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Discussion Starter #1
January 30th drove three miles out and three miles back. CEL came on a few days before but I didn't read it. January 31 engine started, went to limp then died. Two more times it started clean, drove 100 yards, limped then died between the posts of my gate. Fortunately neighbor was nice enough to push then tow me back to the shade tree, really (no garage).

It's a ten year old truck with 337,+++ miles. The original harness repair was done by a diesel shop 6 years ago. I didn't know about the Duramax habit of losing #2 and/or #7 or the chafing points back then. I got it towed in and whatever the diesel shop did worked and worked well for six years.

Back to the present...the DTC's I pulled the day it happened were P0202, P0203, p0205, P0208 and P2149. I have spent hours reading this sight and it's many posts on this issue. I started at the alternator bracket but it was wrapped with heater hose. Ice picked 2 and 8 just for the heck of it though I'm now pretty sure the shop had replaced several of the injector connectors because wire color does not mesh with the FICM wiring diagrams.

I've gone over wires as closely as I could from the FICM to the main wiring harness connectors and out to connectors. Out of frustration I have replaced ALL 8 of the injector connectors, soldering and shrink-tubing each connection. At some point of removing old, crumbling protective tubing I nicked a wire that resulted in additional codes now encompassing all 8 cylinders and both banks. Eventually found that nick; I cut, butt connected with solder and wrapped. Back to the original 4 (2, 3, 5 & 8).

With all that, now the question part. After over a month of wire tracing and multiple inspections, I keep coming back to the Bank Two FICM Wiring connector. The insulation of several of the wires coming out of the connector are darkened and the wire feels stiffer than the same wire 4-5 inches from the connector. I found the wiring diagram here on DP and the part number as well (1928403462) but haven't been able to find the part anywhere.

Has anyone ever heard of or experienced something similar? I've tried to find this part so I could replace the first foot or so of wire just to rule this piece out.

The other screw up I made was on a yellow wire w/ green tracer. I found what I thought was a burn mark on the wire insulation. I decided to cut out the darkened piece and replace it. I cut it and found that it had FOUR smaller wires inside as well as a metallic shielding around all, like coax. I soldered in four new pieces of wire to replace the dark section but wasn't able to configure something to mimic the shielding.

Yes, there is a good diesel shop in town, but the last time it went in cost me almost $3,000. I have a daughter getting married in two weeks and then April 15th right after. There just isn't dollars available to take it in. The truck is my work vehicle. I've been able to get by by driving my wife to work in the morning and picking her up at 5. Amazing how much stuff a minivan can hold, but it gets looks at construction sites.

I'm looking for the magic words that somebody out there has; words other than check for chafes and replace/ice pick #2 and #7. I do have to say that this site is a terrific resource. Once I figured out I needed JAVA, it is really easy to search and contains loads of valuable information. My thanks to all the 'replyers' attempting to help us 'questioners'!
 

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Welcome here. So after all your repairs, is the truck running? Have you cleared all the codes and start the truck to see which ones come back? Sorry if I'm not reading your post correctly.
 

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I just cleaned up the harness and found the yellow wire a few weeks ago I didn't cut it( I'm glad now) I wrapped it up and covered with new wiring protector cured my issues, also I ice picked all connectors and put dialectic grease everywhere
 

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Discussion Starter #4
THanks Dieseldad97 and hihosilver.

I have cranked the motor each time I've done something, like greasing a connector and plugging back in. I clear codes after each attempt. Starts are always straight into limp mode. Run time is usually 3-5 seconds before it dies. A couple of times it has run in limp for up to 15-20 seconds, never longer than that and always in limp mode.

I have not done the ice pick trick on the new connectors as all are new.

I'm in the midst of putting dielectric grease on bank two connectors - I've done 2, 3 and 5. Today I'll remove the fuel filter bracket and grease #8. I have greased both 1 and 2 banks of the FICM connector and both connectors on the main harness.

I have a pile of post it notes with codes from back in February. I'm on page three of a note pad now. I'm keeping records of codes after each start attempt, looking for any patterns.

I'm wondering about going to a continuity tester; pulling one injector connector at a time, inserting a U shaped copper wire into the two slots of the connector, then testing continuity at the FICM connector. Has anybody tried this? Any thoughts about whether this would help?

After six weeks, I'm really getting creative in my search for the problem(s). Additional ideas will be greatly appreciated.
 

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Any chance this is a fuel problem? How old is the fuel filter? Have you pushed the plunger to see if it gets hard? Any wetness by the air screw? Just thinking out loud.
 

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Discussion Starter #6
Thanks Dieseldad97. THat's what I'm looking for is thinking out loud. I have disconnected the fuel lines twice in getting to wiring to check and insulate. After each a did an air purge on the filter housing and pumped up pressure. Fuel filter is a few months old but given the codes I'm still looking at electrical.

After I posted my last bright idea I Googled and found there are things called NOID lights that check injector harness continuity, but they send a Duramax into limp mode if used. It's been raining but the sun appears to me coming out. I think I'm headed out to my tree and seeing if my multimeter test works or tells me anything.

Keep the ideas coming, PLEASE!
 

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Something I read on another forum:

The P0208 is an Injector Drive 8 Fault.
The P2149 is an Injector Positive Voltage Relay Control Circuit Group 2.

DTC 2149 Circuit Description:
"The FICM supplies high voltage to each fuel injector on the ignition voltage circuits. THe FICM energizes each fuel injector by grounding the command circuit between the FICM and the fuel injector. The FICM monitors the status of the ignition voltage circuits and fuel injector command circuits. When a fuel injector circuit condition is detected by the FICM, all of the fuel injectors on the affected ignition voltage circuit will be disabled. If a circuit condition is detected on a fuel injector circuit for cylinders 1,4,6, or 7 DTC's of P0201, P0204, P0206, P0207 {respectively] will be set, along with DTC P2146. If the circuit condition is detected on a fuel injector for cylinders 2, 3, 5, or 8, DTC's P0202, 0203, 0205, 0208 [respectively] will be set along with P2149."
 

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Discussion Starter #8
Thank you again. I came across this information as well but not nearly as well explained. I'm pretty much ignoring the 2149/2146 codes and focusing on the 01-08 codes. I have the FICM banks labeled on each respective FI Connector to help keep me straight.

I ran a continuity test on the odd numbered (passenger side) connectors. I put the positive probe on the FICM pin and grounded directly to the battery negative side. I don't know what I'm doing but I'm throwing shtuff at the wall and trying to see if anything sticks. With the continuity test, I"m looking for an anomaly but didn't see one on the four I checked before rain set in.
 

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Discussion Starter #9
Howdy again,

Is this in any way significant?

I had disconnected both fuel lines in order to get to the wires running across the top of the block. After reconnecting I purged the system at the filter housing but I guess not enough. The engine cranked but didn't fire. For the heck of it I checked codes and got P0202, P0203, P0205, P0208, P2146, all relating to the second(?) FICM bank. I cleared everything then repeated without additional priming to see if it would repeat and it did, exactly.

Does this indicate anything? Point to something I can chase?

I don't know that it not catching makes any difference in how these fuel injector codes are set.

Still working under the tree between rain storms.
 

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make sure your fuel system is tight ( no air) and primed and everything plugged in if no fire at all then you might have ecm issues
 
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Have you checked your ground points?
The motor-to-frame-to-battery-to-motor grounding points circle of hair pulling yet?
Sounds like you are headed there next, if you haven't yet, judging by all the posts...
Search for 'Clean grounds' or 'harness grounds'
There is only a few that could make those symptoms.. I think...
 

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Discussion Starter #12
I havent checked grounds. it never occurred to me to look with the codes im getting.

I am starting a process of clipping each wire, from the main harness, that travels from harness (drivers side) under a metal coolant pipe toward the passenger side. After clipping i'm really looking and feeling for any defect, replacing a section of wire if needed. Otherwise reconnecting with a butt connector, soldering and shrink wrapping.

The reason i'm working where i am is that the factory flex pipe was in horrible condition, chunks gone, the rest cracked and brittle. If this exercise doesn't fix it I'm going to do the same to all wires connected to the second bank connector of the FICM.

At the FICM, there are a couple of wires that just 'feel' wrong, like the wire inside the insulation has gotten less flexible, and almost feels like it has swollen in these areas (gotta be a hallucination but none the less, that's what it feels like to me).

I'm getting really good at soldering connections under the hood and only rarely scorch my arm or knuckle hair anymore.

This has been one heck of an exercise. I'm past frustration, past anger, past giving up. It's just become part of the daily grind. At least I'll have an extra hour of sun light tomorrow. The rain has passed but the mosquitos have gotten so thick at dusk that I have to give up - don't want to get that zeeca thing, right?
 

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Well I figured since you are dissecting the harness, checking/cleaning grounds would be a bad idea. IMHO, I tend to NOT, connect, disconnect, connect, disconnect.. etc the big computer connectors(like the ficm) mainly because it increase's the chance of damage/contamination. BUT, have you looked into the harness and computer sides of the connection? IE with a magnifier? and an 'ice' pick, prod on the pins, looking for a broken/cracked one? I could've sworn I had read about someone getting the 2149 code caused by a Ground being loose.. I haven't found it yet..
 

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Discussion Starter #14
Two specific questions -

From the FICM there are command/control wires that go to the injectors and there are sensor wires. Given the codes I"m consistently getting (P0202, P0203, P0205, P0208, P2149) does the short have to be in one of the 12-14 gauge command/control wires or could it be in one or more of the smaller, 18-20 gauge, sensor wires as well?

Can an injector problem cause a bank failure code or are there other codes specific to a bad/failed injector? With all the wire checking I"ve done, could the problem actually be a bad injector all along?

Thanks-
 

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Since each injector only has two wires running to it I'm not sure where the sensor wire falls into things. It seems to me that the only way an injector can short is in the command/control wire.

Have you messed with your FICM and verified that it's not doing all of this, I've got my own gremlin that appeared and left but I scared when it will come back, one of the things that SoCal Diesel brought up was the FICM. They claim that while they don't go bad that often they do sell more LLY FICM's than ones for the LB7 trucks.

Also as I understand it the FICM simply amplifies the injector signal that it gets from the ECM. If the Injector signal is off it could be a product of the ECM too?
 

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My 2005 died on the road and wouldn't restart at 70k miles. The FICM was replaced under warranty. Problem solved.

The new FICM had a warning label about power engine washing. I think mine might have failed due to water intrusion. A prior dealer had washed the engine a couple of times.
 

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I am having trouble with mine too. I have been getting P0202, P0203, P0205, P0208, and P2149. I replaced some connectors and ice picked them all. Checked my FICM harness and someone has gone through to fix them in the past. I removed all the pieces plastic and inspect the wires shaking while the vehicle was running and I couldn't duplicate the error. Any help would be great!

@CHEVYJEFF, I read your thread and I am going to look into my harness this weekend. One weird thing my truck does is that it throws up P0202/P2149 and sometimes when I clear it, the truck runs fine for a few minutes then jumps to P0208. Sometimes it runs to P0203/P0205/P02149. It is rare for it to throw the code for all 4 injectors at the same time. Did anybody else experience this?
 

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Discussion Starter #19 (Edited)
I"m back - continued problem. I've had to lay off of the truck for a few weeks but got back on it seriously last week. I had a hard time finding a wiring harness but finally ran across the new part number and tracked down an OEM new harness.

I took my time, pulling wires one at a time and plugging in the new ones.

It didn't change a thing. Still getting (0201, 02, 03, 04, 05, 06, 07, 08, 2146, 2149) then just the (2-3-5-8, 2149) circuit then it will run for a while before going into limp, then it will run for 10-15 minutes so I turn it off, restart and get immediate limp (or not...). It's random as to codes except that the (0202, 0203, 0205, 0208) side comes up more often.

I now have all new wire from the main harness connectors, through the FICM and to injectors and sensors.

QUESTIONS:
1) Given the codes I'm getting, does the problem HAVE to be between the FICM and an/the injector(s)?

2)IS IT POSSIBLE the problem is between the FUSE panel and the harness connector(s)?

The FICM has not been tested. Everything I've read says this is rarely a problem so I've haven't looked there. Is there a way for me to test the FICM at home? or do you have to plug it in to a computer of some sort?

Can an inector itself cause this type of problem?

Today I'm going to go back through each injector connector, pull, add dielectric grease and plug back in.

The only time I can really do testing is when my wife gets home. She does the cranking, code reading and clearing while I'm up pulling sections of wire taught then manipulating wires when it does start. Last night we did this through twenty-two starts.

Again and always, thanks in advance for any replies and information.
 

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My truck is on it's 3rd FICM now, including the original. Last one went in at about 540k miles. As detailed in another thread the engine was stumbling and cutting out last summer on 100* plus days running on freeway. Never set a code except during no start cranking once. Took 6 months of fooling around before I replaced FICM with a new part from dealer. No more issue. Not saying that's your problem Ghillie62 but maybe worth installing a known good FICM for a test. No way of testing an FICM that I'm aware of. At some point you have make that educated guess.You can split it apart and see one side of the PC board. The board is bonded into the case so you can't see the solder on the bottom without cutting it apart. When I hit the old FICM with a screwdriver handle by the side of the road one hot day and it started right up, I decided maybe I was on to something..
 
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