LEMON Manuals: Even more car manuals for everyone
Home >> Chevrolet >> 2017 >> Spark LT, Automatic CVT Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 81 (Engine Controls And Fuel - 1.6L (LWC) - DTC P0243 To DTC P2635 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> DTC P0451-P0454 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2019 Buick Cascada, 2018 Buick Cascada, and 2017 Buick Cascada. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, all vehicle systems OFF, it may take up to 2 min for all vehicle systems to power down. Disconnect the harness connector at the B150 Fuel Tank Pressure Sensor.
  2. Test for less than 5 Ω of resistance between the low reference circuit terminal 2 and ground.
    • If 5 Ω or greater 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for less than 2 Ω in the low reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • Go to next step: If less than 5 Ω 
  3. Ignition ON.
  4. Test for 4.8 - 5.2 V between the 5 V reference circuit terminal 3 and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the 5 V reference circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the 5 V reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K20 Engine Control Module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON.
    2. Test for less than 1 V between the 5 V reference circuit and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step: If between 4.8 - 5.2 V 
  5. Verify the scan tool Fuel Tank Pressure parameter is less than 0.2 V.
    • If 0.2 V or greater 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module, ignition ON
    2. Test for less than 1 V between the signal circuit terminal 1 and ground.
    • If 1 V or greater, repair the short to voltage on the circuit.
    • If less than 1 V, replace the K20 Engine Control Module.
    • Go to next step: If less than 0.2 V 
  6. Install a 3 A fused jumper wire between the signal circuit terminal 1 and the 5 V reference circuit terminal 3.
  7. Verify the scan tool Fuel Tank Pressure sensor parameter is greater than 4.7 V.
    • If 4.7 V or less 
    1. Ignition OFF, disconnect the harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between the signal circuit terminal 1 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • Go to next step: If infinite resistance
    3. Test for less than 2 Ω in the signal circuit end to end.
    • If 2 Ω or greater, repair the open/high resistance in the circuit.
    • If less than 2 Ω, replace the K20 Engine Control Module.
    • Go to next step: If greater than 4.7 V 
  8. Test or replace the B150 Fuel Tank Pressure Sensor.
scientia non olet · About LEMON Manuals