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Home >> Cadillac >> 2018 >> Escalade Base, 4WD >> Repair and Diagnosis >> External Pages >> Different car >> Section 5 (Engine Controls And Fuel - 6.0L (L96) - DTC P0010 To DTC P0341) >> Diagnostic Information And Procedures >> DTC P0102 Or P0103: Mass Air Flow (MAF) Sensor Circuit >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2018 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.
NOTE: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
  1. Ignition OFF and all systems OFF. Disconnect the harness connector at the B75C Multifunction Intake Air Sensor.
  2. Test for less than 2 Ω between the ground circuit terminal 7 and ground.
    • If 2 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 2 Ω 
  3. Ignition ON.
  4. 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 2 Ω in the ignition voltage circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, 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.
      • Go to next step: If infinite resistance
    3. Test for greater than 2 Ω between the ignition voltage circuit terminal 5 and ground.
      • If less than 2 Ω, repair the short to ground on the circuit.
      • If greater than 2 Ω, test all the components connected to the circuit and repair or replace as necessary.
    • Go to next step: If a test lamp illuminates 
  5. 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 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.
      • Go to next step: 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 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the signal circuit 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 
  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.

      • Go to next step: If no DTCs set 
    4. All OK.
    • Go to next step: 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 listed below:
    • 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 specifications listed below:
    • Signal switch to 5 V
    • Frequency switch to 5 kHz
    • Duty Cycle switch to 50% (Normal)
  9. Engine idling.
  10. Verify the scan tool MAF Sensor parameter is between 4, 950 - 5, 050 Hz.
    • If not 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. 
  11. Test or replace the B75C Multifunction Intake Air Sensor.
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