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Discussion Starter · #1 ·
Hello,

New here but NOT new to these trucks. Bought a 2006 2500HD with a bone stock LLY Duramax about 10 months ago. Driven daily with no issues. The truck has 200K on the odometer. Yesterday I drove it to the store and when I got home I was backing it in the driveway and it stalled (Allison 6 speed, no reason I could have stalled it). The engine just cut off, I hit the key to re-start it, it spun over for about 2 seconds, started and cut off again. I let it roll into the drive way and popped the hood, nothing unusual found. Got back in to restart it and nothing, no crank-no start. The gauges slam to the left and only the VOLTS gauge seems to be working. I get NO engine check light, no Glow Plug light, I now get a "Braking System Requires Servicing" on the info display. The batteries are good. Security System works fine, radio ...... all that stuff. I get no codes from my OBD reader because it cannot communicate, so it appears the ECM is not powering up, checked all fuses, swapped relays, all the normal stuff. Pulled the left front wheel, inner fender panel to expose wiring and ECM. It all looks great, this was a well maintained truck, doubt it's ever been off road ........... I have looked at all wiring from transmission, ECM, TCM, Glow lug controller ............. at one attempt to crank the truck it did spin the engine over ..... but it was delayed by about 10 seconds, meaning I turned the key, and nothing them all by its self the starter cranked the engine for maybe 2 seconds .......which I thought was strange. I am looking for an ECM and engine diagram set for this 2006 LLY ECM?? Starter is good removed/replaced after bench checking it. Can jump the starter relay (under hood fuse/relay box) and starter will spin the engine. NOT a starter. Inspected all battery cable to start with ...... all good. Never Jump started it or anything as I have read about issues with that.

I have read about all the different places to look for wiring damage, after about 8 hours of taking things apart I have found nothing. No open fuses ....... just nothing. I traced out most of the DC grounds and cleaned/re-installed. Any help?? An ECM Pin-OUT ? TCM Pin-Out?? Engine harness diagram?...... need to look and see where I am missing Power / Ground.

Any chance one of the other controllers is killing the communications to the OBD?

Thanks in advance,
Les
 

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I would start with ground on frame under drivers door famous GM ground failure. There's 1 behind each fog light, couple on bottom of engine near front. Then find any under hood. Remove wirewheel clean, smear Dielectric grease on all contact points and reinstall. You might get lucky, otherwise might be starter. Try Jumpstart and manytimes the extra juice will kick over the bad starter

Guess maybe you got most of that. I would strongly suggest looking at the crank position sensor. Upper left of water pump and L side of fan clutch pulley as you're looking at it. Can suddenly fail causing all kinds of no start, misfires, running rough. The camshaft sensor is another common one. Sometimes a sensor relearn with a scan tool will fix it...maybe temporarily, maybe for 2yrs. Oddly enough I just threw one in last night with my water pump. Very hard to test em. Or know without a scope of some sort to view signal.

Only use GM or the Isuzu is probably ok. Nothing else

Check wiring behind drivers wheel well, a guy made a vid about wires rubbing on the wheel well through and no start.
Check all harnesses for wires rubbing. I've added slit heater hose and split loom with zip ties all over sharp corners and rub marks, virtually every harness is rubbing on something. There's another bad spot under large intake elbow in center right side. I seen the black plastic intake had rubbed through the split loom already and started on wires. I ziptied a piece of rubber over it.

South Main Auto on YouTube, Eric is a genius at finding tracing and diagnosing issues on vehicles. Pretty sure he had Duramax's in too cuz he said he don't usually work on em.
 

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Discussion Starter · #3 ·
Good Morning,

Thanks for the reply. I have done just that, I decided to engage the starter via the relay module a bunch of times, I get a rock solid spin of the starter each time I engage it.

It's the dash panel that makes me believe it's the ECM issue (power or Ground) because I do not get the normal pre-start indications (Glow Plug Light, Check Engine Light, no engine temp reading when it was still 210 degrees after driving it, no fuel gauge movement as it's full of fuel). The "BRAKE SYSTEM REQUIRES SERVICE" message on the info display has me puzzled too ...... it's all related somehow, just gotta figure out how.

I am an engineer for Caterpillar Electric Power Systems, I have some resources but NOT with GM really ........ never had to, have always had good service til now. I am about to learn something or look stupid ...LOL

I am going through all the standard stuff ...... just reaching out. Thank you for responding, will look at those grounding points. I have experience with controllers failing in a way that takes multiple sub-ecms offline, can I unplug the ABS controller, TCM and others one at a time and see if I can at least get a code from the ECM??

Looking for engine diagram and ECM pin out if you have any resources for that ..... thank you sir!
 

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I just had an issue with my 2006 LLY where the ignition would randomly power up and the truck would not shut off. Turned off key, radio, hvac, gauges, all went down but engine stayed running. In the little info box under the speedo said Service 4wd, Service ABS, and a couple other things I cant remember. Like you I checked all wiring and what not. What ended up being the problem was the main fuse panel. GM has had a lot of issues with the fuse panel and internal corrosion/ physical component damage. Its like a sandwich so to speak. There is a layer underneath where all your fuses and relays go. Then below that is where all the wiring harnesses plug in. Like you my issue just popped up out of nowhere for no given reason. Might be something to consider. I am going to pry mine apart here soon and see exactly what goes on in between the two halves of the fuse panel.
 

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Discussion Starter · #6 ·
Yes there's a ton of electrical diagram in on GM UPFITTER - Body Builder Manuals
Great Resource, hopefully I can get this figured out.
The initial check out showed nothing broken loose under the main fuse panel (under hood), fuses good, relays good.
Pulled the ECM connectors C1-C2, did some initial checks (Power-Ground 3 of each, pins 1, 3,5 and 2,4,6 on C2). My initial thought was ECM not powering up, but now I can tell it is getting power however there are several inputs when the key is in run/start mode that need to be checked. In between rain/storms I hope to get back into it today.

The lack of an ENGINE CHECK light and Glow Plug light point to the ECM NOT getting a run input, watched a million YOUTUBE video's and saw some good things to check, having an accurate wiring diagram helps take the guess work out of the work.

I may move it into my airplane hanger today, so I can work on it regardless of weather. NOT running it's a beast to move.

Thanks for the good tip ........

Les
 

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Discussion Starter · #7 ·
Great Resource, hopefully I can get this figured out.
The initial check out showed nothing broken loose under the main fuse panel (under hood), fuses good, relays good.
Pulled the ECM connectors C1-C2, did some initial checks (Power-Ground 3 of each, pins 1, 3,5 and 2,4,6 on C2). My initial thought was ECM not powering up, but now I can tell it is getting power however there are several inputs when the key is in run/start mode that need to be checked. In between rain/storms I hope to get back into it today.

The lack of an ENGINE CHECK light and Glow Plug light point to the ECM NOT getting a run input, watched a million YOUTUBE video's and saw some good things to check, having an accurate wiring diagram helps take the guess work out of the work.

I may move it into my airplane hanger today, so I can work on it regardless of weather. NOT running it's a beast to move.

Thanks for the good tip ........

Les
Well it's Sunday, Worked on this thing all day ......... took just about every connector/plug apart ..... I crawled under the truck and inspected the Transmission wiring ..... and found nothing. I re tested all ecm power inputs and ground, I did the same with the TCM, checked for continuity between pins 69 and 9, that was good. I have the PRNDM light under the tranny position indicator ......I have the correct voltage where it's are supposed to be ......grounds too. I jumped out the Park/Neutral switch on the Allison 6 speed incase it thinks it's not in park ..... no change. I jumped out the starter relay 10 times to give the starter and solenoid a work out, it spins the engine over with no trouble.

To recap;

I drove the truck to the store and when I pulled up in front of my driveway I stopped and planned to back in the driveway, the trucked stumbled and cut off. I cussed a bit, and put the truck in park, turned the key to restart, it fired up and I put it in reverse ....... got in the driveway and it stalled again. I put it in park ....attempted a restart, NOTHING! No Crank No Start!

Everything inside works, radio, lights ....blower .......all normal. What's NOT normal is the Check Engine Light does NOT come on, The Wait to start/Glow Plug Light does NOT come on, The ABS light is on ......... ALL gauges except the battery voltage gauge does NOT work. If I turn the key they slam to the left then go to zero. Fuel gauge is at empty but the tank is full. I have a EDGE programmer and it does NOT see the ECM or TCM ..... says NO Comms! I can feel a very slight clunk in the floor of the truck when I turn the key to start, figured it was a fuel pump or ABS module maybe. It's NOT a starter or Batteries .......Batteries load tested, starter tested plus I can spin the engine over by jumping out the start relay all day long!

I have had folks say it's the TCM .... but I cannot prove that ..... others says it's an ECM for sure. I cannot prove that either .......... I feel it's a wire maybe ........ but all required Power/Grounds are where they are supposed to be and load tested.

I need a Tech II or Bosch EDS 625 where I can see all the inputs active and in the proper sequence LIVE when I turn the key. At $1800 I just can't justify that at this point ..... maybe I can rent one. I talked to the Service Manager at the local dealership who is a friend, he suggested letting the shop guys look at it and give them a NOT-TO-EXCEED dollar amount for troubleshooting ........ I can buy a TCM for about $375 programmed to my VIN ..... but I just can't prove mines bad ..... everything I have read says my TCM is good based on limited troubleshooting.

As mentioned in my initial post, it did spin the starter over but with a 15 second delay one time ....... maybe that was my wire burning up completely .... LOL .... just wish I could find it!

Any thoughts or guidance appreciated ....... this is just too nice of a truck to sit here broke!

Happy Easter guys/gals

Les
 

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Discussion Starter · #8 ·
Well it's Sunday, Worked on this thing all day ......... took just about every connector/plug apart ..... I crawled under the truck and inspected the Transmission wiring ..... and found nothing. I re tested all ecm power inputs and ground, I did the same with the TCM, checked for continuity between pins 69 and 9, that was good. I have the PRNDM light under the tranny position indicator ......I have the correct voltage where it's are supposed to be ......grounds too. I jumped out the Park/Neutral switch on the Allison 6 speed incase it thinks it's not in park ..... no change. I jumped out the starter relay 10 times to give the starter and solenoid a work out, it spins the engine over with no trouble.

To recap;

I drove the truck to the store and when I pulled up in front of my driveway I stopped and planned to back in the driveway, the trucked stumbled and cut off. I cussed a bit, and put the truck in park, turned the key to restart, it fired up and I put it in reverse ....... got in the driveway and it stalled again. I put it in park ....attempted a restart, NOTHING! No Crank No Start!

Everything inside works, radio, lights ....blower .......all normal. What's NOT normal is the Check Engine Light does NOT come on, The Wait to start/Glow Plug Light does NOT come on, The ABS light is on ......... ALL gauges except the battery voltage gauge does NOT work. If I turn the key they slam to the left then go to zero. Fuel gauge is at empty but the tank is full. I have a EDGE programmer and it does NOT see the ECM or TCM ..... says NO Comms! I can feel a very slight clunk in the floor of the truck when I turn the key to start, figured it was a fuel pump or ABS module maybe. It's NOT a starter or Batteries .......Batteries load tested, starter tested plus I can spin the engine over by jumping out the start relay all day long!

I have had folks say it's the TCM .... but I cannot prove that ..... others says it's an ECM for sure. I cannot prove that either .......... I feel it's a wire maybe ........ but all required Power/Grounds are where they are supposed to be and load tested.

I need a Tech II or Bosch EDS 625 where I can see all the inputs active and in the proper sequence LIVE when I turn the key. At $1800 I just can't justify that at this point ..... maybe I can rent one. I talked to the Service Manager at the local dealership who is a friend, he suggested letting the shop guys look at it and give them a NOT-TO-EXCEED dollar amount for troubleshooting ........ I can buy a TCM for about $375 programmed to my VIN ..... but I just can't prove mines bad ..... everything I have read says my TCM is good based on limited troubleshooting.

As mentioned in my initial post, it did spin the starter over but with a 15 second delay one time ....... maybe that was my wire burning up completely .... LOL .... just wish I could find it!

Any thoughts or guidance appreciated ....... this is just too nice of a truck to sit here broke!

Happy Easter guys/gals

Les
 

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When you look at your copy of the ELECTRICAL MANUAL for your truck, pay particular attention to the GMLAN system sections. GMLAN has 2 basic circuits, high and slow speeds. Generally, the high side lets your engine start and run and your truck to drive/brake, slow speed covers almost all the other electrical functions in the truck. When your check engine light does not light up at key on, it means that the communication with the ECM is not present, and if your ECM isn't communicating, your truck isn't starting or running.

Any device on the lan can bring the entire lan down - causing communication failure. One of the required components is the ABS module, and those often lose their ground and IF that is the problem, it is pretty easy to solve. However, it may also require a new ABS module if the module itself has failed. So, find the problem that causes the communication failure with the ECM communication. If you have a scan tool that communicates with at least most of your computers in the truck, you can see all the modules that aren't communicating and thus where you need to focus your efforts.

Having said this, I am just guessing what your exact problem is. I can't see it or test it, so in all reality, I'm just guessing, and that's the best I can do.
 

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Discussion Starter · #10 ·
When you look at your copy of the ELECTRICAL MANUAL for your truck, pay particular attention to the GMLAN system sections. GMLAN has 2 basic circuits, high and slow speeds. Generally, the high side lets your engine start and run and your truck to drive/brake, slow speed covers almost all the other electrical functions in the truck. When your check engine light does not light up at key on, it means that the communication with the ECM is not present, and if your ECM isn't communicating, your truck isn't starting or running.

Any device on the lan can bring the entire lan down - causing communication failure. One of the required components is the ABS module, and those often lose their ground and IF that is the problem, it is pretty easy to solve. However, it may also require a new ABS module if the module itself has failed. So, find the problem that causes the communication failure with the ECM communication. If you have a scan tool that communicates with at least most of your computers in the truck, you can see all the modules that aren't communicating and thus where you need to focus your efforts.

Having said this, I am just guessing what your exact problem is. I can't see it or test it, so in all reality, I'm just guessing, and that's the best I can do.
Ron,
Thank you sir, very informative post ...... that's kind of what I have been looking for ...... what's required from the system components for the ECM to allow a start. This truck has all the bells & Whistles and there is alot going on!

I did check the ABS module electrical connections, removed them, verified power and ground ......but I did not know that was a required device on the network to get a start and run ........ good to know.

The reason I don't want to jump on the ECM or ECM's (bad) bandwagon is because I have various parts of these systems working, and can verify they at least power up and issue basic commands. As an example the ECM has 2 parts, one half that is powered/running all the time ..... and part of it is running only when a start is needed. BUT ... the instruments for example should power up when the ignition key is turned on .... even if the engine is NOT started, so I see a problem there ...... I have no instrumentation activity ..... battery gauge only, also the Check Engine light and Wait-to-start/Glow Plug light ...... I never get them, and it originates from the ECM ..... so I feel like I have a communication issue and without a scan tool that is bi-directional I can't see what is online communicating and what's not. I currently have no communication ........then ECM power up relay under the hood is an example of why I think my ECM is good, it does pickup and send power to the engine run side of the ECM, there are 5 or 6 IGNITION + signals and they are all present ...... main power and grounds, 1,3,5 and 2,4,6 .......plus the switched inputs ..... all good.

I looked at the Transmission signals TCM, when I put the gear selector in manual I can hit the UP/Down button and watch the indications on the dash showing it selecting gears 1 thru 6, now that is not actually gears switching but if the TCM was bad I am told that would do nothing ...... so I have at least some basic functionality showing its powering up and running ................

I agree, I need to look deeper into the loss of comms issue ..... just figured it would be because of something NOT getting power/ground ...... it's so easy to just throw parts at the truck in a situation like this .......

Thanks for the response sir ...... that was all good info! I am looking into the ABS controller deeper tomorrow after work. I have got to get this fixed or my wife will want to use my new GMC 2500HD to pull her horse trailer this weekend ...... I ain't having that .... even if I gotta sleep on the couch .... LMAO.

I found a mobile guy who is local that said he would come by and hook his TECH II up and troubleshoot only ..... that may give me direction .......!! He said if I was flexible he would work with me .... use me for fill-in work between jobs.
My local GM dealership has also agreed to help, by the hour ... LOL

I am either going to look dumb or learn something here, I am good either way .......

If you think of anything else please reach out!

Best Regards,

Les
 

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Discussion Starter · #11 ·
WELL,

I have NOT moved an inch forward since starting this whole Issue ...... doing some thinking I think I need to address the NO COMMUNICATION issue first. Since I have found no wiring issues ( I have done everything but pull the wiring harness out, but have continuity tested everything end to end ). It will be hard to move forward without communications at the ALDL (OBDII Port).

I have power there ...... and yes the cigarette lighter plug works. The batteries are good, I have a $1300 battery tester on my service truck, batteries good ...... starter good and proven good ..... if the starter relay is jumped pin 30 to 87 it will spin the starter over until the batteries are exhausted ...... Just getting that out of the way!

How would the experts think I should proceed?? I thought about taking all controllers/devices on the com buss loose and just have the ECM connected incase something is trashing the signal ...... good idea? I have no dash gauges working except the Battery gauge ...... loss of GM high high/low speed data buss ........I have a constant ABS light when the ignition is switched on .... and a BRAKE SERVICE REQUIRED on the digital display (DIC I think??). I am missing the Check-Engine and Wait-to-Start (Glow Plug) lights ..........no open fuses or bad relays .......

I borrowed a TECH II and I have no comms with any devices (TCM, BCM, ECM, ABS). Would like to get someone's input here .... Before I buy a replacement ECM that I may or may not need.

Thank you in advance ........

Les
 

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Discussion Starter · #13 ·
Ron,

Thank you for providing that document. Long work week but now I am back to working on the truck.

If trucks were fueled by POLLEN, we could drive forever ........ sneezing my head off ...LOL

So I did not post this but last week before I went on business travel I decided to concentrate on the comm (DLC) issue,
so measuring across the CAN Hi and CAN lo lines pin 6 and 14 on the DLC I have 60 ohms resistance, so the network is basically intact (both 120 ohm termination resistors) and with one of those 120 resistors being in the ECM the CAN Bus could communicate with something if the network was active ...... I put a scope on the DLC and there is NO ACTIVITY. I would expect at least one of the devices (TCM, BCM, ABS, Door modules, instrument cluster) to be attempting to communicate. That tells me the CAN Bus is compromised by a device that is shunting the communication, so today I will start unplugging modules to try and get something to talk .........

I also measured the CAN Hi to ground and get 1.8 VDC and the CAN Lo to ground and I get 1.6 VDC ........it should be about 2.5vdc or better on HI and Lo ......approximately anyway, so something is killing the signal ....... and based on some other things I am ordering an ECM most likely......

I will unplug the ECM later today and see if that allows the other devices to communicate ........ and I will bet my CAN Hi and Lo voltage to ground recovers to a normal range.

I am looking at the document you provided me (Thank You), it takes you down the same path I am taking. I work for CATERPILLAR on large marine engines ( both Generator and propulsion ), the engines are the size of a house ...... and we use J1939 CAN Bus on everything so I am very comfortable with it .........admittedly working on an automobile is a challenge as everything component wise is hard to access compared to the big things I work on .......... but in other ways it's easier too, they do pack a lot of crap in tight places in vehicles ........geezzz

I got an email yesterday saying JUST Replace the ECM already ........... right! Must have been a young person with Mom and dads money ....LOL

So one might think that I should just pull the ECM and replace it ...... well for one it's NOT returnable. Secondly if I don't try and attempt to find the mode of failure I could plug in a new part and burn it up too! It's one thing when a bazillion dollar corporation is paying for the parts ... but another when it's coming out of my pocket. I am sure everyone gets that.

A new ECM programmed to my VIN is just south of $600 delivered (with a warranty), and I don't mind paying a reputable vendor who stands behind their parts. I found a used one for $250 ..... no warranty, no return .....so no thanks! He could send me some old burned up core and I have no recourse!

If anyone has a source for a reman/refurb or new ECM programmed to my VIN please share ..... I will research the parts source a little more in-depth over the weekend. I got the $600 price from a buddy who works at a GM dealership, he told me where they purchase ECM replacements from that GM no longer supports. $600 is my cost with shipping.

Again, Thank you Ron ..... you and a few others have been very helpful .... GLAD YOU GUYS ARE OUT THERE!

Just want to thank those who keep this forum working ...... it is very helpful if you have time and patience to do your own service work .........

I will keep this updated until my issue is resolved!
 

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Discussion Starter · #14 ·
So today I took the ECM connectors off and rechecked the voltage to ground on the Can Bus or GMlan whatever they really want to call it. CAN bus Hi to ground voltage jumped up to 2.56 volts from 1.8vdc and CAN bus Lo to ground jumped up to 2.45 volts from 1.6vdc ....... an improvement for sure. This points at the ECM directly ..... my guess is some portions of the ECM are working ...... as ALL grounds and Voltages are present, as well as the 5 vdc references for the sensors etc. I do show 60 ohms when measuring across CAN Buss Hi and Lo, so the wiring is intact (GMLAN). No Communication ......NATA!

I did not put my scope on the CAN Bus to see if something was there as far as data ...... but after reading a document I found on this forum from 3 years ago it all made since. It seems that I originally understood all modules talked on the Can Bus or GMLAN .........and I knew there was a serial bus (Class 2) but I did not know which devices were on what bus, that is due to my 2006 LLY being in the middle of a major change hardware wise, 2006 LLY with the Bosch ECM are not easy to find. I looked at many documents and drawings which claim to for a 2006 LLY or LBZ and they were actually a 2005 with the 3 connector Delfi ECM.

ANYWAY .......I figured it was very low priority stuff like windows, door locks, radio, AC, alarm system on the Class 2 buss. This document I found (I will post it) explained that the only devices on CAN Bus were the modules dealing with the engine/transmission. Everything else was on the slower serial bus, starting in 2008 I believe I read was when everything went to one High Speed Bus, Can Bus (GMLAN), 2006 they actually changed the name from CAN Bus to GMLAN .......it's still CAN ......I am sure the name changes revolved around dollars (licenses, trade mark crap).

With that said, all I would see on my CAN Bus if all was well would be GPCM, TCM and ECM, The slower Class 2 data also if you were looking for it with a scan tool. Remember the FICM does not exist on my 2006 model with the LLY or LBZ as it's it's part of the ECM now. So my instrument panel data (which I was missing) is actually on the slower serial bus (Class 2 bus). Well the ECM partial failure in the communication department explains why I lost my instruments, and ABS .... that slower bus also comes from the ECM. The ECM has both the GMLAN (Can Buss) and the slower serial Class 2 bus flowing through it ........ I may have the terminology wonky but I hope you can figure it out ..... the ECM sits right in the middle of most of the communication dealing with the engine and Class 2 buss, loose the communication portion (or all of it) of the ECM and you loose 75% of all communication, and the engine won't start or run ........... the ECM currently in it's limited operational state is looking for signals from the TCM and GPCM to allow a start ............ no Joy!

I have to give credit where credit is due ...... the guys at Flagship One in NY assisted me in understanding exactly what the ECM did in my specific case, I could see from the drawings but could NOT even guess at the programming. I contacted them as a replacement ECM provider and their tech support connected the dots as far as what a 2006-2007 LLY and LBZ ECM specifically did, the detailed stuff the average mechanic would not know .... but would guess at, and what it needed to run ...... they also said my failure was NOT common and it would have been hard to definitively troubleshoot ....... but experience would have helped someone guess. I guessed ECM or TCM ...... so I was close early on, but I did not want to spend a ton of money on a 2006, the dealer would have milked it for several days ....then threw parts at it.

So far I have $600 in it and my time.......I can live with that. I love this truck, My butt has been in that seat for years ...... she has been good to me and my family .....and was my service work truck before that ..... we have history!

I had a 32 foot tag along camper behind it going up/through the NC mountains around Cherokee, my buddy had a 6.7 Power Stroke with a 24 foot camper behind him ...... calling me on my cell yelling slow that thing down, I cannot keep up! LMAO ........

Anyway ..........

I did purchase an ECM, but their help was not connected to the sale, but it went a long way in helping me decide where to purchase an ECM. They were great, the ECM was about $550 with programming to my VIN, I tried to get an LBZ program but they were not able to do that because of the EPA agreement they have. If I had an actual VIN from a 2006-2007 LBZ they could have done it. No problem I may have a copy of the LBZ tune I can re download when it's running. I think I did that to my son's truck .......

I always wondered why the 2003-2007 Duramax's took so long to download a tune, now I know, they still use the CLASS 2 serial bus to perform the downloads, it wasn't until 2008 and up that the system went entirely High Speed GMLAN or CAN bus ..... which was faster. My truck was stock LLY, but I have flashed several tunes for my son and his buddies .............. I always said if I ever had to replace the ECM I would give her some power ..............

Anyway, I could never understand the "Brake Service Required" message on the Message HID the instant this all happened ..... now I have a better idea ......when the ECM failed it took out both the high speed and slow speed bus, the ABS is on the Class 2 buss, the ECM lost com with the ABS controller and I was looking for it on CAN Bus. That is what the "FLAGSHIP One" guys says was NOT a common failure mode ....... normally you loose the injector drivers because of a wiring harness short to ground ....... or memory ..... but not communication from the ECM. Normally another device on the network shunts the CAN Bus to ground ... killing communication.

Just glad it failed in front of my house ...........

Anyway, I purchased an ECM and they say it takes 3 to 5 days to arrive, they won't program one until Monday I am sure ....... so I hope to have her running next weekend maybe ...... in the mean time I will beef up the split loom wrap on all the possible failure points ...... change the oil ...... and wait for my ECM.

I will update this soon ..... the FlagShip One Inc. guys were awesome 516-340-0636, they have a webpage too. They had a guy chatting with me when I got to there webpage ....... and they called me back to ask if I needed help ....that's when tech support got so helpful. I also liked that I could pay via PayPal, if something went south with the purchase PayPal has always been good about getting my money back ............ can't be too careful these days ..... No Core charge and they will repair your original ECM ....... if you want to go that route.

Webpage is fs1inc.com
Phone is 516-340-0636

If the thing actually runs and is healthy I will contact them and ask to with the PREZ and brag a little ...... they were helpful, NOT cheap ... great warranty, but a really really helpful tech support! Good Business model ..... make the customer want to spend more money ...... and give him something for it.

More soon!
Thanks again!
 

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I chased electrical grimlens in my LLY for a month. It ran fine but was in a different world every time I started it. Turned out to be the darn aftermarket radio interface. One day I got frustrated and just started unplugging things. I too spent hours under the dash and hood checking grounds and connectors. Turned out a $40 scoshe interface locked it up.
 
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