Great Work, I can't wait to see the write up. I can't believe how fast you guys figured it out.

rubyred

 

1BADJK - Can you still toggle your ESP, and turn it completely off in low range?

The manual says you can toggle thru a couple ESP settings, but only in low range. Did grounding the low range sensor disable that function?

 

OK, I have had the opportunity to spend some "quality time" with the service information for the JK, and here is what I see...

The transfer case does not supply sensor ground to the control module. The control module provides sensor ground to the transfer case and many other components. This is on pin 28 of connector C1 on the Totally Integrated Power Module (TIPM). The transfer case switch then returns a MODE SENSOR SIGNAL back to the TIPM on pin 3 of connector C1 (Yellow/Light Green). This signal varies in resistance as follows:

Operating Mode Versus Resistance SENSOR POSITION OPERATING MODE SENSOR RESISTANCE (ohms)

Position/mode/ohms

1/2H/1124-1243

2/4H/650-719

3/NEUTRAL/389-431

4/4L/199-221

5/NOT USED/57-64

During normal vehicle operation, the Powertrain Control Module (PCM) monitors the transfer case position sensor return voltage to determine the operating mode of the transfer case. Refer to the Operating Mode Versus Resistance table for the correct resistance (1-6) for each position.

So it does appear by your testing that connecting this return signal to ground, which is the equivalent of 0 ohms, causes the TIPM to assume the transfer case is in 4 low. I quess the "perfect" modification would be to connect a SPDT switch to connect the signal return circuit to 220 ohm resistor to ground.

Or as discussed earlier in this thread, for those that want complete control over both lockers independently, you can just ground the appropriate relay to activate the lockers.

But the most important question is... Where are you going to mount the switch!

 

Now that we got down how to fool the PCM.. How do we get by the Speed sensor.. Which unlocks the lockers over 18 MPH... And locks the E-Disco back up.. ???????? Next project...

 

That might be a little harder...

That kind of information is passed between the various components on the CANbus.

 

Any chance you could post a few pictures of this, for those of us less electronically inclined? Thanks!

 

Take a look over here:

http://forum.*******.com/viewtopic.php?t=1720

Replace the ******* with the letters "j" "k" "b" "o" "a" "r" "d". Looks like we are still having to deal with these board administrators playing stupid games to keep you fro posting links to other boards...

 

so, i know this is a bit off topic but, 1badjk, could i get you to look something up for me in the fsm...just curious if I can find out the color of the acc wire coming out of the cigar lighter and which bundle it goes to. i think it just gets bundled with the audio wires and comes out the the left under the dash. would be perfect for my project....thanks
luigi

 

The wire to the cigar lighter is Dark Blue with Pink stripe (16 gauge). The wire to the power outlet is Red with Light Green stripe (18 gauge). The cigar lighter is switched and the power outlet is always on.

Can't tell you which bundle they are in since this is not shown in the FSM.

 

nice. ill test it out tomorrow and let youknow . i just didnt want to tear apart the dash if i didnt have to. thanks
luigi