EROD LS3 6l80 Cruise control

[WAK]

Having a hard time getting the cruise to work. Its a Dakota Digital DBW 2000 series module. Ive installed many of these on Gen4's with 6l80's and E38 ECM's.
This EROD package uses a E67 ecm, but the main issue is getting the correct speed signal. The engine came from Pace perf, with a 6L80 harness. It has a bulkhead connector that plugs into the EROD engine harness and that bulkhead connector has a Speedometer output wire, thats what I'm trying to use for my speed signal input for the Dakota Digital module. Ive tried several different setting in the "Speedometer" calibration settings in the tune. Ive tried what works for my E38 setups and also tried the data from a complete ls3/6l80 connect and cruise package that uses the same engine harness and bulkhead connector as this Erod package.

Anyone been down this road or have any suggestions? Thanks!

[WAK]

I will also add that when i'm driving the vehicle the VCM Scanner shows 0 mph on the speedo. The transmission is working normal and the only trouble code is for a crank relearn.
Pomp EROD base, ls3 6l80, vss test4.hpt

[WAK]

https://paceperformance.com/i-238688...n-harness.html

This is the transmission harness that Pace uses to hook a 6L80 up to an Erod. I see on their site it says it requires "custom programmed with proprietary transmission software".
Zero Gravity perf sells this harness too and they also make the same claim.
Anyone have any experience with this, or know what they are actually changing?
I currently have an operating system and tune in the TCM that is from a LS3/6l80 Connect and cruise package (also from Pace) and the transmission works properly, but the ECM is not seeing the vehicle speed signal.

[Alvin]

I'm in the same boat! Only with a GMPP LS3 and a junkyard 6l80e!!!

Does the speedo output on the bulk head run gauges? Could you tell me where do the wires for the VSS go from the bulkhead connector? I assume somewhere on the 6l80e connector.

I'm having the same issue. I've been talking with Hptuners about it but I'm not sure we will find a solution.

My take on it is this..

A while back we did a V8 colorado swap with a manual transmission. V8 Colorados never came with manuals so we wired it like a stock V8 colorado minus TCM and VSS wires ran directly to the ECM just like it would be in a manual application. Why is this relevant? Well I couldn't get the speedo to work regardless of how I set the speedo section. I tried ever combination. Never worked. At the time the segment swap tool wasn't working to allow swapping speedo segments from 4 or 5 cylinder tunes with the same OSID. I got Hptuners to go back and allow this or fix it and it worked.

So if the original application was a manual (I feel certain this is the case with all GMPP ECM's) than the ECM will always assume it's the one to provide and broadcast VSS over CAN. If it's an automatic OS originally no matter what you set the speedo tab for it will assume a TCM will be there to broadcast VSS to everything else. There must be a setting somewhere in the ECM that allows it to either MASTER and send or SLAVE receive VSS stuff.

When I segment swapped a I5 manual speedo segment into a V8 automatic file the speedo worked perfectly even though everything in the speedo tab was already exactly the same as the manual file.

I think if you could segment swap a speedo segment from a automatic file into the GMPP controller your and my speedo will work. The problem is I think the GMPP OS isn't from anything stock and I don't know of any compatable automatic OS's you can swap the speedo segment from.


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Here is something interesting that might help you. I went back and reflashed a E67 as a 2008 TBSS and my 6l80e and ECM now both share VSS. Speed does log now. The new problem is the pedal isn't compatible. It throws P2135 immediately IF you were to do this and change to a TBSS pedal (pedal harness has A&C swapped too BTW) than you would have a 3 wire hookup to get the factory ECM to run cruise. TBSS is the only Gen 4 application I know of that has cruise built in with no BCM required.

It doesn't fix my problem because fitting a different pedal is going to be an issue. (Car is done and pretty tight)

[WAK]

Are you using this pace perf PCSA-TCM4410 harness? https://paceperformance.com/images/F150148893.png
I did make some gains on this yesterday. The VSS connector from the GMPP harness will plug into the short lead (on the pace harness) coming off the main connector on the 6L80, its labeled OSS signal.
Once I connected those, and changed my vss settings to RepTOS, that did make the "speedometer" output from the bulkhead connector live.
I now have a working cruise control, But my vehicle speed still does not read on the VCM scanner. I'm wondering if it has something to do with the fact the the Erod ECM doesnt have a real VIN, and the scaner thinks its a 1990 something. I'm going to try a couple different scan tools and see if any of them display mph.
As far as the GMPP e67 ecm, I can only make VERY minor calibrations to that.... This is a California vehicle and has to pass certification, thats why we are using the Erod package on this build.

[Alvin]

Could you tell me where those OSS pins go? I'm not talking about where you plug it in but the source of those wires. I'm thinking it should be on the 6l80e connector somewhere. There is a chance I might be able to get this to work by letting the ECM think it is still an manual but a auto is in the background doing its thing.

[WAK]

Could you tell me where those OSS pins go? I'm not talking about where you plug it in but the source of those wires. I'm thinking it should be on the 6l80e connector somewhere. There is a chance I might be able to get this to work by letting the ECM think it is still an manual but a auto is in the background doing its thing.

Just look at the pinout for the year 6L80 you have. the OSS is on the main round connector, its something like pin 14-15? I dont have the truck here right now.

[Alvin]

Just look at the pinout for the year 6L80 you have. the OSS is on the main round connector, its something like pin 14-15? I dont have the truck here right now.

That's why i'm asking. I've never seen a stock 6lXXe with a VSS output. It's always been done via CAN BUS.

[Alvin]

I stand corrected. Never realized trucks had a hard wire OSS from 6l80e. I've got some ideas I'll report back. I did find a OS that would communicate w/ the 6l80e and get VSS via CAN but it requires some back end changes that most can't do on their own.

[Alvin]

I got mine all working, tap shift, VSS reporting in the scanner and outputted from GMPP ECM, pedal, etc. Everything is good to go. If you still need help LMK

[WAK]

I'm still not getting VSS reporting in the scanner.

[Alvin]

Do you have anything plugged into the VSS connector on the GMPP Engine harness? The one originally intended for manuals? or do you not have that.

You don't have the setup with a box hanging off the side of the 6l80e do you?

[WAK]

The VSS connector on the GMPP harness is plugged into the OSS signal coming from the 6l80 harness. I'm also using the "speedometer out" signal from the GMPP ecm harness, that is the signal im using for my dakota digital cruise control. Once I got the vss data set correctly for that type of signal my Cruise control works. I have a mechanical driven speedometer from a Transfer case. The Only thing I'm missing is VSS reporting in the scanner.

[WAK]

ttt

[Alvin]

That should work. You can try overwriting the TCM with another file but it sounds like you might have some other issue.