Component Testing
WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.
Fuel Injector Coil Test
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
- Ignition ON, verify the scan tool hood position parameter displays Open.
- If the hood position does not display Open, refer to Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
- Verify the resistance of each fuel injector with one of the following methods:
- If the engine coolant temperature (ECT) sensor is between 10-32°C (50-90°F), the resistance of each fuel injector should be 11-14 ohms.
- If the injectors measure OK, perform the Active Fuel Injector Tester (AFIT) Test Procedure.
- If not within the specified range, replace the fuel injector.
- If the ECT sensor is not between 10-32°C (50-90°F), measure and record the resistance of each fuel injector with a DMM. Subtract the lowest resistance value from the highest resistance value. The difference between the lowest value and the highest value should be equal to or less than 3 ohms.
- If the difference is equal to or less than 3 ohms, refer to AFIT Test Procedure below.
- 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.
- If the engine coolant temperature (ECT) sensor is between 10-32°C (50-90°F), the resistance of each fuel injector should be 11-14 ohms.
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
- Ignition OFF, open the hood to disable the Auto-Stop function. Refer to Hybrid Modes of Operation Description .
- Ignition ON, verify the scan tool hood position parameter displays OPEN
- If the hood position does not display OPEN, refer to Diagnostic Trouble Code (DTC) List - Vehicle for DTC P254F.
- Turn OFF all accessories.
- Turn OFF the ignition.
- Install the AFIT. Refer to the AFIT User Guide.
- Turn ON the AFIT and select the vehicle.
- 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 Injector Diagnosis (CH 47976) , Fuel Injector Diagnosis (J 39021 or Tech 2) .
- 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 .