LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different car >> Section 94 (Engine Controls And Fuel - 2.8L (LWN) Diesel - Diagnostic Information And Procedures (3 Of 3)) >> Diagnostic Information and Procedures >> DTC P2199 >> 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. Verify the following conditions do not exist:
    • B75C Multifunction Intake Air Sensor - Contamination of the measuring element/Cracked/Visible Damage/Water intrusion
    • Intake Air Duct - Cracked/Incorrect connection/Restricted/Visible Damage
    • If a condition exists 

      Repair or replace as necessary.

    • Go to next step: If no condition exists 
  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the electrical connector: B75C Multifunction Intake Air Sensor
  3. Test for less than 5 ohms between the test points: Ground circuit terminal 7 & Ground
    • If 5 ohms or greater 
    1. Disconnect the ground connection: 107
    2. Test for less than 2 ohms between the test points: Ground circuit terminal 4 @ Component harness & Ground terminal G107
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Repair the open/high resistance in the ground connection.
    • Go to next step: If less than 5 ohms 
  4. Test for less than 5 ohms between the test points: Low Reference circuit terminal 3 & Ground
    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 
  5. Ignition - On / Vehicle - In Service Mode
  6. Verify a test lamp turns On between the test points: Ignition circuit terminal 5 & Ground
    • If the test lamp does not turn On and the circuit fuse is OK 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Test for less than 2 ohms between the test points: Ignition circuit terminal 5 @ Control module harness & Output terminal @ F11UA Fuse
      • If 2 ohms or greater - Repair the open/high resistance in the circuit.
      • If less than 2 ohms - Verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not turn On and the circuit fuse is open 
    1. Ignition/Vehicle - Off
    2. Replace the component: F11UA Fuse
    3. Ignition - On / Vehicle - In Service Mode
    4. Verify the fuse does not open.
      • If the fuse opens and there are components connected to the circuit - Disconnect a component and repeat procedure starting at step 5. 1
      • If the fuse opens with all components disconnected from the circuit - Repair the short to ground on the circuit.
      • If the fuse does not open after disconnecting a component from the circuit - Replace the component disconnected last.
      • Go to next step: If the fuse does not open.
      5. NOTE:

      It may be necessary to use a scan tool control function to operate a component.

    5. Operate the component: Each component on the circuit - One at a time

      Verify the fuse does not open when any of the components are activated.

      • If the fuse opens - Replace the component that caused the fuse to open when activated.
      • Go to next step: If the fuse does not open.
    6. All OK.
    • Go to next step: If the test lamp turns On 
  7. Verify the scan tool parameter: IAT Sensor 1 = Colder than -39°C (-38°F)
    • If -39°C (-38°F) or warmer 
    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 1 @ 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 colder than -39°C (-38°F) 
  8. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 1 & Low Reference circuit terminal 3
  9. Verify the scan tool parameter: IAT Sensor 1 = Warmer than 149°C (300°F)
    • If 149°C (300°F) or colder 
    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 1 @ 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 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 warmer than 149°C (300°F) 
  10. Verify the scan tool parameter: Intake Air Humidity Sensor = Less than 1%
    • If 1% or greater 
    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 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% 
  11. Ignition/Vehicle - Off
  12. Connect a 3 A fused jumper wire between the test points: Signal circuit terminal 8 @ Component harness & Low Reference circuit terminal 3
  13. Ignition - On / Vehicle - In Service Mode
  14. Verify the scan tool parameter: Intake Air Humidity Sensor = Greater than 99%
    • If less than 99% 
      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 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 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 @ 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 99% 
  15. Test or replace the component: B75C Multifunction Intake Air Sensor
scientia non olet · About LEMON Manuals