bjherron

I am wiring up my 2009 5.3motor, 2007 4L60e trans, and 1988 NP241 to be installed in my 1975 K5 Blazer. I've come up with the following questions

1. Where do I wire the VSS signal to on the ECU? Doesn't seem to be a place for it since the np241 has a mech speedo output

2. Were do I wire the oss signal from the ECU?

3. Where do I wire the 2WD/4WD signal from the ECU?

Thanks for the help!
Brian

VEGASROBBI

1. Depends. What ECU, was it a 4 or 6spd 5.3? You need to run correct operating system(OS) in the ECU and TCU. The T42 is run on the 4l60's and the T43 for the 6l80(it's inside the transmission). I assume you have the T42 TCU with your 2007 4l60? Then the OS in the ECU must match the TCU for correct operation.
2. Again it depends on what you have, the 4x4 complicates things.
3. I fought this along with some other guys at efilive, there are some good threads there on this issue including my build and pics. Here's what I did on my 2007 5.3 LH6 4l70 4x4 from a Silverado into a Toyota.

Most OS's send the 4lo command to the BCM then through the bus to the ECM. Without this data the ECU will think it is always in 2wd, will not correct vehicle speed in 4lo, and it won't shift correctly in 4lo. I did not want to run a BCM so I used an Advanced Adapters transmission to TC adapter with a provision for a VSS. I used the 40 tooth reluctor from a F body 4l60 along with the VSS. I had to machine a split collar to fix the reluctor to the output shaft of the transmission since the splines had a larger diameter then then the mounting area.

Then I flashed a 2wd calibration into the E38. Now the E38 always thinks it's in 2wd; however, vehicle speed always reads correctly at the ECU and dash and it shifts fine in 2hi or 4lo.

Again there are many variables depending what you have, hope this helps.

bjherron

thanks for the post! Can you put up a link to your build thread?

Your plan sounds like where I am headed. AA makes a kit to put the VSS Between the 4l60e and transfer case. If I do this, does it matter whether I use a 2WD or 4WD calibration? Is there any benefit to using a 4WD calibration other than having it shift properly in 4-LOW?

Thanks again,
Brian

VEGASROBBI

Check out this thread:

http://forum.efilive.com/showthread....&highlight=AFM

If you stay with a 4wd tune with an invalid 4lo signal it puts the ECU in a sort of limp mode. The ECU disables AFM and it effects other tables, like timing.

Once I flashed in a 2wd tune it ran a whole lot better, no longer sluggish, and I got AFM to work.

bjherron

I think that's the answer I need, thanks!

I have an 09 LMG motor and an 07 4WD trans. Is it going to be a problem if I use the 07 4WD trans and 09 Engine ECU? Would it be easier to use the 09 trans ECU? Does it matter?

Thanks!
Brian

VEGASROBBI

If your LMG came with a 6l80 it will be a problem. I just finished a Jeep JK with a 2009 5.3 and 6l80.

The 6l80 has the TCM in the transmission, you would have to change out the harness and the ECU OS and add a T42 TCM to make the 4l60 work.

I really like the 6l80 and if your LMG came with one that is the way I would go. A bonus using the 6l80 is the VSS is already on the output shaft and sent to the ECU, no adapter to fuss with.

If you use a Corvette tune in the ECU and TCU you can get tap shift to work but you will lose AFM. In the trucks the tap shift runs through the BCM and you will be limited to drive and 2cd without a BCM. I find 2cd works well as a low gear cause the 6l80 has a pretty low 1st and 2cd.

Again go with what the 2009 LMG came with, easiest way.

bjherron

the 09 came with a 4l60e. I wish it had the 6l80e. So I guess I will use the 09ECU and TCU.