Glowplug controller question

[houstonrealtor]

So while I am mechanically inclined, my 89' M998 is the first diesel and 24v system so I am a little unsure of what some of the components are. A few weeks back my "wait" light started to come on for just a second then go off but it still started fine. It did that a few times and then started working normal again and staying on 10-15 seconds. I drove it Saturday with no problem then when I went out to start it Sunday morning the gear selector was in "D" like someone was in there fooling around with it (I may have accidentally left it in gear but I am not sure). Well when I went to turn the ignition on the wait light never came on and the engine would not start. I tried a few times and it wouldn't start, finally by batteries fell to about 19v so I disconnected them and charged separately and tried again. The light wouldn't come on but I finally got it to start after turning over for about 20 seconds.

I checked for voltage at my rear left glow plug and had no voltage, I turned the ignition switch over and the amp gauge does not drop and I am now lost on what to do.

I have a SSI control box NSN: 6110-01-491-2152 Is there a way to test or repair this box? I'm not sure where to find the TSU or what it looks like but I found what I think is the TSU and got the number 19207-12338772 (very likeley could not be the TSU).

From what I read this particular control box does not use the TSU (which makes me wonder why I would have a TSU if it is not used) so I am figuring the only possibility is the control box being bad. What circuit does the neutral safety switch complete? Would it still turn over if the neutral safety switch was bad? Also I have read about a glow plug protector, what is that and could it be the culprit?

Thanks in advance and please excuse my lack of knowledge on this subject, I am trying to learn as much as possible so someday I may be able to contribute to this forum

 

[houstonrealtor]

Another off topic question but when I was digging around trying to find the problem I noticed that I have a 192c7-122589312 yellow sensor in the back center of the block and I looked up the p/n and it seems to be a tachometer sensor which I don't have a tach so why would I have a sensor???

 

[Lawdog734]

I had the same issue not terribly long ago - can I guess that you were getting light gray smoke out of the exhaust when you were cranking for 10-20 seconds? The light will flash for a moment and then you're cranking. Starting up after its been running doesn't seem to be an issue, but that initial start - especially when it's cold is a bear.

I ended up changing the control box - ya might as well change the glow plugs while you're at it and install a ground harness.

Retiredwarhorses, while sometimes seeming to lack a sense of humor (Relax ) did a good writeup regarding this issue in the checklist thread at the top of the forum. I've copied and pasted it below.

i see post after post after post with this same issue, you guys really need to look up in the archives past issues because this one comes up every month....now, this starting system is not difficult, but you MUST and I repeat MUST start with known good parts. I for one use the Kascar non-swell glow plugs, while they are expensive, I have never had an issue after numerous trucks. The EESS box, I always use KDS yellow label with matching yellow banded Temp sender unit...this is not a glow plug controller as some folks call it, the TSU replaced the GPC as the GPC was a weak point and failed often.
the TSU just sends a signal based on engine temp that say either turn on the glow plugs for 6-8 seconds or don't, quite simple. NOW, if your EESS is a GREEN Label, NO TSU is Required, the glow plugs cycle every time at startup regardless of engine temp, I don't see many green label box but I have a few in my stock I use for trouble shooting.

today I am seeing alot of the new S3 EESS boxes on eBay, these are the latest generation of box, I now have all my trucks running this box and they work quite nicely, no more glow plug afterglow where the gen bounces up and down for 2 mins after cold start, you can tell this box by the extra maint port on the front for Diag.equipment to plug into. I have several of these new boxes, they are either Nartron or KDS, each come with there own TSU but I have found any of the KDS or Narton TSUs work, they are backward compatible, again, TSU, Not GPC glow plug controller.

there is the SSI box, I would never use one of these, never had any luck, also, make sure you don't have one of the early versions where the glow plug connector plugs direct into this box, so you would 3 plugs on this box, 2 for the body wiring harness and one for the separate glow plug harness...theses boxes are a no no, they had a habit of actully starting the truck on its own, several motor pools had hmmwv's burn to the ground.

So now you have a good box, good glow plugs, now go clean off every ground on the truck....dash, gen, all the lights, starter, engine, all the gauges etc...now make up a grounding harness, you can buy them from Kascar or make your own.
think of an octopus, where the head of the octopus is the start point, in this case the engine, on the left rear cylinder is the ground termination, starting from there, run a wire to each of theses locations:
1. Generator ground
2. One of the bolts that mounts the EESS box
3.to the stud on the firewall that feeds all the instrument gauges, you should have cleaned this ground so you know where it is. You have to take the inst cluster out to get to it.the stud passes through to the engine area near the fuel filter, one of the body harness grounds terminates there.
4. The starter ground

All 4 of these connections can be terminated into on large 2/0 solderless connector that has a 3/8 lug to bolt up to the engine head. Now everything you need to run is grounded.
I have had trucks that would do all of the issues you guys post about fixed with just this harness, I have eaten my fair share of boxes as well, bad boxes will eat glow plugs, but the Kascar plugs have a thermo limiter like the civ AC 60 G glop lug, you can't burn them up, Wellman is the Mfg I see that the goverment gets there hmmwv glows from, every DRMO engine I have ever received be it 6.2, 6.5 or Turbo diesel all have the Wellman 24v GP's installed.

 

[houstonrealtor]

Hmm thanks for the post. Based off of that I don't have a TSU, instead I have a GPC. I've read that GPC's are often faulty. Wonder if I should just replace that instead of a $650 box???

 

[Retiredwarhorses]

Cute dog...lol, I have a great sense of humor, I just hate beating dead horses...this one is just bones.
but here goes....throw that box and the GPC in the trash can...you might not want to spend the money, but your truck is unreliable with out a reliable starting system...it's not a matter of if the older boxes will fail, it's a matter of when.
sound like your "when" has arrived.

As far as your Tach drive, it's for the ste/ice system...it's not for tachometer...tach's on the HMMWV run off the generator.

 

[houstonrealtor]

Thank you for the input as you seem to have a lot of knowledge on this system. I am trying my best to learn but it's a little difficult when the the ones with the knowledge try and use every acronym known to man (EESS, PCB, BOX, S3, GPC, GP, STE/ICE, TSU) when trying to explain something new to someone else. I own a very technical business and have to explain to customers what I am charging them for on a daily basis, I do this by using words that they would understand and giving examples instead of trying to show off my immense knowledge on the subject with acronyms that they're no familiar with and completely confusing them. I have read post after post of complaints about people not understanding this system yet I have not seen one person truly explain it so that a non "specialist" would understand it.

Not for the sake of this horse that has indeed been beaten to death can we please start explaining in layman's terms? I have no idea what an STE/ICE system is and after "googling" it I still have no idea. Also, why is it that the HMMWV has a "box" and civilian 6.2l motors don't? Is the box by-passable?

Please don't take offense to this post as I am only providing my point of view on this subject whether it be right or wrong it is my opinion and I am truly grateful for all the knowledge on this forum and everyone that contributes to the community.

 

[tigertank]

good point Houston they also like to say read the TM when u ask questions....while im sure the answers are in there but not all of us have the patience (ADD) or the time to struggle thru govt manuals retired warhorse is probably one of the best for answers he seems to know these vehicles inside and out

 

[houstonrealtor]

good point Houston they also like to say read the TM when u ask questions....while im sure the answers are in there but not all of us have the patience (ADD) or the time to struggle thru govt manuals retired warhorse is probably one of the best for answers he seems to know these vehicles inside and out

He definitely does know his stuff when it comes to these trucks. I agree about the TM's and they like to use a foreign language too. I hate to be so stupid but **** it's like everyone's talking to you in a different language when you ask a simple question.

 

[tomelroy]

"I own a very technical business and have to explain to customers what I am charging them for on a daily basis, I do this by using words that they would understand and giving examples instead of trying to show off my immense knowledge on the subject with acronyms that they're no familiar with and completely confusing them."

If you call 1-900-Warhorse he can explain this things with words you understand, but that is because you will be billed for his time! OR you could take your rig to his shop and he can fix it for you. Once he is done he can explain the charges......But you are on thin ice when the knowledge and time is free...iMHO

 

[DatGuyC]

The EESS (Engine Electrical Start System), PCB (Protective Control Box), BOX, S3(Smart Start System) all refer to the same thing, just different versions of it from different manufacturers. It is the box located under the dash on the drivers side that controls the power to the glow plugs (GP's). On the older hmmwv's there was also a "glow plug controller"(GPC) that screwed into the coolant crossover on the engine, but this has been later revised to just a temperature sensor unit(TSU) that tells the EESS when to turn on the glow plugs. The EESS cannot be bypassed because without it your glow plugs would not function.

 

[Lawdog734]

"I own a very technical business and have to explain to customers what I am charging them for on a daily basis, I do this by using words that they would understand and giving examples instead of trying to show off my immense knowledge on the subject with acronyms that they're no familiar with and completely confusing them."

If you call 1-900-Warhorse he can explain this things with words you understand, but that is because you will be billed for his time! OR you could take your rig to his shop and he can fix it for you. Once he is done he can explain the charges......But you are on thin ice when the knowledge and time is free...iMHO

I actually had a response done up that basically explained this, but deleted it without posting because I'm sure it would only have been taken the wrong way by some readers.

 

[tim292stro]

In summary, early HMMWV control boxes had a nasty problem with contact corrosion and water ingress under the hood. They are a replacement part when they fail - not worth it to repair (both in time and money).

Acronyms are shorhand, if you learn them it'll speed up conversation:
BOX = a 6-sided flat-sided polygon, AKA (Also Known As), prism, cube...
PCB = Protective Control Box, this box is a power protection unit, and is responsible for power distribution to other units, also it seems to be the unit most likely to set a HMMWV on fire due to the power levels it controls...
S3 = PCB "version S3", newest most current revision
GPC = Glow Plug Controller
TSU = Temperature Sending Unit, senses engine temperature different versions work with different GPC/EESS units - need to make sure they match, some trucks come with a combined GPC/TSU...
KDS = KDS Controls Incorporated, HMMWV component manufacturer - usually relates to the EESS unit(s) made by KDS
SSI = Signal Systems Incorporated, another HMMWV component manufacturer - usually relates to the EESS unit made by SSI
EESS = Engine Electrical Start System (basically a GPC ) - there is a 2-piece and 1-piece version of this, KDS makes both a 2-piece (older style) and 1-piece (newer style), SSI only makes a 1-piece.
STE = Simplified Test Equipment (think of this like the equivalent CUCV diagnostic port scanner, or a modern CAN-bus reader)
ICE-R = Internal Combustion Engine



[EDIT:] Meant to add this bulletin from Raytheon (MSWord) - it's a bulletin from Raytheon about the specific Wait-light issue you're seeing, replace your EESS with the mentioned NSNs (National Stock Number) and you're probably good to go. [/EDIT]

 

[Retiredwarhorses]

Thank you for the input as you seem to have a lot of knowledge on this system. I am trying my best to learn but it's a little difficult when the the ones with the knowledge try and use every acronym known to man (EESS, PCB, BOX, S3, GPC, GP, STE/ICE, TSU) when trying to explain something new to someone else. I own a very technical business and have to explain to customers what I am charging them for on a daily basis, I do this by using words that they would understand and giving examples instead of trying to show off my immense knowledge on the subject with acronyms that they're no familiar with and completely confusing them. I have read post after post of complaints about people not understanding this system yet I have not seen one person truly explain it so that a non "specialist" would understand it.

Not for the sake of this horse that has indeed been beaten to death can we please start explaining in layman's terms? I have no idea what an STE/ICE system is and after "googling" it I still have no idea. Also, why is it that the HMMWV has a "box" and civilian 6.2l motors don't? Is the box by-passable?

Please don't take offense to this post as I am only providing my point of view on this subject whether it be right or wrong it is my opinion and I am truly grateful for all the knowledge on this forum and everyone that contributes to the community.

im certainly not going to spend the time out of my work day to explain every acronym used here or in the military.
when I'm learning a new truck..M939's or M107x trucks...I have to figure out the same problem from a more knowledgable person...so I do research. I though my sticky did a pretty good job detailing the acronyms.
yoir going to be a better mechanic learning how to use the TM's...period. There are not civilian manuals for the most part, you bought a military vehicle, not a Chevy Silverado.
To many people post here wanting the quick answer...then don't post anything useful info once they get it.
I'm one person with 2 years backlog in the shop..if I'm postings its cuz I'm eating lunch, like right now, on the crapper, at the base in the RAMP shack or in my lounger....
i don't go to Rome and expect everyone I meet to speak English.....so consider yourself in a foreign country and learn the language.

Before I did this, I was a VoIP implementation egnineer for 25yrs...I know about explaining complex issues or engineering to less technical people. But I'm not in that business anymore, and 99% of my customers just want it fixed and don't care about the technical aspect of it.

 

[Retiredwarhorses]

I actually had a response done up that basically explained this, but deleted it without posting because I'm sure it would only have been taken the wrong way by some readers.

post away...this is not kindergarten, I thought we were all men. I See this same crap in my unit...please go do your Job, please get your work done...uhh, not me...17yrs army didn't teach me to say please, it taught me to get the Job done, without questioning.....things just ain't what they used to be.

 

[patracy]

He definitely does know his stuff when it comes to these trucks. I agree about the TM's and they like to use a foreign language too. I hate to be so stupid but **** it's like everyone's talking to you in a different language when you ask a simple question.

The TM's aren't that bad. You have to consider they were written for even a 18 year old to use. The thing is though, you have to start from the beginning. That's how they're structured. Skipping through them and you'll miss some information. Now, have I read every TM for my vehicles? No, hardly. But I have used them frequently and gained the ability to understand the structure to them. That has helped immensely. As for the acronyms, well that's just going to have to come down to search/memorizing to understand. Even I have to google things at times to understand what was said.

 

[tim292stro]

...I own a very technical business and have to explain to customers what I am charging them for on a daily basis...

You probably understand then how annoying this can be after a few years...

...Also, why is it that the HMMWV has a "box" and civilian 6.2l motors don't?...

They do, it's called a GPC/TSU.

...Is the box by-passable?...

Anything is possible if you are technically proficient - but like the realtor luxury item saying "if you have to ask, you probably..."

good point Houston they also like to say read the TM when u ask questions....while im sure the answers are in there but not all of us have the patience (ADD) or the time to struggle thru govt manuals retired warhorse is probably one of the best for answers he seems to know these vehicles inside and out

Probably not a good hobby if you have zero patience, and if it's your daily driver, might want to start looking for a replacement now.

...If you call 1-900-Warhorse he can explain this things with words you understand, but that is because you will be billed for his time!...

If you call any business and ask them to do their work for free, they will probably get a good laugh out of you I've worked with two types of people in my 20+ years of working, talkers and do-ers. RetiredWarHorses comes across to me as a do-er. Don't fight that about him, it's not a battle you're going to win, and it's not personal. Some of the most intelligent and effective people I've ever worked with were do-ers, and I learned a lot from them by asking the RIGHT questions (which took a ton of personal growth and learning to get to).

I'm certainly not going to spend the time out of my work day to explain every acronym used here or in the military. When I'm learning a new truck: M939's or M107x trucks... I have to figure out the same problem from a more knowledgeable person... so I do research. I thought my sticky did a pretty good job detailing the acronyms. You're going to be a better mechanic learning how to use the TM's period. There are not civilian manuals for the most part, you bought a military vehicle, not a Chevy Silverado...

This is actually some of the best advice you are ever going to get on this forum. IMHO too often people build their lives around relying on other people to do things for them, the generation after mine (born 1980) was the first generation I was cognizant of them not being able to do much of anything by themselves. Some are getting out of college with masters degrees now and STILL can't do anything themselves (fat load of good that degree did them). Be more self reliant and ask questions when you are truly stuck - do basic research first and you will be asking better questions less often, which will make answering them more appealing to the do-ers.

post away...this is not kindergarten, I thought we were all men. I See this same crap in my unit...please go do your Job, please get your work done...uhh, not me...17yrs army didn't teach me to say please, it taught me to get the Job done, without questioning.....things just ain't what they used to be.

Don't forget the women!!! (we are all adults, well there are some young people on here I'm aware of)

The TM's aren't that bad. You have to consider they were written for even a 18 year old to use. The thing is though, you have to start from the beginning. That's how they're structured. Skipping through them and you'll miss some information. Now, have I read every TM for my vehicles? No, hardly. But I have used them frequently and gained the ability to understand the structure to them. That has helped immensely. As for the acronyms, well that's just going to have to come down to search/memorizing to understand. Even I have to google things at times to understand what was said.

Yup, if a TM is too complicated for someone to handle, they should seriously consider taking it to a mechanic... That said, there is always going to be work involved in doing just about anything, unless your last name is Kardashian or Hilton - then you just need to open your wallet.

 

[ChevyC60]

Had this issue in one of two recently acquired M998's. One runs really good and one does not start.
BTW (by the why) the HMMWV is new to me. So on the non runner reconnected wires and repaired cut wires. The engine now turns over but no glow plug voltage. Swapped out the control module box (this box has so many Acronyms) and now had glow plug voltage. My question is the GPC ( glow plug controller card} in the control module box? Is there a schematic diagram for this control module box?

 

[houstonrealtor]

Had this issue in one of two recently acquired M998's. One runs really good and one does not start.
BTW (by the why) the HMMWV is new to me. So on the non runner reconnected wires and repaired cut wires. The engine now turns over but no glow plug voltage. Swapped out the control module box (this box has so many Acronyms) and now had glow plug voltage. My question is the GPC ( glow plug controller card} in the control module box? Is there a schematic diagram for this control module box?

I'm well aware of normal acronyms like BTW, I am talking about much more complicated items apparently with different names jdhfjdshfkjdshkfnre/ ejhfjbfjebefw systems...... But be warned, people get pissed if you have a question on this forum..... They are wayyyyy tooooo smart for your ignorance.....

 

[houstonrealtor]

Thanks everyone for their input. I agree with a lot of points and the the rest are completely silly. I am definitely a do-er and will ask 100000000x questions to anyone until I understand. I have very limited time to work on my HMMWV but I enjoy figuring it out and working on it. I have a great deal of experience with drive-lines, suspensions, transmissions, transfer-cases, auxiliary transmissions, air systems, hydraulic systems, ptos etc on diesel trucks (primarily big rigs) however I have no experience on the engine side. If you just want to showcase your acronym collection then bitch about people not understanding you then maybe its best not to respond to their post?!?!?! Like you saved yourself that much time by trying to make that **** confusing, probably the same people that write Merry xmas or happy bday (good thing you shortened that for the sake of saving time). I could read the whole TM (which I have) but I feel like this is a community of people with the same interest/hobby and I thought I may be more successful to ask people with experience what their thoughts are. Who here get goes to law school or med school so they can understand the jargon??? I myself just ask my attorney or Doctor what I need to do and they make it make sense. Please don't take any of this personal, I admire everyone input on this forum and enjoy reading all these post. Please be patient with dumb folks like me or if it is just too frustrating for a person with such a high IQ then please skip past my post.

 

[Retiredwarhorses]

Don't worry Houston...I will make it a point not to reply to any of your posts for fear of upsetting you with an acronym...and I'm quite sure others may very well feel the same.
I guess we should all stop using acronyms like fedex, IRS, FBI, DLA, CIA, DODAC,UPS, TACOM, GOV Liq, GP...all so we can appease you....if you don't understand an acronym, ask for clarification, don't sit an whine with your keyboard that you have somehow been single out and then be a condescending in your reply....it's just not the case.
You sir asked a question....we sir answered it, you just didn't like the answer as it did not fit into your knowledge base.