2002 Grand Caravan P0204 OBD2 Code: Injector Circuit Fault Diagnosis

My 2002 Grand Caravan is showing a P0204 diagnostic trouble code, indicating a circuit issue with the #4 injector. I've checked the wiring harness and confirmed that all connections are secure and in good condition. However, the injector still isn't activating. The fault persists despite these checks. Any advice on how to troubleshoot or resolve this specific P0204 issue for a 2002 Grand Caravan would be greatly appreciated.