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Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 92 (Engine Controls And Fuel - 2.8L (LWN) Diesel - Diagnostic Information And Procedures (1 Of 3)) >> Diagnostic Information and Procedures >> DTC P0097-P0099 or P00F4-P00F6 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
    NOTE:

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

  1. Ignition/Vehicle & All vehicle systems - Off 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.
  2. Disconnect the electrical connector: B75C Multifunction Intake Air Sensor
  3. Test for less than 5 ohms between the test points: Low Reference circuit terminal 3 & Ground
    • If 5 ohms or greater 
    1. Disconnect the electrical connector: X1 @ K20 Engine Control Module
    2. Test for less than 2 ohms between the test points: Low Reference circuit terminal 3 @ Component harness & The other end of the circuit @ K20 Engine Control Module
      • 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 
  4. Verify the scan tool parameter: Intake Air Humidity Sensor = Less than 1%
    • If 1% or greater 
    1. Ignition/Vehicle - Off
    2. Disconnect the electrical connector: X3 @ K20 Engine Control Module
    3. Test for infinite resistance between the test points: Signal circuit terminal 8 & 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 less than 1% 
  5. Ignition/Vehicle - Off
  6. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 8 @ Component harness & Low Reference circuit terminal 3
  7. Ignition - On / Vehicle - In Service Mode
  8. Verify the scan tool parameter: Intake Air Humidity Sensor = Greater than 99%
    • If less than 100% 
      NOTE:

      Internal control module or component damage may occur if the circuit shorts to B+.

    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the electrical connector: X3 @ 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 8 & 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 8 & The other end of the circuit @ K20 Engine Control Module
      • 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 99% 
  9. Test or replace the component: B75C Multifunction Intake Air Sensor
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