensor Performance >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
NOTE:
  • You must perform the Circuit/System Verification before proceeding with the Circuit/System Testing.
  • You must perform the Diagnostic Repair Verification after completing the Circuit/System Testing.
  1. Verify none of the following conditions exist:
    • A dirty or deteriorating air filter element
    • A leaking, loose, disconnected, or cracked positive crankcase ventilation (PCV) valve, pipe, or seal
    • A loose or disconnected charge air cooler hose or pipe
    • A restricted or collapsed air intake duct
    • A misaligned or damaged air intake duct
    • Any objects blocking the air inlet probe of the Mass Air Flow/Intake Air Temperature sensor
    • Any contamination or debris on the sensing elements in the probe of the Mass Air Flow/Intake Air Temperature sensor
    • A cracked or damaged mass air flow sensor housing
    • Any water intrusion in the induction system
    • Any snow or ice build-up at the air cleaner, mass air flow sensor, charge air cooler, or manifold absolute pressure sensor, in cold climates
    • An intake manifold leak
    • A manifold absolute pressure sensor seal that is leaking, missing, or damaged
    • An Intake Manifold Resonator with a leaking seal, or a cracked or broken housing
    • A restriction in the exhaust system. Refer to Restricted Exhaust .
    • A leak in the exhaust system. Refer to Exhaust Leakage .
    • If a condition exists 

      Repair as necessary.

    • Go to next step: If no condition exists 
  2. Engine idling at operating temperature, command the EGR Valve to 0% with a scan tool.
  3. Verify the Induction System Leak Indication parameter is between 0.75:1 and 1.25:1 for at least 10 s.
    • If not stable or between 0.75:1 and 1.25:1 after 10 s 
    1. Verify the Q14 Exhaust Gas Recirculation Valve is in the closed position, by visual inspection. Refer to Exhaust Gas Recirculation Valve Replacement .
      • If the Q14 Exhaust Gas Recirculation Valve is not closed.

        Replace the Q14 Exhaust Gas Recirculation Valve and gaskets.

      • If the Q14 Exhaust Gas Recirculation Valve is closed.
    2. Test the charge air cooler system and air inlet system for leaks. Perform the Charge Air Cooler Diagnosis (Leak Test)Charge Air Cooler Diagnosis (Smoke Test) .
      • If a condition exists.

        Repair or replace the component as necessary.

    • Go to next step: If stable and between 0.75:1 and 1.25:1 after 10 s 
  4. Ignition Off and all systems Off. Disconnect the harness connector at the B75C Multifunction Intake Air Sensor.
  5. Test for less than 5 Ω between the ground circuit terminal 7 and ground.
    • If 5 Ω or greater 
    1. Disconnect the sensor chassis ground.
    2. Test for less than 2 Ω in the ground circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, repair the open/high resistance in the chassis ground connection.
    • Go to next step: If less than 5 Ω 
  6. Ignition On, verify a test lamp illuminates between the voltage supply circuit terminal 5 and ground.
    • If the test lamp does not illuminate 
    1. Ignition Off, remove the test lamp, and disconnect harness connector X2 at the K20 Engine Control Module.
    2. Test for infinite resistance between the voltage supply circuit, and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance.
    3. Test for less than 2 Ω in the voltage supply circuit, end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • Go to next step: If the test lamp illuminates 
  7. Ignition On, test for 4.8 - 5.2 V between the signal circuit terminal 6 and ground.
    • If less than 4.8 V 
    1. Ignition Off, disconnect the harness connector X1 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 2 Ω in the signal circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • If greater than 5.2 V 
      NOTE:

      If the signal circuit is shorted to a voltage the engine control module or the sensor may be damaged.

    1. Ignition Off, disconnect harness connector X1 at the K20 Engine Control Module.
    2. Ignition On.
    3. Test for less than 1 V between the signal circuit terminal 6 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step: If between 4.8 - 5.2 V 
  8. 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+
  9. Set the EL-38522-A  Variable Signal Generator to the following specifications.
    • Signal switch to 5 V
    • Duty Cycle switch to 50% (Normal)
    • Frequency switch to 5 KHz
  10. Engine idling.
  11. Verify the scan tool MAF Sensor parameter is between 4, 950 - 5, 050 Hz.
    • If not between 4, 950 - 5, 050 Hz. 

      Replace the K20 Engine Control Module.

    • Go to next step: If between 4, 950 - 5, 050 Hz. 
  12. Replace the B75C Multifunction Intake Air sensor.
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