Hey all. New guy here. Thank you all in advance for the infinite amount of knowledge shared here. What a great resource!

OK 2004 with 115K. Never had any problems until a few months ago and now just cant find the fix!

I took a bad load of fuel on and ended up stalled out on the side of the road. Bled the water separator and made it home. Bled it out again, added some 911 additive and changed the fuel filters...... 3 times before I got it squared away. Ended up with a skip and bad injector.

Took it to the dealer and they changed the injector. Had problems within 10 miles on my way home. They then changed the EGR, Next trip changed the mass airflow sensor. At this point the truck was shutting off for a split second and dropping in RPMs slightly then running fine... just these infrequent hiccups. Now the dealer says its a bad harness 850 prepaid and 1K to install it. They say I can keep running it and come back whenever fits my schedule. Well it stopped happening so I never went back.

A month or so later it gets real cold out and the truck is struggling to start in the morning so I look and realize the glow plug light is only on for a second or two. I replace the glow plug control module and no change.

One day the truck just wont start. Cranks fine but no start. Fuel filters are new and I can hear the pump working when the key is cycled. Check the filter on top and can see fuel flowing in good too.

I pick up the harnesses I had paid for and install them myself (2 days in the garage for me). No luck.

I pull the FICM and take everything apart, looks OK so I put it back together and the truck starts. Great! Next day no start. I keep it in the garage and run the block heater. Now it starts some days and not others. When it does run it usualy skips a bit until I run it for 10-15 miniutes and then runs great.

I got a cam sensor with the harnesses so I put that in too. Still no start.

OK thats the story. If anyone has input Im all ears. The one thing I noticed is that when the truck is warm (from being inside & block heater running) I hear the usual clicking noises (I think they may be related to the injector pump?) the whir of the fuel pump and an air relief type noise coming from the turbo? If I get all three of these noises it is more likely to start but not always. If I don't hear the clicking it doesnt start.

What is the electronic clicking noise and why would it only be heard when the engine compartment is warm?

I hate to change the FICM without knowing it is the problem. I'm planning to check it for voltage according to the post I found here but if anyone has insight as to where else I should be looking Im all ears. Also I still cant get the glow plug light to stay on. Is there something else that would help with that? Im 4K into my truck that is only worth 9K and hate to spend too much more.

Sorry for the book.

 

It sure sounds like a FICM issue (or an electrical issue of some sort). Test the voltage (KOEO, cranking, and at 2000 rpms if possible). Let is know what you find. Just be aware that even if the voltages are good, sometimes the FICM is still bad. Do you know somone w/ a good FICM that could help you w/ a temporary loan?

Are you sure all your electrical connections are good? Grounds, harnesses and wire bundles, etc? Also, make sure your batteries are good (individally load test).

If you can't get it to start, try it w/ the EGR valve unplugged, the ICP sensor unlugged, and the EBP sensor unplugged.

 

I don't have access to a temp FICM. Connections all seem good. I just went through them all again today best I could without actually re-doing the entire harness. I will test the batteries they are original so they may be weak even though it sounds like it is turning over strong.

Im not sure where the EGR valve is? I dont know what an ICP is or where it might be and same on the EBP. Im sorry to be dumb but geratful for your help.

Do you have any insight on the electrical clicking noise when the key is turned on?

 

By myself so I put tested the batteries cold and they both read around 12.8v, I put the battery charger on one at a 250 and turned the key. The "electrical clicking noise" I described is back. That is a familiar and positive sign. It did not start though.

I'm going to leave it on the charger for a few hours. If I charge them up and it fires I'll be happy as a clam to just buy a couple batteries. I think I read another thread of yours though that indicated low batery tourture can result in damage to the FICM and maybe injectors?

Thank you for your help and patience.

 

Look over the info in the link below and it should answer a few of your questions:

6.0L Bible Table of Contents

 

After a couple hours on the battery charger, the noises all seemed right, quicker, louder and higher pitch whir for the fuel pump. Fired up but it was skipping on at least 2. After running 10-15 minutes it ran fine.

New batteries today for sure. Any thoughts on the glow plug light not staying on?

 

By the way. I can't really express how grateful I am for the help and in trying to do my part I am reading through the unbelievable bible post. I am so impressed with the wealth of info there. I don't have a ton of technical experience but this resource is just amazing. Thanks to all who have taken the time to enlighten others!

 

OK new batteries are in but no "buzz" noise from the high pressure injector side. I previously described this as an "electrical clicking" noise. I tried testing the FICM but did not get any where near the voltage I thought I was looking for 48V and got 15V and 17V on just 2 of the seven pins (on the right 4 pin side). In the FICM diagnostic post it describes testing the left pin? not sure on which one it means but of the three pins on the left none read much over 2V.

I think this is definately an electronic issue but I'm not sure it it actually is the FICM or if I am having a failure at the PCM. Seems strange that last night with a boost charge on my weak batteries it all came together but today with new batteries I get nothing. I did not have the block heater plugged in for todays failure. It is plugged in now and I will try it in a few hours. I cant seem to figure a relationship between the buzz of the injectors and the block heater.

I will try and read up on testing the PCM. Still not very long cycle for the glow plugs. I read in the bible that the glow plugs will not turn on if the oil temp is in excess of 138. Im not sure but when the block heater is on for several hours inside my heated shop it seems like the engine temp could be in that range.

Any thoughts??

 

check fues and powers / grounds at the ficm relay. pcm's are not knowen to fail often.

 

I think all connections are good. Ground at the ficm relay I will have to look up, find and check. I have a theory....

The buzz noise of the injectors is critical to start up. If I don't hear it, she don't start. I thought lack of buzz was caused by weak batteries but after battery swap Im not hearing it at all. Block heater was not on.

Im realizing that only when the block heater has been on for an extended time will it even think about starting. The buzz noise returns (with a good set of batteries or a booster charger on the old ones). And she will fire.

Could it be a combo.. if the FICM is not doing its high voltage job including preheating the spindle of the injectors maybe stiction is causing the injectors to seize up until the block heater has the engine temp up high enough to loosen up the oil or goo in there. BTW I am amazed at how hot the block heater gets the engine compartment, it is well over 100 degrees in there.

As indicated the FICM doesnt even seem close on voltage test so I am definately looking at it but it also occured to me that the ICP was a total biatch to get to in the rear under the turbo when I swapped out the harness. It had a bunch of oil on it and the new harness had a different connector than the original. I had to splice in the old connector (after a wipedown)on my new 850 dollar harness but did it with solder & shrink tube so Im feeling good about it.... mostly.... the little yellow ring that holds it firm and keeps junk out somehow didn't make it back in. I found it on the floor after I had the truck fired and out of the garage. Havent had the spirit to go back in for that rascal yet.

To make things worse I have a banks six gun in there. I realized today it is throwing an ICP code. Im planning on pulling the six gun if I can go back to factory settings but have to verify that I dont have to put a new chip in or some other software before I move forward. According to the banks manual so far it seems the answer is no.

Now I don't know if the ICP will cause low voltage at the FICM or if the low voltage at FICM is causing the error code on the ICP.

God help us all.

 

Update for anyone who is still interested.

I checked the voltage at the FICM again after reading the test proceedures a few more times & I have the spec 48V on the top lug. I read somewhere if I disconnect the ICP I might get it to fire by tricking the FICM into a default setting. Looks like I'm going in after that rascal after all.

If that doesnt work I guess I'll try to remove the banks equipment. I'm worried about the MAP sensor. It says in the banks removal instructions to disconnect the banks lead and replace the factory lead.... No clue what the installer did with that, I had hoped it would be dangling around somewhere! I guess that might be for another post.

 

OK well ICP trick did not work. I did get the yellow grommet on the connecter though. The connection had oil on it. Not sure if that means the ICP sensor is bad but I cleaned it up and put it all back together. Good positive snaps on all connectors. I'll check the voltage again on the FICM while I have such good access.

Im back to square one. No "buzz" on the injectors when the key goes to the on position. Anyone have any clues as to what else would cause that? I had this puppy running like a charm last night???? Seems like heat in the block from the heater and a booster charge from the charger gets it to buzz.

 

someone can correct me if i'm wrong, but i believe i have read in other posts that if the icp had oil on it. the icp was bad. hope this helps.

 

Okay, after reading through all the posts in this thread, I can't help thinking why in the world you wouldn't have just replaced the ICP sensor outright, if you spent the huge money on an engine harness and replaced it. This is especially given even the fact that you already mentioned that there is oil residue present, just waiting to destroy your new harness not to mention that failures of this sensor are extremely common for these 2003 engines. I hope you didn't leave the heat shield out when re-installing everything. The "buzzing" that you hear is your injector(s) precycling when you hit the RUN position with the key. I would say your best bet, is to run an injector buzz test with a scan tool that is capable, when the truck doesn't start, to determine which (if any) injector(s) are faulty.

 

Thank you for your insights. I was not aware that if the ICP has oil on it, it is bad.

What I find troubling is that if the ICP was the cause I should have been able to by-pass it by disconnecting it and tricking the FICM into a default setting. That did not happen. I wasn't sure that the ICP will cause no start condition (not cold, my garage is around 65) followed by an occasional misfire or skip period of about 5-10 minutes then run perfectly. Most of what I have read indicates that it will run rough or skip throughout the engine on cycle as a typical symptom and sometimes no start.

I did not replace it because I didn't know for sure it is the root cause. I will now replace it if oil means its bad. I don't see the relationship to the block heater being on for long period of time and the ICP working vs no block heater no ICP. However if this is the device that tells the ignition to "buzz" the injectors when the key is turned on.. it seems like a potential candidate.

This truck is worth around 9K running. I just put 4K into it at the dealer. They reccomended the harness, not my diagnosis. If I had them do it I would have spent another grand putting it in. It needs lots of stuff. I also noticed I have an oil leak somewhere in the turbo system and although no one has commented on the glow plugs, I definately think they are part of the problem as the light only stays on for a second or two before shutting off.

My point is that I don't have the option of just replacing stuff anymore. I can't afford to and it is really not worth it. The dealer will give me 3K for it not running. However, I can't afford a new truck right now and I need to get to work reliably when there is work. I am greatful for the help and will continue to try and diagnose the problem.

I'm trying to just get her running for a month or two until things get better for me and I can make a reasoned decision on what to do, instead of making a desperate decision in the middle of winter because I need a truck immediately.

Im heading down to the garage now, won't surprise me at all if she starts or doesn't! I'll keep you posted and get that ICP in today.