LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2017 >> City Express LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 2.0L >> Diagnostic Information And Procedures >> DTC P0443 >> Circuit/System Testing
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Circuit/System Testing

  1. Ignition OFF, disconnect the harness connector at the Q 12 Evaporative Emission Purge Solenoid Valve.
  2. Ignition ON. Verify that a test lamp illuminates between the ignition voltage circuit terminal 1 and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Ignition OFF, remove the test lamp.
    2. Disconnect the Intelligent Power Distribution Module (IPDM) harness connector.
    3. Test for less than 2 Ω in the circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Ignition OFF, remove the test lamp.
    2. Test for infinite resistance between the ignition circuit and ground
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, test all components connected to the ignition voltage circuit for a short and replace as necessary.
    • Go to next step: If the test lamp illuminates 
  3. Verify that a test lamp does not illuminate between the ignition circuit terminal 1 and the control circuit terminal 2.
    • If the test lamp illuminates 
    1. Ignition OFF, remove the test lamp, disconnect the harness connector at the K 20 Engine Control Module.
    2. Test for infinite resistance between the control circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K 20 Engine Control Module.
    • Go to next step: If the test lamp does not illuminate 
  4. Remove the test lamp.
  5. Ignition OFF.
  6. Reconnect harness connectors.
  7. Start engine.
  8. Perform Q 12 EVAP Emission Purge Solenoid Valve test using a scan tool. Check that engine speed varies according to the valve opening.
    • If engine speed does not vary.
    1. Ignition OFF, disconnect EVAP purge hoses connected to Q 12 EVAP Emission Purge Solenoid Valve.
    2. Start engine.
    3. Perform the Purge Volume Control Valve test using scan tool.
    4. Check for air passage through the Q 12 EVAP Emission Purge Solenoid Valve when commanded to 100% with scan tool and no air passage when commanded to 0%.
      • If test fails, replace the Q 12 EVAP Emission Purge Solenoid Valve.
    • Go to next step: If test passes 
  9. Check Q 13 EVAP Emission Vent Solenoid Valve for internal rust or corrosion
    • If rust or corrosion is present, replace Q 13 EVAP Emission Vent Solenoid Valve.
    • Go to next step: If No rust or corrosion in Q 13 EVAP Emission Vent Solenoid Valve 
  10. Check EVAP canister.
    1. Weigh EVAP canister with the Q 13 EVAP Emission Vent Solenoid Valve and B 150 Fuel Tank Pressure Sensor attached. Weight should be less than 2.1 kg (4.6 lb). 
    • If more than 2.1 kg (4.6 lb). 
    • Replace EVAP canister.
    • Go to next step: If less than 2.1 kg (4.6 lb) 
  11. Check EVAP hoses between EVAP canister and vehicle frame for clogging or poor connection
    • If hoses are damaged, replace hoses.
    • If hoses are not damaged
  12. All OK.
scientia non olet · About LEMON Manuals