2006 Dodge Ram Hemi V8 Fault Codes P0202, P0204, P0304 - Injector Signal Issues
I need to open the wiring harness to inspect the injector wires as they are protected by a cover, making it difficult to trace. During testing with the ignition on (but engine off), the test light remained lit for both cylinder #2 and cylinder #4. However, when the engine is running, only cylinder #2 shows a blinking signal, while cylinder #4 shows no light at all. This behavior suggests an issue with the injector signal or ground circuit for cylinder #4. The fault codes P0202 (Injector 2 Circuit Malfunction), P0204 (Injector 4 Circuit Malfunction), and P0304 (Cylinder 4 Misfire) point to a possible wiring or electrical connection problem in the fuel injection system.
If the test light stays on without blinking when the engine is off, it indicates a broken signal or ground wire. Refer to your repair manual for the wiring diagram of the 2006 Dodge Ram Hemi V8, specifically locate the injector #4 signal and ground wires within the connector pins connected to the ECM. You can safely disconnect and replace just that wire to resolve the issue. If you're not confident in performing this repair, do not attempt it yourself—consult a qualified mechanic. This solution is based on known electrical patterns for these fault codes and should help diagnose and fix the problem.