Vintage Gas Pusher Motorhome LBZ Swap

[LCAC_Man]

I need some help. I'm pushing towards a test fire of the engine this weekend but have hit a snag.
With this swap (07 LBZ/Allison) I'm using the factory dash cluster and BCM, I powered up the system last week and with HPTuners was able to pull my tune off the ECM/TCM, I disabled the VATS and installed that tune(only change I did). So I know the high speed data is working properly.
After hooking up my dash cluster I noticed it wasn't responding to key on power other than to give me a check engine and pass lock light. I had initially thought I had a bad cluster but since most everything in the dash cluster works off Class 2 serial data I decided to see if that was the problem. I tested for voltage at Pin 2 of the DLC and it's dead(should be approx 5vdc from what I've read). I also tested for it right at the splice pack (SP205) and found it to be dead as well.
Do I have to trick the BCM to get it to generate class 2 data even with VATS disabled?
I'm not using the factory key/ignition do I need to convince the BCM that I am even though VATS is disabled?
Also curious if the relearn values can be set to zero?
Here's a link to a picture album of the project:
http://www.fmcowners.com/mbbs22/phot...sp?albumid=127

[LCAC_Man]

Well it appears I may have been running a fire drill.
I plugged in my obdII scanner and I'm not reading any loss of communication codes, what I had thought was zero volts on the class 2 data line was just very low voltage (around .5vdc). I then went and checked my 06 Chev Colorado and my rockcrawler with an 06 LS2 in it and both of those also were less than 1 volt.
So...it may be just what it appears...a bad dash cluster...which I suppose is about the easiest to fix as I found a local guy who does full rebuilds for $170, another give away should have been that when I shut the key off and the cluster only had battery power the headlight "bright" indicator comes on dimly.
I have a scan gauge II and plugged it in and I get water and inlet air temp no problem so I think I may still be able to fire this thing up this weekend. I still haven't wired any of the lighting/dimmer circuits to the cluster but I can't imagine that would influence it's power up..

[McFoo]

What was all done to the wiring harness?

[LCAC_Man]

Very little was done to the harness, I'm using the factory underhood fuse box and left the interface connections. I'm using the BCM.
I found that I had two problems. First was the dash cluster needing new stepper motors, second was that I was missing an "accessory/run" voltage to connector C4 of the BCM.
All is working fine now and I was able to start the engine yesterday on the first attempt.

[LCAC_Man]

Any insight to the difference between Final Drive Ratio "Ratio" and "Trans"? My motorhome rear axle ratio is 4.62, should the "Trans" ratio be different?

[RandomEnthusiast]

Trans ratio should be fine as long as it doesn't have a different geared planetary. Final ratio is I believe axle? I can't remember.

[LCAC_Man]

I went into the help section and it says they both are the rear axle gear ratio. It may be an option if you had a two speed rear axle or something like that. Just strange that the stock tune has 3.73 listed in one field and 4.10 in the other...
I read quite a few reports of the same.
I'm just going to change both boxes to 4.62 (my axle gear ratio).

[Swandog66]

i have to say that is an awesome project.Impressive attention to detail and quality craftsmanship.

[LCAC_Man]

Down to the last code. I'm still kicking a P0101 MAF out of range. It is an actual as I installed a completely custom intake system that seems to be flowing about 20% more air. My idle MAF reading is at 60g/sec vs the mid to high 40's of a stock LBZ intake.
Can I modify the MAF table (airflow to volts) to accommodate for this?

[LCAC_Man]

Solution was to multiply all the cell values in the MAF table by .66 it brought my idle MAF reading down to 40g/sec. No more P0101.