Standalone Tuning

[SpartanSupreme]

So, I've been having trouble doing a standalone tune on a 2008 LMM. Is it even possible with the standard tuning software, or do you need to have some kind of additional patch download or something?

The only thing I did so far is disable the security sytem by setting it to none. Should that be enough as far as the programming is concerned? Or does it require something else to disable the interlocking that the system has with the BCM and other modules?

I already have the ecu wiring harness reworked, so that I just have a constant hot, and then a switch for the ignition power to the ecu. Then I have a separate switch to engage the starter motor. Any help would be much appreciated, I've been doing alot of research, but I haven't found any definitive ansers.

[kidturbo]

You need to tie the serial data wire off ecm in with your key on hots. Rest of your setup sounds correct. Should run fine in stand alone mode then.

Sent from my SAMSUNG-SM-G890A using Tapatalk

[SpartanSupreme]

Wow, thanks for the quick response. Just to clarify though, I assume you're referring to the dark blue "Accessory Wake-Up Serial Data" wire, right?

There's also the "High Speed GM Lan Serial Data Bus." But that one is a two wire tan and tan/black.

[kidturbo]

Yeah the blue wake up wire is the one ya want.

Cheers

Sent from my SAMSUNG-SM-G890A using Tapatalk

[SpartanSupreme]

Here's an update in case anyone was curious. I was staying out of the cold, and just now got back to work on it.

I still haven't got it working, so I'm not sure if I have another issue or what. Here's a list of all the 12v constant and 12v ignition wires. I used 2 Blue Sea fuse blocks, with screw terminals, so its pretty easy to be sure that everything is right.

12V Constant:
10amp - ECM Batt
10amp - TCM Batt
20amp - Fuel Priming Pump (only the Express/Savana vans have these, as far as I know)
20amp - Data Link Connector
10amp - Instrument Cluster

12V Ignition:
30amp - ECM (powertrain)
10amp - ECM (powertrain)
15amp - ECM (ignition) **Plus ECM accessory wake up wire**
15amp - Transmission
15amp - TCM (ignition) **Plus TCM accessory wake up wire**
10amp - Glowplug Module (ignition) **Plus GPCM accessory wake up wire**
15amp - Mass Air Flow sensor
10amp - Instrument Cluster (ignition)

I traced out the wires out as I disconnected them, but I also found all the computer pinouts from an upfitter manual. GMupfitter.com

I hooked the instrument cluster back up for now, basically just so I could see the wait to start indicator. I'm not sure if its possible to use the gauge displays in a standalone system. It seems like all that information gets transmitted on the dark green "Low Speed GMLAN" wire. And that comes from the Body Control Module, not the ECM. So I guess I would need to get some aftermarket CAN bus gauges or something.

I've tried reflashing a few times, but the security light just keeps coming on, so I don't know what the deal is. For some reason, it also has codes saying the fuel injector data is incorrect now. At this point it just seems like its been a huge waste of time and money. The goal was to just have a simple engine-computer relationship. Non of the extra body control module nonsense, and all the unused wires. I'm an electrician, so I prefer to have hardwired, segregated accessories. There's no need for a computer to get involved with simple operations like headlights and turn signals. It just adds unnecessary complexities. And I don't need any of the "retained accessory power" nonsense either. But apparently, getting rid of those complexities is an even more complex issue. Why can't they just be good engineers and KEEP IT SIMPLE STUPID! lol

[jeeper]

Not sure if you're monitoring this but I am in the process of doing something similar I think. Did you ever get it going?

I'm trying to do a 2006 LBZ using just the engine and transmission computers. I have the under hood wiring harness for the ECU and TCM only. I have wired in an OBDII port and can talk to the ECU on the stand just fine.

I have removed VATS and tested the computer in my sons LBZ and it runs great. I also put a mild tune on it and that works well also. But when I connect up to my wiring and try to start the engine on the stand it will not fire up. I'm not sure what I'm missing?

[SpartanSupreme]

I should have posted an update, but yes, I did get it running. Once I followed kidturbos help, I had everything I needed.

After spending some more time pulling my hair out, I found one of the engine wiring harnesses just had a loose connection. Secured it tight with some zip ties, and it started right up.

I was still having some issues with it running in reduced power mode. But I think that was because I was missing the emmissions components. They can be deleted in the programming, but I never got that far. Ended up abandoning the project and parting everything out.

I'm not sure how much stuff could be different on the LBZ. How are you switching all the ignition circuits? Are you just trying to directly power the coil of existing relays?

I know on the LMM, there was a Powertrain Relay, and an Ignition relay, and if I remember right, one of them was ground switched for some reason

[jeeper]

I should have posted an update, but yes, I did get it running.
I'm not sure how much stuff could be different on the LBZ. How are you switching all the ignition circuits? Are you just trying to directly power the coil of existing relays?

I know on the LMM, there was a Powertrain Relay, and an Ignition relay, and if I remember right, one of them was ground switched for some reason

I don't have any relays with my harness. I got the harness without any fuse blocks or relay stuff. It only had the plug which I believe is called C2. It had the orange and pink wires on it. For now I tied all the orange wires to battery positive and I took all the pink wires to a toggle switch that I can use to simulate the ignition switch. I don't have a serial data wire attached to the switch though. I guess I need to find the LBZ schematic and determine what wire that is and get it attached as well?

[jeeper]

I found a pinout for a 2007 Lmm. I have read it is the same as the 2006 LBZ. When I compare the 2008 LMM it shows pin 56 on the 58 pin connector as D-Bu Accessory Wake-Up whereas in 2007 pin 56 of the same connector is pink ignition voltage. I already have that tied into my toggle switch...

I'm still trying to get this fired up but am missing something I guess.

[kidturbo]

Hi everyone. Haven't been online much in past few days, so just catching up.

To verify those serial-data wake up pins, check EFILIVE Bernch Harness Wiring Diagrams. That's been my fall back on the question for long while. The only thing I recall,, and don't quote me, different between LBZ and lmm of importance is a couple MAF or MAP pins. Been a while, but last one that stumped me.

I have a bench harness downstairs I can always verify if you need something. They will fire without any relays as so long as correct pins are powered, however not recommended ya run 35 amps through any std ignition switch. Also have seen a slick trick using Factory fuse block, if you have that and a chassis harness laying around.

Feel free to p.m. me for phone or Skype if you'd like to chat. I've got plenty of pictures and diagrams of different harnesses, but scattered on over a few sites..



Sent from my SAMSUNG-SM-G890A using Tapatalk

[jeeper]

Thanks kidturbo. I really appreciate the help. I may end up sending a PM but I'll post the questions here just in case any information given may help someone else in the future. These forums are invaluable for that reason. Much information has already been shared and PMs are not visible to everyone.

I never bothered looking at the bench harness tutorial until you pointed it out. I think that I already have the harness set up for the ECM and TCM. I will double check to be sure I have power on those pins and report back.

So just to be sure I don't forget to ask, since I am not using a BCM and the PCM is not receiving a signal from it to start the engine am I relying on the crank and cam sensors seeing the engine turning over? It works this way on a LS1B ecu just fine. I did a LS swap into a Jeep and it would start just fine when I cranked the engine over from the Jeep ignition switch which was separate from the GM PCM.

[kidturbo]

Your correct, without a BCM, nothing to tell it "key-on" switch on PTR by ground signal from ECM. Same thing with cranking. All that is handled by HSGMLAN canbus messages after about 04 or so in gasssrs and 06 on the Dmax. With VATS disabled, I've triggered those relays via cabbus and a laptop.

Same protocols used accross all GM after those years up to about 18. Beside the Vette, but I believe that OS difference is documented here. Short, ya can drop a Durmax engine and Allison trans in a Camaro, it will run happy as if rolled off Detroit's assembly line. But since we ain't using a BCM, we just power up ECM and all other modules as if you shorted the relays in the fuse block.. Would be super easy to steal a car, so GM added VATS to solve that issue. History lesson over..

So with VATS disabled, they run fine hot wired. However, they have no verification of cranking. So basically it sees crank cam signals incoming, says wow driver must have turned key off and back on while driving down the road. Best try and recover..

Now in the LBZ/LMM OS we have one table called cranking torque which our friends here made available for you to modify. Pretty straight forward, and is actually still used by the ECM when RPM goes below 500. Which saves our butts in these stand alone setups. But from my experience, the transfer between that and running torque tables is pretty messy.

So if you have issues cranking, bump up the numbers in that one which typically helps. Your purposely causing it overshoot the torque numbers once it brakes the 600r mark and moves over to our normal running tables.

More in a bit, gotta run.

Sent from my SAMSUNG-SM-G890A using Tapatalk

[jeeper]

Thanks again.

So I have verified my wiring. My wiring harness appears to match the harness document. All the switched and unswitched positive wires are connected to battery positive and the ground wires to the ECM and TCM are connected to battery negative. I don't believe I am missing any engine grounds either.

I have also verified the ECM does see engine turning over by using a Bluetooth obd adapter.

I'm wondering at this point if I should try spraying some WD40 into the intake while I'm cranking it over to see if it will at least attempt to fire?

[kidturbo]

I would check codes with V2 and see what it says. There will be a few to be expected such as no connection to BCM. If nothing jumps out, feel free to share what you see.

To diagnose it from here, I prefer to use the scan tool under EFIlive and check things such desired fuel pressure vs actual. If she don't see fuel pressure needed, won't fire. That will tell ya if maybe needs primed. If ya have lift pump, then typically not an issue. But can still take a few min of cranking to get all the air out. By looking at FP pid, can eliminate that really quickly..

Another one that will keep if from firing is APPS_1 or APPS_2 signal wire issues. If the throttle signal isn't pretty spot on, won't fire. I've ran into that one a before in swaps. Basically check throttle position pids and related while moving the pedal.

If it won't fire, it typically sets a hard code pretty quickly that will alert you to problem. If not wiring, then it's fuel..

Bests,

-K

[jeeper]

I hooked up my V2 today to see what I could see. I took some screen shots of the DTCs

I do want to state here that I realize I may have the wrong accelerator pedal but it does seem to be reading correctly. According to the information I found on line the 2006 LBZ is supposed to have GM part 15233970 but I am using a 25832864 pedal assembly.

It is the same pedal I have in my 2008 Chevy and I compared the values in that tune to the values the LBZ is expecting and they match exactly. Also when I monitor the pids both readings are identical for APP_D and TP_A. My assumption is it should work.

If I recall correctly I unplugged the accelerator pedal on my sons LBZ truck and his engine still started without it. I can certainly leave mine unplugged if that may be causing a no start.

I am curious if the transmission code would prevent the engine from starting? Or any of the engine codes that may stop the engine from starting?

What is the fuel rail pressure supposed to be? Mine was showing 2480 kPa.

[kidturbo]

Best to read the fuel pressure and MPA, or PSI.
You're shy about 5000 pounds of fuel pressure right now when it's cranking. They won't fire with 350psi.

Sent from my SAMSUNG-SM-G890A using Tapatalk

[jeeper]

So is this an indication I may need an injection pump?

[jeeper]

I'm in updating this thread while I'm chomping at the bit...I'm letting the starter cool down. I'm starting to see some white smoke coming from the exhaust. It's very tempting to keep going but I don't want to burn the starter up. I'm remembering back to my 6.2 GM diesel days now. I ran one out of fuel once.... You don't make THAT mistake too often after the first time.

I've run my 2002 Duramax out of fuel but it wasn't this bad to get restarted afterwards. I'm optimistic that seeing the smoke coming from the exhaust means I'm getting closer to a running engine.

[jeeper]

Another quick update. I figured since I may actually be getting close to a running engine I should probably change the oil before it fires up. The oil in the engine was black and unknown age. I had to lift the engine to get an oil pan under it for drainage. After the oil change I set the engine down and tried again to start it but got no smoke. So I pushed the prime pump button a few times and could hear air coming from the filter seal. It seems I may have an air leak in the fuel system. What I remember from my 6.2 diesel days is air in the fuel system causes a no run condition quickly. My next step is to see if I can track down a fuel delivery problem... I'll report back once I know more.

[kidturbo]

Sorry been under the weather a bit and not checking in.

The seal on the primer is a common issue that can cause NO fuel pressure that your experiencing. When data logging, try and get as many useful PIDs recoding as possible. And always record for playback later, then you can chart how that fuel pressure starts ramping up to get best view while cranking and such. That really helps me spot things out of place, especially if couple days later.

I think your most likely good on the electrical and tune for now, so might also suggest bringing up any other related questions on duramaxdiesels.com where you'll fine plenty of reliable info and help from many professionals. It's not always easy to work out some of the bugs on such swaps, but I'll bet at least a handful of member there have experience on any questions you have.

Bests

-K

Sent from my SAMSUNG-SM-G890A using Tapatalk

[jeeper]

I do want to state here that I realize I may have the wrong accelerator pedal but it does seem to be reading correctly. According to the information I found on line the 2006 LBZ is supposed to have GM part 15233970 but I am using a 25832864 pedal assembly.

It is the same pedal I have in my 2008 Chevy and I compared the values in that tune to the values the LBZ is expecting and they match exactly. Also when I monitor the pids both readings are identical for APP_D and TP_A. My assumption is it should work.


Another follow up. The engine did finally start. It took lots of persistence. I never cranked the starter over for more than 15-20 seconds at a time and only did that up to three times consecutively to be sure I didn't over heat the starter. I would put a battery charger on the battery and set the timer on it for about 40 minutes. Whenever I noticed the battery charger wasn't charging I would feel the starter motor to be sure it wasn't hot and would try again.

It seemed that it was getting closer to starting each attempt. After several days (on and off attempts) it finally started.

So I can confirm that the pedal assembly listed above does indeed work with the LBZ.

So for a re-cap, I tied all the pink wires to a toggle switch that simulates the ignition in the run position. I took all the orange wires (3 in total) and tied them to always on battery positive. I tied a separate momentary switch to the battery positive and the purple wire that goes to the starter relay. I cranked and cranked and cranked some more until I finally got all the air out of the fuel system and the engine fired off and ran. It accelerates smoothly using the wrong APP. Easy peasy...


I want to thank everyone who chimed in to help me with this.