Sierra 2500 Denali 2WD V8-6.0L (2011)
‹› If the difference is more than 3 ohms, add all of the fuel injector resistance values to obtain a total resistance value. Divide the total resistance
value by the number of fuel injectors to obtain an average resistance value. Subtract the lowest individual fuel injector resistance value from
the average resistance value. Compute the difference between the highest individual fuel injector resistance value and the average resistance
value. Replace the fuel injector that displays the greatest difference above or below the average.
Important:
*
DO NOT perform this test if the engine coolant temperature (ECT) is above 94°C (201°F). Irregular fuel pressure readings may result
due to hot soak fuel boiling.
*
Verify that adequate fuel is in the fuel tank before proceeding with this diagnostic.
AFIT Test Procedure
1. Turn OFF all accessories.
2. Turn OFF the ignition.
3. Install the AFIT. Refer to the AFIT User Guide.
4. Turn ON the AFIT and select the vehicle.
5. Turn ON the ignition and perform the Injector Test.
‹› If the AFIT aborts testing due to fuel pressure or fuel leak down, refer to Fuel System Diagnosis (Without FPCM) (See: Fuel Pump/Testing
and Inspection)Fuel System Diagnosis (FPCM) (See: Computers and Control Systems/Testing and Inspection/Component Tests and General
Diagnostics).
6. View the test results.
‹› If any injector exceeds the recommended tolerance, replace the injector(s), E-85 only. All other engine, refer to Fuel Injector Cleaning (See:
Service and Repair/Procedures).
Repair Instructions
Perform the Diagnostic Repair Verification (See: Computers and Control Systems/Testing and Inspection/Diagnostic Trouble Code Tests and
Associated Procedures/Verification Tests and Procedures) after completing the diagnostic procedure.
Fuel Injector Replacement (See: Service and Repair/Removal and Replacement)
