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Home >> Buick >> 2008 >> Allure CXL >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 7 (Engine Control System & Fuel System - 3.6L - DTC P0008 To DTC P0333) >> DTC P0201, P0202, P0203, P0204, P0205, P0206, P0261, P0262, P0264, P0265, P0267, P0268, P0270, P0271, P0273, P0274, P0276, or P0277 >> Circuit/System Testing

Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
  1. Ignition OFF, disconnect the fuel injector multi-way harness connector C109.
    2. IMPORTANT: Testing for steps 2 through 4 is performed on the ECM side of the multi-way harness connector.
  2. Ignition ON, load test for B+ between the appropriate ignition voltage supply circuit and ground.
    • If less than the specified range, repair the ignition voltage circuit for a short to ground, or an open/high resistance. Replace the fuse if necessary.
  3. Test for 2.6-4.6 volts between the appropriate fuel injector control circuit and ground
    • If less than the specified range, test the control circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the ECM.
    • If greater than the specified range, test the control circuit for a short to voltage. If the circuit tests normal, replace the ECM.
  4. Probe the appropriate fuel injector control circuit with a test lamp connected to B+. Engine cranking, verify the test lamp flashes.
    • If the test lamp remains OFF, test the control circuit for a high resistance. If the circuit/connections test normal, replace the ECM.
    5. IMPORTANT: Testing for steps 5 and 6 is performed on the fuel injector side of the multi-way harness connector. It may be necessary to remove the upper intake manifold to isolate the condition. Refer to Upper Intake Manifold Replacement .
  5. Ignition OFF, test for OL ohms between the appropriate ignition voltage circuit and ground.
    • If less than the specified range, repair the ignition voltage, or control circuit, for a short to ground. If the circuits/connections test normal, test or replace the appropriate fuel injector(s).
  6. Test for 12-16 ohms between the appropriate ignition voltage circuit and each fuel injector control circuit.
    • If less than the specified range, test for a short between the control circuit and the ignition voltage circuit. If the circuits/connections test normal, test or replace the appropriate fuel injector(s).
    • If greater than the specified range, test the ignition voltage, and fuel injector control circuit, for an open/high resistance. If the circuits/connections test normal, test or replace the appropriate fuel injector(s).
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