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Home >> Chevrolet >> 2017 >> City Express LS >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 2.0L >> Diagnostic Information And Procedures >> DTC P2100 or P2103 >> Circuit/System Testing
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Circuit/System Testing

  1. Ignition Off, disconnect harness connector X1 at the K20 Engine Control Module.
  2. Ignition On.
  3. Test for B+ between circuit terminal E2-X1 and ground, with a DMM.
      NOTE:

      Fuse F52UA may be labeled as F24 ETC.

    • If less than B+ and the circuit fuse F52UA is good 
    1. Ignition OFF.
    2. Disconnect the harness connector X4 at the X50A Fuse Block - Underhood.
    3. Test the relay control circuit for infinite resistance between K20 circuit terminal E2-X1 and ground.
      • If less than infinite resistance, repair the short to ground in the relay control circuit.
      • If infinite resistance
    4. Test for less than 2 Ω between the relay control circuit terminal E2-X1 and the other end of the circuit at the X50A harness connector X4.
      • If 2 Ω or greater, repair the open/high resistance in the control circuit.
      • If less than 2 Ω, test or replace the X50A Fuse Block - Underhood.
      NOTE:

      Fuse F52UA may be labeled as F24 ETC.

    • If less than B+ and the circuit fuse is open 
    1. Ignition Off.
    2. Disconnect the harness connector X4 at the X50A Fuse Block - Underhood.
    3. Test for infinite resistance between the KR164 Throttle Body Relay B+ switch circuit terminal H3-X1 and ground.
      • If less than infinite resistance, repair the short to ground in the relay switch circuit.
      • If infinite resistance
    4. Connect the harness connector X4 at the X50A Fuse Block - Underhood.
    5. Replace the fuse F52UA, ignition On.
    6. Verify the fuse does not open.
      • If fuse F52UA is open

        Test or replace the X50A Fuse Block - Underhood

      • If fuse F52UA is not open.
    7. Ignition Off, connect harness connector X1 at the K20 Engine Control Module.
    8. Ignition On.
    9. Verify the fuse does not open.
      • If fuse F52UA is open

        Test or replace the K20 Engine Control Module

      • If fuse F52UA is not open.
    10. Refer to Testing for Intermittent Conditions and Poor Connections
    • Go to next step: If B+ 
  4. Verify a test lamp does Not illuminate between the KR164 Throttle Body Relay B+ switch circuit terminal H3-X1 and ground.
    • If the test lamp illuminates 
    1. Ignition Off, remove the test lamp.
    2. Disconnect the harness connector X4 at the X50A Fuse Block - Underhood.
    3. Ignition On, test for less than 1 V between the switch circuit terminal H3-X1 and ground.
      • If 1 V or greater, repair the short to voltage in the circuit.
      • If less than 1 V, replace the X50A Fuse Block - Underhood
    • Go to next step: If the test lamp does not illuminate 
  5. Connect a 3 A fused jumper wire between KR164 Throttle Body Relay control circuit terminal E2-X1 and ground.
  6. Ignition On.
  7. Verify a test lamp illuminates between the KR164 Throttle Body Relay B+ switch circuit terminal H3-X1 and ground.
    • If the test lamp does not illuminate 
    1. Ignition Off, remove the test lamp and the fused jumper wire.
    2. Disconnect the harness connector X4 at the X50A Fuse Block - Underhood.
    3. Test for less than 2 Ω in the relay switch circuit, end to end.
      • If 2 Ω or greater, repair open/high resistance in the relay switch circuit.
      • If less than 2 Ω, replace the X50A Fuse Block - Underhood
    • Go to next step: If the test lamp illuminates 
  8. Replace the K20 Engine Control Module.
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