4L60E Swap info needed... trouble with electrics

[townhome]

I just finished swapping a 1998 Vortec and 4L60E into my Jeep TJ. I used a painless harness that comes with the one large round plug that plugs into the passenger side of the trans. There are no other plugs for the driverside at the shifter location. Painless said I don't need them. My tranny guy said he "thinks" I do. Right now I've only test driven the Jeep at slow speed as I didn't want to damage the tranny. It starts fine in first but probably revs to 3000 before jumping into second. Any suggestions are appreciated.
Lee

[Lawrence]

Is the VSS plugged in? (it's on the tailshaft)

[townhome]

Yes it's plugged in. It's after market that came with the 4L60E to Jeep Transfer case kit but I connected it as per the painless instructions. It is an adjustable sensor that is a little bit tricky to adjust. I was told to thread it all the way down to the shaft that triggers the signal, then back it off 3/4 of a turn. It had fine threads and I think would have maybe 1/16" clearance. I used the Novak Swap stuff
http://www.novak-adapt.com/catalog/kit_4l61.htm
Is there any way to check to see if it is working properly?

[Lawrence]

Easiest way is to plug in a scanner and see what MPH it thinks you are doing, or it may even have VSS pulses on there. Have you had the PCM flashed with an adjustment for your gear/tyre combination? I have had the same symptoms with no VSS. Have you got an engine warning light? any codes?

[townhome]

We haven't had the PCM flashed with an adjustment for gear/tyre combination?
We will look at that next.
So the only plug I need for the 4L60E is the big round one on the passenger side?

[Lawrence]

Yeah, that and the VSS plug. It'll have thrown a code without a doubt. May be worth pulling the round plug off and making sure you dont have a pin pushed up or bent, and that it's going all the way into the socket.

[Steve Chryssos]

Hi Lee,
You will need to hold off on driving the vehicle until this installation is sorted out. As I understand it, you are using a GM PCM to control both engine and transmission. That is in conjunction with a Painless harness.

Your 4L60E must use both the main round plug and the two pin VSS connector that plugs into the tailshaft of the transmission. If your harness does not have a VSS connector, it's time to get with the manufacturer. You must also have a TPS to provide engine load data as throttle angle.
It is also mandatory that you reflash the ECM with proper final drive ratio and rear tire diameter. The 4L60E uses rear tire dia, final drive ratio and tailshaft speed to calculate driven wheel speed. If the calculated wheel speed is wrong, the trans will never shift at the right time.
Even more important is the TPS. IF the ECM has incorrect TPS input, the ECM will not provide proper line pressure.

Garbage in; Garbage out.

[townhome]

I'll do that Steve. Thanks so much for yours and others replys and suggestions. I've got lots to go on now.
Lee