P0204 and P0304 Fault Diagnosis - 2002 Ram 1500 4.7L Engine Wiring Issue
I'm currently working on a 2002 Ram 1500 with a 4.7L V8 engine. During the repair, someone cut the wiring harness in the engine bay where it connects to the powertrain control module (PCM). I've successfully reconnected all wires and restored basic engine operation, but the number 4 fuel injector is not functioning properly. The vehicle now shows diagnostic trouble codes P0204 and P0304. I'm looking for a reliable wiring diagram with color codes specifically for the fuel injector circuit to the PCM, particularly for injector #4. If anyone has access to an official factory wiring diagram or a trusted online resource (such as a PDF or link), I would greatly appreciate it. Thank you in advance for your help.
If the only issue is P0204, focus on checking the wiring to fuel injector #4. At the injector, one wire provides 12V power and another connects directly to the PCM. The most likely fault is an open circuit in the signal wire from the injector to the PCM. The correct wire for injector #4 is typically labeled 'ltblu/brn' (light blue/black), which serves as the signal wire to the PCM—this corresponds to circuit K14 and cavity #16. To verify, use a noid light to test for proper signal from injector #4. Note: There is no official factory wiring diagram or PDF available in this forum that includes detailed color codes or circuit references for this specific component.