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Home >> Chevrolet >> 2008 >> Optra5 LS, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 2.0L (Diesel) >> Diagnostic Information and Procedures >> Ignition Relay Diagnosis >> Circuit/System Testing

Circuit/System Testing

  1. Ignition OFF, disconnect the EC ignition relay.
  2. Ignition ON, verify a test lamp illuminates between the relay coil ignition 1 voltage circuit terminal 85 and ground.
    • If the test lamp does not illuminate, repair the relay coil ignition 1 voltage circuit for a short to ground or an open/high resistance. Replace the fuse if necessary.
  3. Ignition OFF, connect a test lamp between the relay coil control circuit terminal 86 and the relay coil ignition 1 voltage circuit terminal 85.
    • If the test lamp is always ON, test the control circuit for a short to ground. If the circuit tests normal, replace the ECM.
  4. Ignition ON. The test lamp should turn ON.
    • If the test lamp is always OFF, test the control circuit for a short to voltage or an open/high resistance. If circuit tests normal, replace the ECM.
    5. IMPORTANT: The ignition 1 voltage circuit is between the EC ignition relay and the ECM. The ignition 1 voltage is a feedback circuit.
  5. Install a 20A fused jumper wire between the relay switch B+ circuit terminal 30 and the relay switch ignition 1 voltage circuit terminal 87.
  6. Attempt to start the engine. The engine should start.
    • If the engine does not start, test the ignition 1 voltage circuit between the EC ignition relay and the ECM for a short to ground or for an open/high resistance. If the circuit tests normal, replace the ECM.
  7. If all circuits test normal, test or replace the EC ignition relay.
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