kidturbo

Seems the LS marine swaps are gaining momentum.

In the past couple months two members from here, and third company out of Asia all hit me up about CANbus gateways to connect LS3's, 7's, and 9's to N2k networks. The contact out of Asia has "hands down" the coolest LS powered boats to date. They fly, literally... Seems the upgrade costs and options like drive by wire and flex fuel offered with the LS engine package is catching on.

Having previously wrapped up protocol conversions and testing with Holley EFI, AEM, J1939, 06 Cummins, and the high speed GMLAN found in trucks [Duramax], I figured the 06-12 LS models would be a breeze. Nope, not even close. Seems GM used a completely different CANbus protocol in all the Corvettes as I soon discovered. After bricking my buddies spare ECM, I headed to the bone yard and picked up a couple more E38 ECM's, then loaded up the most popular Corvette OS versions.

First thing to know about the GM E38 ECM, only certain Operating Systems [OS] will run on specific hardware release models. They all look identical. But loading an 09 LS3 OS into a 2011 E38 ECM out of a truck, equals a nice new paperweight.. Luckily these are by far one of the cheapest ECM's to buy used. $35 each, any years, out the door of a major chain boneyard. So before getting to far into wiring up your LS engine, pick the best GM OS # to fit your build, then check the cross reference sheet here:
You can't go by the numbers on the outside of case either. Must know the production year the ECM came from then verify what OS is currently installed to avoid problems.

Next thing ya gotta verify is the engine harness pinout matches the factory OS you just picked. Once again, GM swapped a half dozen pins or more around based on what chassis that particular OS supported. So running a LS9 Vette ECM with an 6.0L truck harness is gonna give ya fits. But luckily these connector pins swap out easily. Or you can just purchase a nice stand alone harness ready to go for your specific OS. But for my testing it was all just strung together on the desk to capture data.

While verifying all these sensor inputs I noticed that Engine Oil Temp [EOT] pin on J2 connector wasn't supplying any EOT PID value, but rather TFT or trans temp. In the GM manuals it shows that pin 23 as EOT or TFT based on what transmission was attached. Ok, the OS I have matches the wiring diagram, so what gives. A Google search revealed that while most LS models came with an EOT sensor in the oil pan, basically none of them used it. GM opted to "Estimate" the EOT values used for tune tables and sent to the DIC or dash. And they look to have estimated high, using RPM, ECT, IAT, oil pressure and load to come up with an Oil Temp value. Guess running that extra wire 3 feet wasn't cost effective. But in a marine setup with good oil cooler, that estimated EOT will be way way off from true temp.

When you edit a factory E38 tune file with EFIlive or HPtuner software you'll see a "Misc" table that says EOT Input. With options like Calculated, Sensor, Sensor and CAN options. Useless.. Nothing seemed to change no matter what option I picked. So I hit up my friends at EFIlive for answers. Once again, that pinout vs OS issue. But they quickly found the problem and sent me some data to create a custom CAX file to reassign Pin 23 as EOT in the LS3 OS. That problem is solved.. Posted how too details and cax file links over at

So now we have all the main LS gauges translating into N2k and J1939 output streams. Still working on a couple extra pin mods to bring water pressure and fuel pressure in on unused 5v sensors like AC pressure. Also working on a wideband O2 option for those who want it. For now it looks like best option might be swapping those in place of stock O2 sensors and rescaling. Still testing for best option. But with an ability to safely run flex fuel percentages, I think the factor LS hardware is gonna make a great choice for upgrading to EFI.

Here is a short of the LS3 ECM running on bench and piping engine data through our CAN gateway to a couple NMEA displays. Along with clip form one of our Beta testers. :-)

Now it;s onto the E67 ECM, which probably yields more potential for turner friendly swaps due to all the extra inputs and boost control...

-K

hallj

Thanks for the legwork. If just for data display, a obdII Bluetooth adapter and a tablet? The only inconvenience is starting up the tablet every time you start the vehicle.

jeff

sutphen 30

great work here,thank you for the effort.

do you need to get the vin # from the vehicle the ecu comes from?and are you saying to only look at 2009 ecu from a vette or will any of the E38's work?

kidturbo

If all you're looking for is some extra engine data or to check codes, then Torque is a great little app. Just having it installed on a phone, and a BT OBD-II adapter handy, will cover most diagnostic issues that you ever encounter. Best $30 scan tool setup you could own. However ya ain't gonna like viewing consumer grade tablets in direct sunlight. Tried that on a boat a few times. But for a nice clean dash install, about any of the NMEA2000 capable displays will do just fine.

Personally I like that little Simrad used in the video the best. Full of cool features like pop up windows on trim changes [if properly equipped], and you can set all the important engine alarm values. Built in depth sounder screen also. Think I paid like $250 for it used off eBay. Doesn't require much real estate, so you could run one with analog gauges for temps, pressures, and Tach. It's aso possible to run a normal pulse input style tach on the E38, by assigning the output pin in the tune.

All the E38 hardware looks identical. However only certain OS [operating systems] will run on certain model year ECU. So if you want to run a 2009 LS9 OS, you can use an ECU from about any other 2009 vehicle. Just need to flash the LS9 OS into it using a Tech2 or tuner tool. What ya can't do is take a 2012 ECU from a truck, and load a 2009 OS file onto it. Learned that one the hard way... Luckily EFIlive made a reference sheet, "link above" which tells what will interchange. So ya power up the ECU somehow, read the existing OS # from it, then check the cross reference page before proceeding. Then for wiring harness pinout, you follow the schematics that match the year vehicle OS your using.

I plan to get into this wiring a bit more detail soon as I grab a couple E67 PCM's to play with. A good example of pinout differences is how the MEFI 5 and GM E67 ECU are identical hardware. But if you check the pinouts, you'll quickly notice multiple pins are assigned different. GM seems to have don that a good bit between years, models, and engine platforms. E38 for example also used on most V6 engines during same period.

kidturbo

Working on a little side project for some 1000+hp LS GDI "Gasoline Direct Injection" tuners this week.
Direct Gasoline Injection is Here, and it is Time to Get Familiar

One of them sent over most of electronics out of a 2016 Camaro to mess with. To overcome HP limitations of these new injectors, trick looks to be running dual ECM's, and stacking a set of old style LS injectors in the runners down wind of the SC or turbos. Then bring em online only when required.


While the E92 ECU still looks friendly to stand alone applications, DBW drive by wire is gonna become pretty much a mandatory upgrade. GM has updated the throttle body TPS sensors to this new "J2716 SENT" Serial Data protocol that no longer uses analog 0-5v slopes curves to supply position to ECM. While I think it's likely possible to hack up a TB and remove the controller motor and run cable, the rest of the internal electronics aren't as easy to fudge. But with LS calibrated APPS based sticks available from Livorsi, cables are gonna soon become a thing of the past on EFI.

All the non-vette engine CANbus data look the same going clear back to 06. So another plus for ease of wiring. But I'm still torn on fobs and push button start in a performance boat... Anyone salt water tested their new GM key fob yet?? Just wondering... Maybe a security pin keypad like in Franks BMW / Transporter 2 would be a better fit.

hallj

Keep up the good work. Having port injectors up stream can help out with cleaning out the carbon build up with typical GDI applications.

You'll be able to warm up your boat while you're
downing your last beverage at the bar.

Do you know of a good display to use that will plug into the OBD II port for data display?

Jeff

kidturbo

Depends on what your looking to do. For marine use, any modern N2k plotters will show engine data when connected using one of the CANbus gateway I designed for some Holley EFI guys on here few years ago. It's not based on OBDII, but actually takes the place of the body control module "BCM" in a vehicle. It translates all your high speed engine data into a protocol the N2k plotters can understand. So ya get all the same gauges in a car, plus some extras like engine load, torque, boost, engine intake temps.

If your just looking for "non-marine" standard displays, I'd suggest AIM units since they are monochrome type and will show up good in direct sunlight. They work off OBDII, but only display a single engines data. Meaning you need two displays on a twin engine boat. As where a Garmin or Simrad type marine display will show both engines on one unit, or multiple displays at at same time.

GrannySShifting

Thhe factory does this on the newest supercharged Vette. They couldnt fuel it with just the DI, so they have a piggyback computer and port injectors. Pretty clunky to me. There are injector solutions feeding 1400hp sofar, but on gasolines. Pump are silly pricey as well.

I will stay with port fuel injection for any real power builds, too flexible, too easy, too simple

Im in the middle of a twin LSA blown Donzi swap, using cable drive, hybrid Corvette/truck OS and ECUs, flex fuel capability etc

kidturbo

KISS is often the best strategy with stand alone swaps.

Think you'll like that flex fuel capability. A member I helped get the gauges ported over and fix that oil temp issue above, dropped a pair of DBW LS9's in a Cig making over 1000hp. Nice when you can fill up with E85 on the trailer, but not have to worry about finding exact same fuel out on the water.

underpsi68

I run a flex fuel sensor on my turboed street car. Works awesome. Aftermarket ECU changes boost, timing and fueling depending on alcohol content. It also has a built in fuel temp sensor. In all my testing the fuel temp changes the a/f. The higher the fuel temp, the more fuel that has to be added.