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Home >> Pontiac >> 2008 >> Torrent GXP, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 150 (Engine Controls And Fuel - 3.6L - DTC P0335 To P2105) >> DTC P0627, P0628, or P0629 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
  1. Ignition OFF, disconnect the fuel pump relay.
  2. Connect a test lamp between the control circuit terminal 86 of the fuel pump relay and ground.
  3. Ignition ON, command the fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF as commanded.
    • If the test lamp remains OFF all the time, test the control circuit for a short to ground or an open/high resistance. If circuit/connections test normal, replace the ECM.
    • If the test lamp remains ON all the time, test the control circuit for a short to voltage. If circuit/connections test normal, replace the ECM.
  4. Ignition OFF, connect a test lamp between the fuel pump relay control circuit terminal 86 and the ground circuit terminal 85 of the fuel pump relay.
  5. Ignition ON, command the fuel pump ON and OFF with a scan tool. The test lamp should turn ON and OFF as commanded.
    • If the test lamp does not turn ON when commanded, repair the open/high resistance in ground circuit of the fuel pump relay.
  6. Ignition ON, test for 2-3 V on the control circuit terminal 86 of the fuel pump relay.
    • If not within the specified range, replace the ECM.
  7. If all circuits/connections test normal, test or replace the fuel pump relay.
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