Diagnostic Aids
WARNING: This page is about a different car, the 2019 GMC Savana 3500, 2019 GMC Savana 2500, 2019 Chevrolet Express 3500, and 2019 Chevrolet Express 2500. However, it is still accessible from the selected car via links, so may be relevant.
- Downloading the AFIT test results to the shop TIS terminal will clearly show which injector is at fault by the bar graph turning red.
- On some vehicles cleaning the injectors may be performed if the graph shows erratic or values close to the specified values.
- A second test can be performed to verify repair. Compare the first balance test to the second.
- Monitoring the misfire current counters, or misfire graph, may help to isolate the fuel injector that is causing the condition.
- Operating the vehicle over a wide temperature range may help isolate the fuel injector that is causing the condition.
- Perform the fuel injector coil test within the conditions of the customer's concern. A fuel injector condition may only be apparent at a certain temperature, or under certain conditions.