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 variant/trim >> Section 12 (Engine Controls And Fuel - 2.8L (LWN) Diesel - Diagnostic Information And Procedures (3 Of 3)) >> Diagnostic Information and Procedures >> Fuel Heater Diagnosis >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF.
  2. Disconnect the harness connector at the E11B Fuel Heater/Temperature Sensor.
  3. Test for less than 10 Ω between the fuel heater ground circuit terminal 7 and ground.
    • If 10 Ω or greater 

      Repair the open/high resistance in the circuit

    • Go to next step : If less than 10 Ω 
  4. Connect a test lamp between voltage supply circuit terminal 6 and ground.
  5. Ignition On.
  6. Command the Fuel Heater Relay On and Off with a scan tool. The test lamp should turn On and Off when commanded.
    • If the test lamp is always Off 
    1. Verify the fuse is good and there is voltage at the fuse.
      • If fuse is open, replace the fuse and repair the short to ground in the circuit.
      • Go to next step : If fuse is good and no voltage is present
    2. Ignition Off.
    3. Remove the KR22 Fuel Heater Relay from X50B Fuse Block-Underhood Auxiliary.
    4. Verify that a test lamp illuminates between the fuel heater voltage supply circuit terminal B1/87 and ground.
      • If the test lamp does not illuminate, repair the open/high resistance in the circuit.
      • Go to next step : If the test lamp illuminates
    5. Test for less than 2 ohms between the test points : Signal circuit terminal 6 @ Component harness & Terminal C3/30 @ KR22 Fuel Heater Relay
      • If greater than 2 Ω, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the KR22 Fuel Heater Relay.
    • If the test lamp is always On 
    1. Ignition Off.
    2. Remove the KR22 Fuel Heater Relay from X50B Fuse Block-Underhood Auxiliary.
    3. Ignition On.
    4. Test for less then 1 V between the fuel heater voltage supply circuit terminal 6 and ground.
      • If 1 V or greater, repair the short to voltage in the circuit.
      • If less than 1 V, replace the KR22 Fuel Heater Relay.
    • Go to next step : If the test lamp turns On and Off 
  7. Replace the E11B Fuel Heater/Temperature Sensor.
scientia non olet · About LEMON Manuals