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Home >> Chevrolet >> 2020 >> Express 2500 LS, 6.0L Eng VIN G >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 20 (Engine Controls And Fuel - 4.3L (LV1) - Diagnostic Information And Procedures (1 Of 2)) >> Diagnostic Information and Procedures >> DTC P0030-P0032, P0036-P0038, P0050-P0054, P0056-P0060, P0135, P0141, P0155, or P0161 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition/Vehicle & All vehicle systems - Off
  2. Disconnect the appropriate electrical connector : B52 Heated Oxygen Sensor
  3. Ignition - On / Vehicle - In Service Mode
  4. Verify a test lamp turns On between the test points : Ignition circuit terminal 2 & 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 2 & Output terminal @ 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 & Remove - Test lamp
    2. Test for infinite resistance between the test points : Ignition circuit terminal 2 & Ground
      • If less than infinite resistance - Repair the short to ground on the circuit.
      • If infinite resistance - Replace the appropriate component : B52 Heated Oxygen Sensor
    • Go to next step : If the test lamp turns On 
  5. Verify a test lamp does not turn On between the test points : Control circuit terminal 1 & B+
    • If the test lamp turns On 
    1. Ignition/Vehicle - Off & Remove - Test lamp
    2. Disconnect the appropriate electrical connector : K20 Engine Control Module
    3. Test for infinite resistance between the test points : Control 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 the test lamp does not turn On 
  6. Remove - Test Lamp
  7. Perform the scan tool control function : HO2S Heater Bank 1, 2 Sensor 1, 2 - On

    Verify the scan tool parameter : HO2S Heater Control Circuit High Voltage Test Status Bank 1, 2 Sensor 1, 2 = OK

    • If not the specified state 
    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 : Control circuit terminal 1 @ 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 the specified state 
    8. NOTE:
    • As little as 10 ohms of resistance in a circuit may cause a DTC to set.
    • Performing this test may set additional DTCs.
  8. Connect a 3 A fused jumper wire between the test points : Control circuit terminal 1 & Ignition circuit terminal 2
  9. Perform the scan tool control function : HO2S Heater Bank 1, 2 Sensor 1, 2 - On

    Verify the scan tool parameter : HO2S Heater Control Circuit High Voltage Test Status Bank 1, 2 Sensor 1, 2 = Malfunction

    • If not the specified state 
    1. Ignition/Vehicle - Off & Remove - Jumper wire(s)
    2. Disconnect the appropriate electrical connector : K20 Engine Control Module
    3. Test for less than 2 ohms between the test points : Control 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 the specified state 
  10. Test or replace the component : B52 Heated Oxygen Sensor
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