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Home >> Chevrolet >> 2018 >> Spark LT, Automatic CVT Trans >> Repair and Diagnosis >> External Pages >> Different car >> Section 35 (Engine Controls And Fuel - 1.4L (LV7) - DTC P0351 To DTC P2544 And Diagnostic Information And Procedures) >> Diagnostic Information and Procedures >> DTC P0685-P0687, P0689, P0690, or P1682: Engine Controls Ignition Relay/Ignition 1 Switch Circuit 2 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2017 Chevrolet Spark. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:

You must perform the Circuit/System Verification before proceeding with Circuit/System Testing unless sent here from Engine Cranks But Does Not Run.

  1. Ignition OFF, disconnect the KR75 Engine Controls Ignition Relay.
  2. Verify that a test lamp illuminates between ground and the B+ terminals listed below:
    • Terminal 86
    • Terminal 30
    • If the test lamp does not illuminate 

      Replace the X50A Fuse Block - Underhood.

    • If the test lamp illuminates 
      NOTE:
      • High resistance in the circuit/underhood fuse block for either the KR75 Engine Controls Ignition Relay or the KR73 Ignition Main Relay can cause DTC P1682 to set
      • A short to voltage on any of the circuits supplied by the engine controls ignition relay can cause DTC P0690 to set
  3. Ignition ON.
  4. Verify the test lamp does not illuminate between the ignition voltage circuit terminal 87 and ground.
    • If the test lamp illuminates 
    1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module.
    2. Ignition ON.
    3. Test for less than 1 V between ground and connector terminal 16.
      • If 1 V or greater, repair the short to voltage in the circuit.
      • If less than 1 V, replace the K20 Engine Control Module.
    • If the test lamp does not illuminate 
  5. Ignition OFF, connect a 20 A fused jumper wire between the B+ circuit terminal 30 and the ignition voltage circuit terminal 87, ignition ON.
  6. Verify the scan tool Engine Controls Ignition Relay Feedback Signal parameter displays B+.
    • If B+ is not displayed 
    1. Ignition OFF, disconnect the X1 harness connector at the K20 Engine Control Module
    2. Test for less than 2 Ω in the relay switch ignition voltage circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω
    3. Test for infinite resistance between the relay switch ignition voltage circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • If B+ is displayed 
  7. Ignition OFF, connect a DMM, set to the diode setting, between the control circuit terminal 85 and ground.
  8. Verify the DMM displays OL.
    • If OL is not displayed 
    1. Disconnect the X1 harness connector at the K20 Engine Control Module.
    2. Test for infinite resistance between ground and the relay control circuit.
      • If less than infinite resistance, repair the short to ground in the circuit.
      • If infinite resistance, replace the K20 Engine Control Module.
    • If OL is displayed 
  9. Ignition ON.
  10. Verify the DMM displays less than 1 V.
    • If 1 V or greater 
    1. Ignition OFF, disconnect the X1 connector at the K20 Engine Control Module.
    2. Ignition ON.
    3. Test for less than 1 V on the relay control circuit.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    4. Test for less than 2 Ω in the control 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 less than 1 V 
  11. Test or replace the KR75 Engine Controls Ignition Relay.
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