Diesel Place banner

P0380 and pegged oil pressure after replacing Injectors

Question: 
2K views 8 replies 2 participants last post by  Wetdirt01 
#1 ·
I have a puzzle that I can't solve. stock '02 6.6 duramax (california emissions) 170k miles

I needed to replace my injectors and have the time and tools to do so, but am a bit of a hack. I watched all the videos and read all the posts about doing the change. Everything seemed to go well. I primed the fuel lines and it fired up and runs great.
HOWEVER, there is now a glowplug code (P0380A). I previously replaced all the glow plugs but thought one might have coincidently gone bad. I ohm'ed them all and they seem to be in tolerance. On top of the code, the oil pressure gauge is pegged. It has never been a problem before.

I suspect I have forgotten a plug, cut a wire, or damaged some connection. I have looked over what I can, but can anyone give me some direction where those two issues might be connected? Would the 175A fuse be blown and affect both items? The glow plugs worked great before the injector swap so I hesitate to think it is the relay, but....
 
#2 ·
Hello Almond Farmer,
Interestingly enough I just did a Head gasket job on my truck. After completing the reassembly all went well. When I started the truck I now have P0380 glowplug error code, low Oil level light (DIC) & oil pressure gauge is pegged. My truck is an 01.
What I have been able to trace down is on the 01 & I believe 02, there is a 3 wire connector just behind the Main engine bayonet connector. I have lost or misplaced what ever plugs into this connector.
The wires are Brown, Brn/white Pink/yllw.
Pink and yellow go to the grounded side of the Glow plug controller relay.
Brn/wht is the oil pressure gauge
Pink&yellow is Low oil level.

The first wire in this connector when I ground it turns off my low oil level in the DIC, the middle wire when I ground it takes my oil pressure gauge to "0". The third wire when I ground it will allow me to clear the P038 glow plug code.

I hope this helps you.
So that now brings me to my question; since grounding the middle wire takes my oil pressure gauge to 0 I don't think it is just a grounded plug.

I now have a favor to ask. When I disassembled the truck I vaguely remember this connector but cannot remember what was connected to it. When you check this out could you please get a photo and let me know what you find connected to this connector.
It is difficult to find much information on this, I have spent a considerate amount of time searching.
P.S.
I believe 01~ 02 had this 3 wire connection then changed to a 6 wire in 03. The difference is that the 01/02 oil pressure gauge are just standard air core motors and did not operate through the ECM.


Good luck Gary
 
#3 ·
Hello Almond farmer,
I left out a small detail, the harness connection above I am talking about is a 3 prong male with a yellow center. there is also a 3 socket (Female) connector on the opposite side, that appears it would possibly connect to one another. However, they each only protrude from the harness by about 3 inches or so.
Gary
 
#4 ·
Hello Almond farmer,
I left out a small detail, the harness connection above I am talking about is a 3 prong male with a yellow center. there is also a 3 socket (Female) connector on the opposite side, that appears it would possibly connect to one another. However, they each only protrude from the harness by about 3 inches or so.
Gary
Thanks for the response. There seems to be some commonality between our two problems. I'll dig into mine this morning and take some pictures. For now, I will tell you, my truck is a California emmissions truck. That means (and you may already know) my glow plug controller has three connectors. Were you referring to those sockets and connectors?
Also, I believe your are correct when you say the '01 and '02's have a different oil sensor system. They should only have one wire that goes .... uhm, directly? to the dash. Apparently, not. I've been trying to trace the wire thinking it would lead me to my problem. It would make sense if it lead me to your problem and missing connector.
 
#5 ·
OK, I found one and, MAYBE, both problems and relationship.
I dug into the top wiring harness location (not into the harness itself) and found a connector disconnected. It wasn't one I had disconnected, but, due to messing with everything, it had come undone. I may have to replace the clip. It was the wire coming from the oil pressure sensor which fed up throught the front of the motor, under the A/C pump and up to the (????) power block in the middle of the top of the motor (the block that has the positive wire from the glow plug controller). I plugged it back in and the oil pressure gauge works fine. However, the Glow plug curcuit code was still on. It started a little tough, but that could have been due to slight air left in the fuel lines or something related to the recent injector replacement. I drove the truck a bit and it seems to run well with no leak (yet :) ). Therefore, I reset the ecm with my scan tool. That turned off the code, but I don't know if it will come on at next start. I'll have to drive it a bit to store enough data. I'm not sure.

Picture of where the clip is located (red arrow). It goes into the harness where the main wiring harnesses are clipped in just under and behind the foreward driverside injector clip is located.
634865
634866
 
#6 ·
Congratulations I really thought this would solve your problem as our problems were the same.
It seems this is the same connection I cannot locate. I have the small end that sticks out of the harness on top. what I am missing is the other side of the connection. I have no idea where the wire is routed or what it connects to. I know it is very difficult to see with everything in the way, but can you tell where the wire is going from the connection in the harness?
 
#9 ·
Good news, I started back tracing and checking wires. I looked again at the female connector on the passenger side & how it appeared to be the same ( matching) connector to the one on the drivers side. Boom, Ahh hha, the wire coming up from the pressure sending unit, I pulled across the engine & connected it to the manifold pressure sensor. I pulled all the a/c compressor Upper radiator pipe where I could get to the other connection unplugged the manifold pressure sensor and it plugged right into the "Extra" female connector on the passenger side, pulled the wire back out from across and sent it down the driver side wallah it plugs directly into the "Mystery" connector.

Checked the oip pressure gauge and it is correct.

Glad I could help you & thank you for your help.

Gary
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top