LS3/6L80e Engine Swap into my 73

[DirtDonk]

F3 Fuse pulled:
1) ignition on, amber lights are off and so are the dash lights.

Sweet. A success!

2) Ignition switch off, turn headlamps to first position and the driving lights come on.

Another success!

The dash doesn't.

Bummer!
But maybe not too big of one. Perhaps it's only because you now have to complete the circuit you just disconnected.
For that you will need to leave the fuse out, cut the wires off of the new panel, then connect them together via an independent, in-line fuse.
You can check this, I suppose, by re-installing the existing fuse, leaving the key OFF, and pulling the headlight switch out one notch.

I didn't change the wiring of the ignition switch nor the headlamp switch.

This is a good thing at this point. Should make it easier to track down and fix any gremlins

And the hazzards don't work, but the blinkers do.

Good for having the blinkers. The hazard wiring has always given me a headache. Whether dash mounted, or column mounted.
So, do the hazards work under any conditions? Key ON or OFF? Light switch on, or off? Brake pedal depressed?
Do the brake lights work?

Paul

 

[WPS 73 Bronco]

Brakes lights work.

When I get home, I'll retest the scenarios as my memory is fading.

Back to the Dash Lights.... I know I wired them wrong by eliminating the inline 2 amp fuse and wiring one of the BL/R wires to the ignition fuse box and then I must have capped the other wire off. My solution will be to pull the BL/R connection from the fuse box, and tap it into a headlamp switched wire with an inline fuse. There's no way I'm going to pull the dash out to find the other BL/R wire I capped off.

 

[WPS 73 Bronco]

Just tested everything again. No difference in what I’ve said before.

So, if I run this way for a while will I damage anything?

 

[DirtDonk]

Shouldn't just from the things you've described. Doesn't hurt anything for the lights to come on and go off. Doesn't hurt anything for a light to stay off.
Only if you leave something on will it drain the battery. Can't think of anything in what you've described that would harm one thing because another was lit up.

Now, if anything is working it's way to the top, but still unseen and undiscovered, well, we can't predict what that will be or what else it might effect.
But other than getting a fix-it ticket for being out of compliance on one thing or another, you should be good I would think.

Paul

 

[WPS 73 Bronco]

Yesterday was a big day. Here’s what I got accomplished:
1) finished rear diff 3rd member & axle swap.
2) completed the rear drum brake rebuild and bled brakes.
3) installed hood and verified engine would maintain correct temperature.
4) bled the air out of the hydro boost system.

You know what happens next……. The first test drive.

The only issue I have is the 6l80 isn’t shifting through the gears, once I’ve in drive. It seems like it’s in limp mode, but I’m not sure.

Here’s the wiring diagram from the Holley Terminator X

I’m guessing the issue is in the park/neutral or the brake switch wiring. Seems like Holley told me to ground their engine harness park/neutral safety wire, so i did the same for the transmission wire noted above. Regarding the brake wiring, I wired it to the red/black wire on the brake switch per below. I’m guessing the park neutral is the issue. Any thoughts?

 

[WPS 73 Bronco]

Ok so I’ve verified it’s not limp mode. It just doesn’t want to change gears once it’s in drive. I have reverse and neutral. When it’s in drive I can’t tell if it’s in 1st or another gear. Regardless, it wont shift.

 

[DirtDonk]

Are you rolling on the ground during this test? Or the wheels up in the air?

 

[DirtDonk]

And by “grounding“ their wires, do you mean, you literally grounded them yourself? That’s so that it will start and drive and you have other wires, such as from the computer, controlling neutral safety issues? Seems to me their instructions are simply reading it like a normal neutral safety switch. Where it’s grounded by the switch. Not grounded all the time.
Then again, I could be reading it wrong and I just glossed through it. But that definitely seems like something to look at.

 

[WPS 73 Bronco]

Paul, this is wheels down, driving down the road. It stays in 1st gear and doesn’t shift.

I’ve read the error code and it says it’s lost connection to the ECU.

Regarding neutral safety, Holley told me I could ground the engine neutral wire and then the engine would start. I did that weeks ago when I first got it to crank.

I had two remaining wires to complete for the transmission, it has a brake and a neutral wire.

I connected the brake wire to the red/black wire on the brake switch and the grounded the neutral wire to the chassis.

I’ve disabled the ground wire and nothing changed.

 

[Yeller]

It’s possible the brake switch is normally closed, I’m not familiar enough with Holley to know. The OEM system is normally closed and open when the brake is activated.

 

[WPS 73 Bronco]

Which wire on the brake switch is hot? I’m assuming it’s the red. That’s what I have it tied to.

Holley says + 12v, usually the brake switch.

 

[Yeller]

Is that 12+ constant or when the brake is applied? Asking because the OEM computer is 12+ all the time and open when the brake is applied. GM uses a DPDT switch one side operates the brakes and one operates the computer. One set of contacts is normally open and the other is normally closed. Broncos use a single pole switch that is only closed when the pedal is depressed. I’d try connecting the brake wire to 12v+ constant and see what that does, worst thing it can do is stall the engine when stopping due to the converter locking, if it does you’ll know the cause and the solution is to install a GM 4 pin brake switch.

 

[WPS 73 Bronco]

So my saga continues with the Holley 6l80 controller. Between Holley and myself, we’ve concluded that all wiring is done correctly. We’ve checked Pin Voltage at the connector of the transmission and all pins check out correctly. Holley is suggesting, but not saying definitively, that my TCM is the problem.

In the mean time, I’ve searched locally in Houston with performance shops and not one of them even knew that Holley had introduced their 6l80 controller. I’ve talked with at least 6 “experts” and they are stumped. I’m going to try a local transmission shop and see if they can diagnose it via the OBDII port, but I’m skeptical.

The issue is communications between the tranny and the Holley ECM…..nothing.

 

[Oldtimer]

 

[WPS 73 Bronco]

I wish that was the answer.

 

[WPS 73 Bronco]

It looks like we've found the issue. Holley advertises that their controller will work with any 2007+ MY 6L80/90 transmission. It's in the product description, plain and simple. On the last page of their installation manual for how to tune with their transmission tuning handheld, they have a matrix noted that the "Matrix below lists the OS that are installed in the TCM depending on (tuning) selections.

Well guess what, my TCM is not on the list. My 6L80 transmission is from a 2014-17 vintage build and has a TCM that runs off a different Operating System (ECU) than the ones that Holley designed around. Holley is saying they only support the ones listed on this page and they aren't responsible. So this means that the transmission TCM can't talk to the Holley ECU because they have different operating systems. You can talk to the transmission via the OBDII port, but that's as far as you can go. GM has the same issue with their own ECU's & TCM's, they just have to have compatible OS's. Holley should have known this and put that disclaimer in the description instead of saying "ANY 6l80".

My challenge now is to try and re-program (Flash) the TCM to one that is supported. I've gone to my local Chevy dealership, and they declined because in order to Flash it you have to have a VIN that matches the updated TCM. Their company policy is that they can't use false data to trick their tunning software. After numerous calls I've found a tuner that will try and get do it. The risk is that an error code pops up and "Bricks" the tranny. If that happens, I will have to purchase a new TCM that is pre-programed.

Fingers crossed for success tomorrow when we do the re-programming.

 

[WPS 73 Bronco]

Lots of things have happened in the last 2 days. Got the 6l80 TCM flashed, followed by the Holley ECU going crazy. After I wiped the system and reinstalled the firmware and a tune I had from last week, the Bronco ran well and the transmission is shifting gears but not at the shirt points I want.

Then the fun started. I took it out for a lightly spirited drive, punched it, and next thing I knew the engine dumped all the oil on the hwy with tons of brown smoke behind me. I was about 3 miles from home so I drove home wondering how bad the engine was. Engine temps never climbed above 220 so I was hopeful. By the time i was pulling into my driveway I could hear the motor making ticking sounds.

I climbed under the truck to find that the oil filter had spun loose, but not off. I put on a new filter, added oil back to the engine and started it up hoping I didn‘t just ruin the motor. I turned the motor over slowly three times, started it once for 2 seconds, then decided to see what would happen so I started it up. First 5 seconds it sounded weird but then it settled down and ran like before. No smoke, no cylinders ticking or missing.

Damn I’m lucky. Check out my pics. I really like the radiator support that I had Dan Car make me.

 

[WPS 73 Bronco]

 

[WPS 73 Bronco]

And a couple videos

 

[WPS 73 Bronco]

UPDATE:

Engine is running fine with no signs of concern from losing all the oil.

Transmission communications are resolved, gears are shifting, etc. I'm still working with Holley on optimizing the tune. It's pretty clear that their 6L80 tune management isn't as developed as their 4L60 technology is. The 4 speed has a lot more tuning options compared to the 6 speed. We are trying to optimize shift points, torque levels, etc and it's a bunch of trial and error. I'm guessing that the TSP Stage 2 cam and my 3000 stall TC isn't helping

Other than that, the overall performance is solid with plenty of power. I did replace the straight through Magnaflow muffler with a true baffled muffler. Before it sounded like a stock car starting up in my garage. Now my wife is okay with it and will actually go for a spin in it without commenting on how loud it is. We also leaned out the tune which has helped the exhaust smell dramatically.

Overall, I'm thrilled with the work and the results. I've still got a few things to button up:
1) complete the E-Stop e-brake installation.
2) install the Axle Wrap
3) install the 4.10 gears in the front diff and purchase a new drive shaft

Once that's complete, the original project plan is completed. After that I need to go to phase 2 which first on the list is front steering upgrades. Likely going to TRO.