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Home >> Chevrolet >> 2006 >> Epica LT >> Repair and Diagnosis >> Engine Performance >> System >> Engine Control System - 2.5L (LBK) - DTC P0230 To DTC P0501 >> DTCP0230 or P1231 >> Circuit/System Testing

Circuit/System Testing

  1. Ignition OFF, remove the fuel pump relay from the underhood fuse block assembly.
  2. Ignition ON, load test for battery voltage between the ignition 1 voltage circuit of the fuel pump relay and ground.
    • If less than B+, repair the ignition 1 voltage circuit of the fuel pump relay for a short to ground or an open/high resistance.
  3. With the ignition OFF, connect a test lamp between the control circuit and the ignition 1 voltage circuit of the fuel pump relay.
  4. With the ignition ON, use a scan tool to command the fuel pump relay ON. The test lamp should turn ON for about 3-5 seconds and then turn OFF.
    • If the test lamp remains ON all the time, test for a short to ground on the control circuit. If circuit/connections test normal, replace the ECM.
    • If the test lamp remains OFF all the time, test for a short to voltage or an open/high resistance on the control circuit. If circuit/connections test normal, replace the ECM.
  5. If all circuits/connections test normal, test or replace the fuel pump relay.
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