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Home >> Chevrolet >> 2018 >> City Express LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 2.0L >> Diagnostic Information And Procedures >> DTC P0340 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the B23 Camshaft Position Sensor. It may take up to 2 minutes for all vehicle systems to power down.
  2. Test for less than 5 Ω between the low reference circuit terminal 2 and ground.
    • If 5 Ω or greater 
    1. Ignition OFF, disconnect the harness connector at the 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. Verify a test lamp illuminates between the ignition 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. Test for less than 2 Ω in the ignition 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 
      NOTE:

      The ignition circuit supplies voltage to other components. Make sure to test all circuits and components for a short to ground that share the ignition circuit.

    1. Ignition OFF, remove the test lamp and disconnect all components on the ignition circuit.
    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, replace the 23 Camshaft  Position Sensor.
    • Go to next step: If the test lamp illuminates 
  5. Test for 4.8 - 5.2 V between the signal 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 signal circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • 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.
    • 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 signal 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 
  6. Inspect for the conditions listed below:
    • Excessive play or looseness of the B23 Camshaft Position Sensor or the signal plate
    • Improper installation of the B23 Camshaft Position Sensor
    • Starter Motor
    • Foreign material passing between the B23 Camshaft Position Sensor and the signal plate
    • Damaged signal plate
    • Excessive air gap between the B23 Camshaft Position Sensor and the signal plate
    • Engine oil for debris
    • Timing chain, tensioner, and sprockets for wear or damage
    • If any of the conditions above are found, repair as necessary.
    • Go to next step: If all components test normal 
  7. Replace the B23 Camshaft Position Sensor.
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