Check Engine Light On, DTCs P0171, P0300, P1174 Set (Perform Injector Test/Replace Injectors and Reprogram ECM, if Necessary)

Some customers may comment on the check engine light being illuminated.

A scan tool may reveal DTC P0171, P0300 or P1174 set as current or in history.

This condition may be caused by the plugging of one or more of the injector director plate orifices which results in a lean condition.

Important: This condition cannot be corrected by cleaning the injector(s).

Perform an injector balance test using the Active Fuel Injector Tester (AFIT), CH-47976. Refer to the Fuel Injector Diagnosis (w/CH47976) procedure in SI. If any injector is identified as having a lean condition, replace all four injectors with the revised injectors. After installing the new injectors, reprogram the ECM with updated calibration files using the TIS2WEB Service Programming System (SPS) application. There are two calibration part numbers that are valid for "Engine Operation". Select the part number with the description that reads for vehicles with second design injector. The injector has a dark blue overmold color for this repair.

Important: The fuel injectors must be replaced and the new calibration files must be installed to ensure a complete repair. Failure to perform both repairs will result in the customer returning with the same condition.

If a vehicle returns with the same condition after having this repair performed, the technician should first verify that the complete repair was performed before continuing with SI diagnostics.

Important: For claims to be paid, injector balance test results must be recorded on the repair order.

For vehicles repaired under warranty, use: