Conditions for Setting the DTC
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.
DTC P1248
The ECM detects the injector 1 high voltage supply circuit is shorted to the injector 1 high voltage control circuit for greater than 500 ms.
DTC P1249
The ECM detects the injector 2 high voltage supply circuit is shorted to the injector 2 high voltage control circuit for greater than 500 ms.
DTC P124A
The ECM detects the injector 3 high voltage supply circuit is shorted to the injector 3 high voltage control circuit for greater than 500 ms.
DTC P124B
The ECM detects the injector 4 high voltage supply circuit is shorted to the injector 4 high voltage control circuit for greater than 500 ms.