Hey guys & gals, having a problem with a 04 Neon SXT! It keeps sending a P0204 trouble code ( which is the #4 injector circuit). Wire to PCM is good, all other injectors have 1V when running, #4 has 14V. Checked the + wire for V unplugged from PCM, 0V, Ohm all injectors, 13 Ohms. The injector is staying open and flooding to the exhaust. Car was running fine, changed the R motor mount and both torque struts and fired it back up and this problem started! So the questions are does anyone have a wiring diagram for the ECU to PCM to injectors? Has anybody had this problem before and had success fixing it? Thanks in advance, you may save the last three hairs on my head!!!

 

Thanks darthroush for the great post on FREE service manuals & wiring diagrams!!!

 

You're welcome!

 

Have you figured it out yet?

 

No Moparkyle, I think it might be in the PCM. Haven't found any wires melted together or any thing that might cause the 14V on the #4 injector circuit. Any ideal on what might be wrong? Have a PCM coming on Monday so I hope that is the problem!!!

 

You have 14V on the LB/BR wire?

 

Yes, 1V on the other 3!!! Also pulled the C2 loom and did a continuity test with ohm meter on all the pins, nothing! Any ideals???

 

Well 14V present after the injector can indicate a few things..

A shorted injector, which you have all ready dis proven by ohming it out.
A short to power which you could disprove by measuring for voltage on the ground side with the injector disconnected with everything on.
A bad ground. Could be in the pcm or otherwise.

I might be missing a few things. Does that manual in Darth's link have pinpoint tests in if for DTCs? Because those are usually very thorough in helping you chase problems.

 

I believe there are pinpoint tests. It's been some time since I've gone through the DTC diagnostics though...

 

Thanks Moparkyle, I hadn't downloaded the service manual with the DTC's in it at the time of my last posting but now I have! The K14 circuit, which is the #4 injector + circuit and the A142 is the grounding circuit. Everthing checks out to be bad PCM, the PCM was suppose to be here yesterday. I will post if that is the problem or ask for more HELP if not!!! Thanks again for the DTC's advice!!!