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Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 24 (Engine Controls And Fuel - 2.8L (LWN) Diesel - Diagnostic Information And Procedures (1 Of 3)) >> Diagnostic Information and Procedures >> DTC P0106, P0107, or P0108 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
NOTE:

Circuit/System Verification must be performed before proceeding with Circuit/System Testing.

  1. Ignition/Vehicle & All vehicle systems - Off
  2. Verify the following conditions do not exist :
    • B65 Intake Manifold Pressure and Air Temperature Sensor
      • Leaking @ O-Ring/Missing/Visible Damage
      • Restricted - Water intrusion/Moisture/Ice
    • B75C Multifunction Intake Air Sensor - Contamination of the measuring element/Leaking/Visible Damage/Water intrusion
    • Fresh Air Inlet @ Barometric Pressure Sensor - Missing/Restricted/Visible Damage/Water intrusion
    • Q20 Intake Air Flow Valve
      • Leaking - Loose Clamps/Visible Damage
      • Restricted - Moisture/Ice
    • Air Cleaner Element - Dirty/Restricted
    • Intake Air Duct - Cracked/Loose Clamps/Restricted/Visible Damage
    • Intake Manifold - Cracked/Restricted/Visible Damage
    • Fastener @ Intake Manifold - Loose
    • Positive Crankcase Ventilation System
      • Leaking @ O-Ring - Missing/Visible Damage
      • Restricted - Moisture / Ice
      • Incorrect connection - Leaking/Restricted
    • If a condition exists 

      Repair or replace as necessary

    • Go to next step : If no condition exists 
    3. NOTE:

    It may take up to 2 min for all vehicle systems to power down before an accurate ground or low reference circuit continuity test can be performed.

  4. Disconnect the electrical connector : B65 Intake Manifold Pressure and Air Temperature Sensor
  5. Test for less than 5 ohms between the test points : Low Reference circuit terminal 1 & Ground
    • If 5 ohms or greater 
    1. Disconnect the appropriate electrical connector : K20 Engine Control Module
    2. Test for less than 2 ohms between the test points : Low Reference circuit terminal 1 @ Component harness & The other end of the circuit @ Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component : K20 Engine Control Module
    • Go to next step : If less than 5 ohms 
  6. Ignition - On / Vehicle - In Service Mode
  7. Test for 4.8 to 5.2 V between the test points : 5 V Reference circuit terminal 3 & Low Reference circuit terminal 1
    • If less than 4.8 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the appropriate electrical connector : K20 Engine Control Module
    3. Test for infinite resistance between the test points : 5 V Reference circuit terminal 3 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • Go to next step : If infinite resistance
    4. Test for less than 2 ohms between the test points : 5 V Reference circuit terminal 3 @ Component harness & The other end of the circuit @ Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component : K20 Engine Control Module
    • If greater than 5.2 V 
    1. Ignition/Vehicle - Off
    2. Disconnect the appropriate electrical connector : K20 Engine Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points : 5 V Reference circuit terminal 3 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • If less than 1 V - Replace the component : K20 Engine Control Module
    • Go to next step : If between 4.8 and 5.2 V 
  8. Verify the scan tool parameter : MAP Sensor = Greater than 4.7 V
    • If 4.7 V or less 
    1. Ignition/Vehicle - Off
    2. Disconnect the appropriate electrical connector : K20 Engine Control Module
    3. Test for infinite resistance between the test points : Signal circuit terminal 4 @ Component harness & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the component : K20 Engine Control Module
    • Go to next step : If greater than 4.7 V 
  9. Connect a 3 A fused jumper wire between the test points : Signal circuit terminal 4 & Low Reference circuit terminal 1
  10. Verify the scan tool parameter : MAP Sensor = Less than 0.2 V
    • If 0.2 V or greater 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the appropriate electrical connector : K20 Engine Control Module
    3. Ignition - On / Vehicle - In Service Mode
    4. Test for less than 1 V between the test points : Signal circuit terminal 4 @ Component harness & Ground
      • If 1 V or greater - Repair the short to voltage on the circuit.
      • Go to next step : If less than 1 V
    5. Ignition/Vehicle - Off
    6. Test for less than 2 ohms between the test points : Signal circuit terminal 4 @ Component harness & The other end of the circuit @ Control module harness
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Replace the component : K20 Engine Control Module
    • Go to next step : If less than 0.2 V 
  11. Test or replace the component : B65 Intake Manifold Pressure and Air Temperature Sensor
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