HHR L4-2.2L (2007)
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. 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).
Fuel Injector Coil Test (W/J39021 or W/Tech 2)
Fuel Injector Coil Test
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 Fuel Injector Balance Test-Fuel Pressure Test. See: Computers and Control Systems/Testing and
Inspection/Component Tests and General Diagnostics/Fuel Injector Balance Test-Fuel Pressure Test
‹› 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 the Fuel Injector Balance Test-Fuel Pressure Test for further diagnosis of the fuel
injectors. See: Computers and Control Systems/Testing and Inspection/Component Tests and General Diagnostics/Fuel Injector Balance
Test-Fuel Pressure Test
‹› 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.
* Before proceeding with this test review the User Manual CH 48027-5 for Safety Information and Instructions.
Fuel Injector Diagnosis (w/J 39021 or Tech 2)
Fuel Injector Diagnosis (w/J39021 or w/Tech 2)
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. See: Testing and Inspection/Initial Inspection and
Diagnostic Overview/Diagnostic System Check - Vehicle
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.
