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Home >> Chevrolet >> 2002 >> Blazer 4D Utility, 4WD, Part Time >> Repair and Diagnosis >> External Pages >> Different car >> Section 87 (Engine Controls - Self-Diagnostics - 6.6L Diesel) >> Diagnostic Tests >> DTC P0201-P0208: Fuel Injector Control Circuits >> Test Description

Test Description

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The numbers below refer to the step numbers in the diagnostic procedures.

  1. 2

    This step verifies that the condition is not intermittent.

  2. 4

    This step determines which set of fuel injectors the circuit condition is affecting. If DTC P1261 is set, then a condition exists on cylinders 1, 4, 6, or 7. If DTC P1262 is set, then a condition exists on cylinders 2, 3, 5, or 8.

  3. 5

    This step tests if a ground is constantly being applied to the fuel injectors.

  4. 6

    This step isolates which circuit is causing the condition. If the test lamp turns OFF when a multi-way connector is disconnected, test the affected circuits for a short to ground.

  5. 7

    This step tests for an open circuit. If the Digital Multimeter (DMM) displays OL on all of the fuel injector circuits, the ignition voltage circuit is open.

  6. 8

    This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open.

  7. 9

    This step tests for excessive resistance in a fuel injector circuit.

  8. 10

    This step is testing for a short between the ignition feed circuit, and the fuel injector command circuit. If the resistance of the circuits is less than 0.3 ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms.

  9. 11

    This step tests for a short to voltage on a fuel injector circuit. If the test lamp illuminates, a short to voltage is the cause of the condition.

  10. 12

    This step isolates which circuit is causing the condition. If the test lamp turns OFF when a multi-way connector is disconnected, test the affected circuits for a short to voltage.

  11. 13

    This step tests if a ground is constantly being applied to the fuel injectors.

  12. 14

    This step isolates which circuit is causing the condition. If the test lamp turns OFF when a multi-way connector is disconnected, test the affected circuits for a short to ground.

  13. 15

    This step tests for an open circuit. If the DMM displays OL on all of the fuel injector circuits, the ignition voltage circuit is open.

  14. 16

    This step tests for an open circuit. If the DMM displays OL on one of the fuel injector circuits, the fuel injector command circuit is open.

  15. 17

    This step tests for excessive resistance in a fuel injector circuit.

  16. 18

    This step is testing for a short between the ignition feed circuit, and the fuel injector command circuit. If the resistance of the circuits is less than 0.3ohms, test for a short between the circuits. If a short cannot be found, the fuel injector may be the cause of the condition. The normal fuel injector resistance is between 0.3-0.4 ohms.

  17. 19

    This step tests for a short to voltage on a fuel injector circuit. If the test lamp illuminates, a short to voltage is the cause of the condition.

  18. 20

    This step isolates which circuit is causing the condition. If the test lamp turns OFF when a multi-way connector is disconnected, test the affected circuits for a short to voltage.

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