3.7L V6 QT1 to QT2 Conversion.

[cmdr jim]

I'm getting ready to install my NV245 transfercase into my XK. I have bench tested my program and controller for the last few weeks with excellent results. Very consistent results shifting the transfercase between all positions. Confidence is high that it will work. Only concern I have is throwing a Gear Ratio error code in Low or Low Loc position, which I will find out shortly, and I believe I have a fix for that if it occurs.
I am using the stock "T-Handle" transfercase switch, which will look stock. I Also have a power on "Key" to power on the controller and modules. My intent is for this controller to be completely off, with no power to it when driving "On Road". Off Road, you would power up and it would provide full manual control of the transfercase. Why not a simple linkage to shift, because this transfercase uses clutch packs to lock in high and low and requires the torque of the motor to apply pressure and hold it there with a brake.
Below is the way I see it operating, rough draft:


Transfercase Mode Selection.

Off Road Operation Only.

The procedure to shift (Select Mode Position) is as follows:

1. First turn on the power to the controller with the Keyed Power Switch by rotating it clockwise.

2. Press down on the vehicle’s brake pedal.

3. Shift the transmission into Neutral or Park.

4. Using a pen or other pointed tool, depress the Mode “Pen” Switch fully down and release. (This places the controller in the select mode) The “N” Indicator Light will light up solid to confirm the controller is in the select mode.

5. Next raise the Mode Select T-Handle up fully and down the number of times required for the Mode you desire to use.

High Loc = 1 Count
High = 2 Counts
Neutral = 3 Counts
Low = 4 Counts
Low Loc = 5 Counts




6. After you have made your selection, depress the Mode “Pen” Switch fully down and release. This locks in your Mode Position Selection and powers the transfercase motor, which shifts the transfercase to your selected position.

7. Once the transfercase has been shifted, the “N” Indicator Light will flash the transfercase Mode Position.
“N” Indicator Light will flashes the following codes.

High Loc = Light on, then off for 2 seconds
High = Light on, Light off for a count of 2, then off for 2 seconds
Neutral = Light on, Light off for a count of 3, then off for 2 seconds
Low = Light on, Light off for a count of 4, then off for 2 seconds
Low Loc = Light on, Light off for a count of 5, then off for 2 seconds



If you see a continuous rapidly flashing light, there is an error in the shifting of the transfercase. Please refer to the Error Code Section.

8. After the transfercase has completed the shift to your Mode Selection and you have confirmed the “N” Indicator Light has flashed the correct code, you may turn off the power to the controller with the Keyed Power Switch.

9. Shift your transmission back out of Neutral or Park .


Transfercase T-Switch Special Features

Off Road operation only.

With this controller for off road only, there is an option of leaving the power on while off road.
If you choose to leave the power on during off road use there are two additional features available.

These options are:

High to High Loc toggle shifting (on the fly)
Low to Low Loc toggle shifting (on the fly)



On these two options, it is not required to apply the brakes, place the transmission in Neutral or Park, nor depress the Mode “Pen” Switch to shift Mode Positions. This can be done, because the transfercase does not need to go across the neutral position of the transfercase to get to the other mode position.

1. The procedure is to raise the Mode Select T-Handle up fully and hold it up for 2 seconds, than lower it back down. If you were in High, the transfercase will be shifted to High Loc and vice versa. If you were in in Low Loc, the transfercase will be shifted to Low and vice versa.

2. After using the Mode Select T-Handle, always verify transfercase position by confirming the “N” Light is flashing correctly for the Mode Position selected.

This feature is very effective for negotiating tight trails. Example: Using Low to allow for easier turning and less wear on the drivetrain in easier and/or tighter turning areas, then when encountering a section requiring maximum traction, the Mode Select T-Handle can be used to toggle the transfercase into Low Loc. Once the section is completed, simply toggle the transfercase back to Low. Same example but only using High and High Loc as required.

Error Code Section

If the transfercase shift motor is unable to complete the selected Mode Position, the “N” Indicator Light will rapidly continuously. The main reason for this error to appear is when crossing over neutral the transfercase gears are not aligned properly to allow for complete engagement. What this means is the transfercase is stuck between positions.

The procedure to correct this error is:
1. Turn the power off to the controller with the Keyed Power Switch. Wait 5 seconds and turn the power back on, this will reset the controller error code.

2. Next use the Mode Select procedure to shift the transfercase back to the original Mode position.

3. Shift the vehicle into drive or reverse and move the vehicle slightly to re-phase the transfercase gears.

4. Then follow the Mode Select procedure to shift to the Mode Position you were selecting.

If this does not correct the problem after a few tries, then the other possible causes for this error are, no power to the transfercase motor brake or motor and/or a bad transfercase motor. See Troubleshooting electrical parts.



Why the power key, brake, neutral and Mode “Pen” Switch? It's to insure there is no unintended use or shift of the transfercase, unless you are completely aware of what you intend to do. Safety First.

[Ross]

That is awesome!!! I love the fact that because of people like you, we can all upgrade out jeeps to their full potential. Thanks, +rep fo' sho

[07JeepXK]

Cant wait for you to get this installed! I wish I had the knowledge you have when it comes to stuff like this.

[cmdr jim]

I mounted the controller under the dash just left of the steering column last night. I'll post some pics later this weekend And I'm making a panel that will go under the passenger side rear seat for the relays, sensor module and motor module. My idea is to keep all the electrical components inside the jeep. I should be able to start working on the wiring this next week, with the goal of installing the transfercase and being fully functional on the weekend of the 20th. Hoping for no Gear Ratio errors in Low or Low Loc. Reading the service manual, it could go either way. Best bet is I will need to shut off traction control, which makes the ARB rear locker and "manual" front ELSD more important.

[cmdr jim]

Here is a picture of the controller mounted under the dash, just left of the steering column. No wiring to it yet.

[cmdr jim]

To mount the Transfercase Select Switch, a couple holes need to be drilled on the bottom of the Shifter storage area. And a hole provide for the Switch Plug to plug into the rear of the Switch.
I think I can make a template for these holes.

[cmdr jim]

Here is the Transfercase Selector Switch mounted and plugged into the stock wiring harness. My XK had this wiring in place. But it needs to be modified to work with my controller.

[cmdr jim]

Here is the modified wiring, Pins 1, 2 & 3 cut and wired to run to my controller. Please note I have soldered and heat-shrink-ed all connections and sealed of cut ends of wiring harness that will not be used. I have run these wires along the stock wiring harness using tie-wraps. All changes under the console are complete.
Next will be making up the panel to mount the two modules and relays that will power and control the Transfercase Motor, that will be going in under the passenger side rear seat.
After that running the wires between the two areas, adding the key switch and testing the Transfercase before actually installing it. One step at a time.

[07JeepXK]

Its looking good. Cant wait to see more pics!

[Sal-XK]

Heck of a mod man!

[cmdr jim]

I hope to have the wring completed this weekend. I plan on putting the transfer-case in the back of the XK and just wiring it in before actually swapping in it. I can then check out my wiring and programming before the actual install. Installation is planned the weekend of the 19th if all goes well.
Keep in mind, I'm working on this slowly, a couple hours here a couple there.

[cmdr jim]

Another step closer. Under the rear seats of the Commander there are to small areas covered by a carpeted lid. On the driver side is were the FDCM and Parking Control Module would go. On the passenger side, mine is empty and it provides a perfect place to mount the relays and voltage regulators. Next step is to ground the panel, provide power and final connecting of the wires to the controller under the dash.

[1USMC]

cmdr jim ...

Wow.. the transmission work you are doing is way over my head, but if it is anything like your wiring job it should turn turn out great. I tinker as an amateur with my own wiring. I can appreciate all the time you put in and the professional wiring work you do. Keep up the good work..

[cmdr jim]

If you all remember way back, I was lulled into the idea a Jeep dealer or Jeep itself could upgrade my QT1 to QT2. I was collecting all the parts to do so. even to the point of swapping out the mid underframe wiring harness.
Of course the Jeep Dealer or Jeep didn't happen. And that why I'm here.
Moving forward. with that new wiring harness, there are connections under my rear seat for the FDCM and under the Jeep the connection for the Transfercase Motor. Yes you guessed it, I spliced into the wiring harness under my rear seat. This gives me all connections inside the jeep.
However, if someone else were to do this, there is a large grommet under that same area under the rear seat, wires can be brought up through that grommet and sealed. You could find a junk yard WK or XK with QT2 or QD2 and get the Transfercase motor connection from one of them. Or worst case buy a repair splice-in connector from Jeep. Part Number #68040504AA

[cmdr jim]

I have the transfercase in my Jeep!

Well, technically it's in the Jeep, in the back cargo area :p
But it's all hooked up electrically and functioning just like it did when I was bench testing.
So that means the electronics wired into the Jeep work!

[07JeepXK]

Nice... get that thing bolted in under the XK now!

[cmdr jim]

The has been a long time in the making with lot's of side tracks, here is hoping the install goes smoothly tomorrow and I don't find low lock with "limp mode"
Here are the part numbers for the Front Driveshaft (P52105728AD), Rear Driveshaft (P52105760AE) and Transfercase (P52853391AB).
Note the driveshafts can come out of any Jeep WK or XK as long as it had a NV245 (QT2 or QD2) Transfercase.
However the Transfercase has to be for a 3.7L V6 QT2 equipped WK or XK only.
See the last picture, this is what the input side of the transfercase needs to look line.

[Sal-XK]

Good luck man!

[07JeepXK]

Let us know bro!

[cmdr jim]

It's all in, a fairly easy job. It took me 6 hours, but messing with the passenger side nuts added extra time. Removing the transmission crossmember and lowering the transmission helps, but a 13mm crows-foot makes it happen, I only had a 1/2" but it's interchangeable. The fuel tank skid plate added to the difficulty as well. I had to remove the transfercase motor from the transfercase and bend a corner of the fuel tank skid plate to get the transfercase up past it. I simply bent the corner back afterwards. An adjustable wrench works well for this.
Attached are pictures of the end of the nag transmission, the NV245 and NV140 transfercase and finally a picture comparing the NV245 drivetrain to the NV140 drivetrain. The NV140 is about half the weight of the NV245.
I have tested shifting the transfercase and the transfercase is shifting correctly, next is to test drive it, check for vibrations with the used driveshafts and to test for low lock errors.

[cmdr jim]

Test results so far. No vibrations up to highway speeds. If anything the drivetrain feels tighter. I did notice the NV140 had more backlash than the NV245. My NV140 has 66000 miles and the NV245 only had 11000 miles, that may be the reason. Also, I did a final drain on the NV245 and what oil drained looked very good.
I tested with the Jeep in gravel, High to High lock works and Low and Low Lock work. The speedometer is correct even in Low Lock. No "Check Engine Light" the first time I used Low Lock, I left the transmission in drive.
The second test I shut off the Jeep then restarted and shifted the transmission to 1st gear, I ended up with a Check Engine Light, Code "P0700". I don't think it went into Limp Mode. I shut it off and put the transfercase into High, tried resetting the fault with HyperTech, but it didn't remove the "Check Engine Light", however the Jeep shifted correctly and I can manually shift through all the gears. More testing I need to understand this.

[Sal-XK]

I think you nailed it man awesome work!

[stites-xk]

Awesome work

Sent from my DROID RAZR using Tapatalk 2

[Ross]

Good job!

[cmdr jim]

I think you nailed it man awesome work!

It does look like it's working, I just need to test some more to see what is happening with the codes in Low. I can tolerate error codes when in Low, as long as it doesn't adversely affect anything else.

I think this is what is taking place when I shift to Low or Low Lock:

First it is going into Permanent Limp-In Mode
"If this occurs while the vehicle is moving, the transmission
remains in the current gear position until the ignition is turned off or the shifter is placed in the "P" position. When
the shifter has been placed in "P" the transmission only allows 2nd gear operation. If this occurs while the vehicle
is not moving, the transmission only allows operation in 2nd gear."

And once I shift the transfercase back into high it goes into Temporary Limp-In Mode
"This mode is the same as the permanent Limp-In Mode except if the condition is no longer present, the system resumes normal operation."

Which would explain why after I receive the "Check Engine Light" and shift the transfercase back to high the transmission operates correctly. By going out of Low and back into High, I've "fixed" the condition that put the TCM into Permanent Limp-In Mode, and placed it into Temporary Limp-In Mode.

Question, how long does the error code stay in the TCM, but operate correctly before the code disappears or does it need to be reset by disconnecting the battery?

[LWM]

Question, how long does the error code stay in the TCM, but operate correctly before the code disappears or does it need to be reset by disconnecting the battery?

In most cases it takes three starts of the motor to clear codes as long as the problem has also been corrected (you cannot just start it and turn it off, you must drive between starts).

[cmdr jim]

In most cases it takes three starts of the motor to clear codes as long as the problem has also been corrected (you cannot just start it and turn it off, you must drive between starts).

Just confirming, that appears right. The "Check Engine Light" is off, keep in mind there were never any shifting problems in "High" during the error.

[cmdr jim]

I think I have come up with a way to eliminate the Low Lock error code completely. It would require another wheel sensor and 4 relays. Spot welding equally spaced targets on the rear driveshaft flange up by the transfercase, and mount the wheel speed sensor to the transfercase to read these targets. Then when in Low or Low Lock switch on the relays with my program to read this wheel sensor, instead of the actual wheel sensors.

[07JeepXK]

Good luck with that. lol thats way beyond my knowledge!

[Matt]

I think I have come up with a way to eliminate the Low Lock error code completely. It would require another wheel sensor and 4 relays. Spot welding equally spaced targets on the rear driveshaft flange up by the transfercase, and mount the wheel speed sensor to the transfercase to read these targets. Then when in Low or Low Lock switch on the relays with my program to read this wheel sensor, instead of the actual wheel sensors.

I think I see what you're trying to do.... but that would only work if the gear reduction in the tcase is the same as the gear reduction in the axle (in other words the axle RPM out of the tcase in Low is equal to the wheel RPM when not in Low)..... or did I misunderstand the concept?

[Matt]

That would also mean you have no brake traction control when in Low since the computer will never know if a wheel is slipping...... And it may even set off codes if the programming expects to see different wheel speeds when turning (I believe there's an encoder on the steering wheel.... would have to double check)

[cmdr jim]

That would also mean you have no brake traction control when in Low since the computer will never know if a wheel is slipping...... And it may even set off codes if the programming expects to see different wheel speeds when turning (I believe there's an encoder on the steering wheel.... would have to double check)


I think I see what you're trying to do.... but that would only work if the gear reduction in the tcase is the same as the gear reduction in the axle (in other words the axle RPM out of the tcase in Low is equal to the wheel RPM when not in Low)..... or did I misunderstand the concept?

Under normal running in High and High Lock, the Jeep would look at the 4 wheel sensors at each corner. The rear wheel sensors run on a tone ring with 48 teeth. I assume the front is 48 teeth too, but I need to confirm this before going farther. What I plan on doing is tricking the Jeep into thinking it is seeing the 48 pulses per rev when the transfercase is running the wheels 2.72 times faster. So when I run in Low or Low Lock, the Jeep sees 131 pulses per rev on the wheels, and the Jeep thinks there is something wrong in the transmission because of the low rpms of the engine and transmission and it throws an error code.
My plan is to go to 3.73 gears, so I'll use this as an example of how I'm going to trick the Jeep to think all is correct. However the speedometer with be off in low and Low Lock. I need the Jeep to see 48 pulses, to do this my plan is to make the rear drive shaft upper flange into a tone ring with 5 teeth. Only 5 teeth? Yes, remember I'm on the other side of the differential so that 48 has to be divided by 3.73 (12.87 teeth) and it also has to be divied by the 2.72 ratio of the transfercase 4.73 teeth, round this up to 5 teeth. If the differential was 3.07 the number would be 6 teeth.

Now I will lose the electronic traction control since the way I'm doing this all wheels will appear to be running at the same speed looking at that one tone ring and sensor. Not sure what the steering encoder will do. But keep in mind, I'm adding a manually controlled front ELSD (QD2 differential) and a ARB locker in the rear. In Low Lock I can manually lock up fully. In high and High Lock, the traction control would work normally as it is back to monitoring all 4 wheels and wheel spin. But with the manual lockers I can still elect to be fully locked up.

I think for most people this last option of speed sensor is not needed. You would have Low and Low Lock with traction control and as long as you don't shut off and restart the Jeep, or place it into Park, the limp mode does not affect transmission gears as long as you don't shut off and restart in Low or put the Jeep in Park. And even if you do get into an error code after using Low and Low Lock, once you go back to High and High Lock, shut off and restart the Jeep, the transmission shifts and works correctly. The Engine Error Light will stay on for 3 trips in the Jeep and then disappears.

[Matt]

Got ya... i thought you were going to use the same rings as the ABS and therefore have the same number of pulses, not accounting for the difference in gearing (should have known you already thought of that lol).

And yeah, with lockers the traction control isn't an issue.... for anyone not installing lockers, id live with the check engine light and maintain the traction control otherwise your 4-low will be almost useless with 2 open diffs.

[cmdr jim]

The days of buying the cheap low end model Jeep and upgrading it as you want at are pretty much gone. I bought the XK to be different than the JK crowd, it's becoming very apparent the JK is really the only model left that you can modify the drivetrain. It's unfortunate that's the case. And if it wasn't for AEV, the 2012 JK's equipped with automatic transmission would be stuck with stock gear ratio's. All of these electronics sound good upfront, but without Jeep and Jeep dealer support for modifications (the old days) we are limited.....Don't get me wrong, our Jeeps are very capable, but some of us want more.

[cmdr jim]

Update on some more testing. I start up the Jeep this morning and once the Jeep is running, I shift the transfercase to Low, back out of the driveway and shift the transmission to 1st gear. I drive away and Low feels really good. I get up to about 10 or 12 mph and I feel a shift to 2nd. Yet I still have the Jeep in 1st. The Jeep just went into "Limp Mode" for what I can tell. So I can continue to drive in 2nd gear in Low and all is fine. I stop, but leave the Jeep running and shift the transmission into Neutral. Then shift the transfercase back to Hi. Put the transmission back into drive and I'm in Neutral, I shut the Jeep off and restart it in Park, remember the transfercase is in Hi position, and it now has all transmission gears and drives and shifts correctly, with no "Check Engine Light". I do this again to test it all out and it reacts the exact same way in Park as well. Obviously the Jeep is going into "Temporary Limp Mode" when I'm in Low and once I stop and shift the transmission into Neutral or Park, it goes into "Loss of Drive Mode" shifting the transmission into Neutral to protect the drivetrain because of the miss-matching output speed. Once I shift the transfercase back to HI, shut off and restart the Jeep the "problem" goes away and it releases "Loss of Drive Mode" and never do I receive a "Check Engine Light".

So where this all leads? We can't have fully functioning Low or Low Loc in 1st gear.....This also means if you were to swap in another Jeep or Atlas transfercase, you would still have the issue of no 1st gear in Low or Low Loc. Adds another degree of difficultly to all of this. Do I have fully fuctioning Hi Loc, yes. Could I live with Low Loc and 2nd gear possibly?

To make this work correctly for everyone, what really needs to happen is to have an additional tone ring and wheel sensor at all 4 corners that can be switch to when in Low or Low Lock. Then Traction Control, and Low Loc would work correctly. I know how to switch between the wheel sensors, but where to mount the tone rings and sensors? The tone ring count at each wheel is 48 stock, I confirmed that last night, the front and back are the same count, the additional tone ring would need to be 18.

[Sal-XK]

Have you reprogrammed the computer? The super chips allows you to program TC gear ratios as well as the axel gear ratios.

[Matt]

.....Don't get me wrong, our Jeeps are very capable, but some of us want more.

I would like the ability to manually control my front/rear lockers so I can put them in full-lock at the push of a button

[cmdr jim]

Have you reprogrammed the computer? The super chips allows you to program TC gear ratios as well as the axel gear ratios.

I had the same thought, just hook up the programmer to change the gear ratio lower when in Low Lock and when finished program it back.
I have a HyperTech Max Energy programmer, I thought that was the only Programmer for 3.7L V6's. It goes down to 5.13 ratio, I need much lower:
For 3.07 in Low it would need to be 8.35
For 3.55 in Low 9.66
For 3.73 in Low 10.15
Anticipating a possible gear ratio issue in Low, I emailed HyperTech a while back to see if they would add these ratios to my Programmer and problem solved right? Nope, no custom programs is what I heard back. This would have been the simplest solution to it all......

[Matt]

Changing the ratio would be a bit of a pita every time you switch back and forth anyway (well unless you leave it in the whole time).

I wonder if you could add some sensors to the CVs up front near the diff..... the rear would be a bit more challenging

[cmdr jim]

Changing the ratio would be a bit of a pita every time you switch back and forth anyway (well unless you leave it in the whole time).

I wonder if you could add some sensors to the CVs up front near the diff..... the rear would be a bit more challenging

I agree, any ideas on location and mounting would be greatly appreciated.


I know how to switch between the wheel sensors, but where to mount the tone rings and sensors? The tone ring count at each wheel is 48 stock, I confirmed that last night, the front and back are the same count, the additional tone ring would need to be 18.

[cmdr jim]

I would like the ability to manually control my front/rear lockers so I can put them in full-lock at the push of a button

That may be possible. Once I work through all of this. And keep in mind I have a way to manually lock a front ELSD, but I also don't have all the electronics trying to control it as you do in your Jeep. Not sure if you would get error codes bypassing the electronics?

[cmdr jim]

Doing some more reading in the service manual, the actual "Limp Mode" the Jeep is going into is this mode, after I shift the transmission to Neutral or Park.

Loss of Drive "Mode"
If the TCM detects a situation that has resulted or may result in a catastrophic engine or transmission problem, the transmission is placed in the neutral position. Improper Ratio, Input Sensor Overspeed or Engine Overspeed DTCs cause the loss of drive.

I have gone back up to my post from this morning's update and revised the statements accordingly.

[cmdr jim]

How about this at each corner instead of trying to mount an additional tone ring and wheel sensor. I could use the relay to switch the signal to either allow straight off the wheel sensor (Hi Positions) or direct the wheel sensor signal through this conditioner to reduce the wheel sensor pulses for the 2.72 reduction?
It has that reduction number I need 0.368. I could test this out with just one, and have it send a signal to each corner. Granted, it wouldn't allow for Traction Control since in the test all corners would be the same.

http://www.dakotadigital.com/index.cfm/page/ptype=product/product_id=126/category_id=311/home_id=59/mode=prod/prd126.htm

[Matt]

I was actually going to mention signal conditioning earlier.... but wasn't sure if its possible to manipulate a pulse like that? (I'm sure my advanced equations professor would slap me for saying that and remind me of a basic Fourier transform that could do it....)

[Matt]

..... and the fact that an $85 off the shelf component can do it makes this idea very promising!

[cmdr jim]

..... and the fact that an $85 off the shelf component can do it makes this idea very promising!

Put those ideas out here! Thinking outside the box. My thoughts as well, I found one on ebay for $80.70, I can't make many parts for $80.70. Now is the wheel sensor a square wave pulse? And does this conditioner do square waves?

[Matt]

I'm not an electrical engineer.... but its just a hall effect sensor which is (I believe) a square waveform..

If the conditioner simply gives an output based on a multiplication of the input waveform pulse count, which it sounds like it does, most of the work is done. Just need a way to control the conditioner "on the fly"...

[cmdr jim]

I'm not an electrical engineer.... but its just a hall effect sensor which is (I believe) a square waveform..

If the conditioner simply gives an output based on a multiplication of the input waveform pulse count, which it sounds like it does, most of the work is done. Just need a way to control the conditioner "on the fly"...

I'm pretty sure you are correct on the Hall Effect switch. I'm not electrical either, just a mechanical engineer. I have an email into Dakota Digital. It appears our wheel sensors are +12vdc powered and the return signal is -12vdc. Reading their manual, it talks a lot about two wire, but one of the wires being ground and the other being the signal.

I have a way to switch between the two. Using my PLC and changing the program slightly. I can control relays to "toggle" between the two. Running the wheel signals through the conditioner if in Low range, and then bypassing the conditioner if in Hi range. I'm thinking this is all possible. Just waiting on a reply back from Dakota. Thanks Matt for the help!

[Matt]

I'm actually working on my masters now (one class at a time!) and my professor is an electrical/controls PhD.... I should get his input. I'm sure he's consulted for much more complicated systems (actually I'm positive of that)

[Matt]

Good news... at lecture now and my professor is on board.

[cmdr jim]

Cool, stick with the Masters program. I've been designing automated equipment for 20+ years, I wish I had stuck with it when I had the chance.

[Matt]

I hear ya. I'm trying to knock it out before the kids get old enough for sports and I really have no time!

[ScorpionCrawler]

This has been a fun read, I'm maybe getting 30% of what you are saying but am hoping for the day that you say it's dialed in the way you want it to be.
Great build, great thread, keep up the good work and info and GOOD LUCK!!

[Matt]

Ok there's definitely a few options but we have to do a bit of homework to determine which are viable. It all depends on what the computer is doing with the signal. If the computer is "dumb" and only cares about pulses (on/off/on/off/etc) then there are some simpler options. However, like eluded to in the Dakota Digital link, the computer may be analyzing the entire signal- not just PPM but other parameters such as pulse width which would be affected by some simpler conditioning methods.

So we'd have to check the schematics to see where the speed sensor signals are going (which modules) and try to figure out what the module(s) are looking for.

**something quick/fun to try that would only help someone with controllable lockers; what would happen if all 4 sensors are unplugged? Wondering if that would prevent limp mode and just throw ABS/TCS lights, thereby allowing you to wheel in 4-low?

[cmdr jim]

Here is a bit more information from the service manual about the Wheel Sensors:


SENSOR-FRONT WHEEL SPEED
DESCRIPTION
A wheel speed sensor is used at each wheel. The front sensors are mounted to the steering knuckles. The rear
sensors are mounted at the outboard end of the axle. Tone wheels are mounted to the outboard ends of the front
and rear axle shafts. The gear type tone wheel serves as the trigger mechanism for each sensor.
OPERATION
The sensors convert wheel speed into a small digital signal. The ABM sends 12 volts to the sensors. The sensor
has an internal magneto resistance bridge that alters the voltage and amperage of the signal circuit. This voltage
and amperage is changed by magnetic induction when the toothed tone wheel passes the wheel speed sensor. This
digital signal is sent to the ABM. The ABM measures the voltage and amperage of the digital signal for each wheel.

Not sure what this all means.

[Matt]

That's not really saying much...


The sensors convert wheel speed into a small digital signal.
I'm sure you know this already, but others might not.
This just says what the sensor does.... wheel speed means the tone ring is rotating, as it rotates the sensors reads that and creates the digital signal which is merely a square waveform.


The ABM sends 12 volts to the sensors. The sensor has an internal magneto resistance bridge that alters the voltage and amperage of the signal circuit. This voltage and amperage is changed by magnetic induction when the toothed tone wheel passes the wheel speed sensor.

This is just the written description of the hall effect sensor. The magnetic field changes as the teeth of the tone ring pass.... on/off/on/off/on/off/etc. The change in magnetic field takes the standard input voltage and creates a fluctuating output. It's this output (voltage and magnitude) that we need to figure out..


This digital signal is sent to the ABM. The ABM measures the voltage and amperage of the digital signal for each wheel

The bold is the important part.... the voltage and amperage measurements indicate the module is concerned with more than just the number of pulses in a given period of time. This would make sense now that I think about it since there are DTC's for high/low sensor voltage....

[cmdr jim]

Here is the Wheel Sensor Schematic and the SGI-5 wiring diagram. I assume it's a matter of cutting the wheel sensor signal wire to the signal input of the SGI-5 and then connecting the the ABM side to the Out1 or Out2.
Most of the electrical diagnostics are checking wheel sensors deals with for voltage above 10vdc, and shorts to ground or voltage. Matt pm me with your email and I'll send you a pdf of of the section to look at if you're interested.

[Matt]

Just checked out some of the info.... im still iffy due to the way our vehicles use the signal. I'd contact them and ask for specifics on why they don't recommend using their device for ABS signals. I presume it has to do with some of the concerns my professor brought up today; specifically if the module is reading the leading & trailing edges of the waveform and using frequency calculations to determine wheel speed as opposed to the number of pulses. Amplitude calculations of the output waveform will also give an indication that the input voltage is compromised.

[cmdr jim]

Just checked out some of the info.... im still iffy due to the way our vehicles use the signal. I'd contact them and ask for specifics on why they don't recommend using their device for ABS signals. I presume it has to do with some of the concerns my professor brought up today; specifically if the module is reading the leading & trailing edges of the waveform and using frequency calculations to determine wheel speed as opposed to the number of pulses. Amplitude calculations of the output waveform will also give an indication that the input voltage is compromised.

I'm iffy as well, I just don't understand the way the signal is process. However I do think it's a liability issue for Dakota and for them to state it is not to be used with ABS takes them out of that situation.
My plan was never to use the controller for on road use. For off road use only per my first post. With the controller power turned off for on road use. That would be the same for the SGI-5, no signal conditioning for on road use, which would not influance ABS. I don't thing we need anti-lock brakes running at low speeds offroad, if signal conditioning would affect it.

I sent you another email, showing the way I would go forward testing with a single SGI-5 and 4 relays to allow my PLC program to switch between stock wheel sensor signals and conditioned signal. Going farther, it would require a SGI-5 for each wheel sensor to maintain Traction Control.

[Matt]

It's not really a matter of "needing" ABS or a liability im concerned about... its how the signal is processed and what sending a modified waveform into the ABM will do. You may find you'll do all this work and end up with limp mode again; in which case you may be better off just disconnecting the sensors (figuratively with a switch).

[cmdr jim]

It's not really a matter of "needing" ABS or a liability im concerned about... its how the signal is processed and what sending a modified waveform into the ABM will do. You may find you'll do all this work and end up with limp mode again; in which case you may be better off just disconnecting the sensors (figuratively with a switch).

Unplugging wheel switches is easy enough to do, I'm thinking it will go into a ABS error of some sort, but it's a quick test.
Do you think there is there a way to tap into a wheel sensor to see what signal is being sent to the ABS module?

[Matt]

There is a way to tap into the signal.... but that's the easy part and doesn't answer the question of what the ABM is doing with the signal. If its just counting pulses there's no problem, whereas if its analyzing the waveform (probable for present day electronics) then we'll have an issue.

I guess the only way we'll really know is to test it out like you drew up......

[cmdr jim]

I think you are right, testing it may be the only way....another $80.

Getting back to your manually locking ELSD question. Keep in mind, I don't have all the electronic features to lock and unlock the differentials as you do with the FDCM. The ELSD is electro-hydraulic operated, and applies a pressure to a clutch pack. Your Jeep uses a PDM to control voltage to the solenoid to vary the pressure on the clutch pack and does this as required for the different inputs it is receiving from the wheel sensors, engine, transmission, etc. It also monitors the resistance to determine how hot the differential is getting and will back off on the useage if it gets too hot. A lot is going on there.

I have done a number of test on a soleniod out of the ELSD and it is high temperature rated, over 350 degrees F. I have tried to kill it with time, but at over an hour of on time and temperatures stabilizing around 300 F, I couldn't. I started testing with an adjustable PDM but found out shorty, it's not needed if all I'm going to do is apply full pressure to the clutch pack. For my use, it's really quite simple. I am going to use a 12vdc voltage regulator and a relay and switch. The solenoid pulls under 1 amp at 12vdc (I could probably get by without the relay) Then just turn it on with the switch when needed and shut it off when not. The key here is not to keep it energized for more than 20 to 30 minutes to stay away from any heat issues.

If you wanted, I would start a test by just unplugging both your front and rear ELSD solenoid wires and shut off Traction Control and see what errors you get. If you get some, plug the wires back in and drive it, see when the errors go away. If they do, your next step would be to find a DPDT relay or use 2 relays. I think you want to disconnect both the positive and negative wires going to the FDCM from the ELSD solenoid when powering it with straight 12vdc. Nothing getting back to the FDCM period.

In the picture I show the solenoid hooked up to a power supply, shortly after that picture I had to hang the solenoid from the desk or it would have burned the desk. I ran numerous tests and couldn't kill it with duration or temperature.

[Matt]

I was following you ELSD thread... I believe on the commander forum?

Agreed, there are a lot more limitations from my end. Probably worthy of a whole new thread. :)

Since its more of a "nice to have", I think energy should stay focused on the QTII tcase conversion. Not to mention, the results if your testing could be the solution for manually controlling the ELSDs on vehicles already equipped. In case the idea didn't already pop into your head..... we may be able to trick the computer in thinking one front and one rear wheel is slipping so it engages the diff. (Unknown would be if we get errors after diff is engaged and wheel speeds are still off.... lol another thread for that)

[cmdr jim]

Yup, on the other forum....

I ordered a SGI-5 and am planning on testing next week some time. I think at first I will set it up to run on only one wheel sensor. I can have it condition the signal at a ratio of 1 to 1. If it functions properly I'll add in the other 3 wheel senors and test Low Lock.

My email back from Dakota states there are two possible outputs from the SGI-5:

Technically all of the outputs on that unit are a square wave. *The difference on them being the A/C outputs are above and below ground (-6V to +6V), and the open collector outputs will be all above ground with voltage dependant on the pull-up provided (0V-12V if a 12V pull-up).

So as long as the ABM isn't looking for something other than these two types of input it should work....

[cmdr jim]

The SGI-5 came in yesterday, I hooked it up to a front wheel sensor and I can't get it to see a signal. I went through the troubleshooting section of the manual, I get a constant green light on the SGI-5, which means no signal. I tried all the changes suggested in the manual and could not get a signal from the wheel sensor. Also while running off the SGI-5 without a signal, the anti-lock brake error and no traction control lights came on immediately and stayed on until I reconnected the wheel sensor back to normal. My guess is the wheel sensor is sending a signal the SGI-5 doesn't recognize.
I think I'm back to setting up a wheel sensor to switch to when in Low Lock.

I have an email into Dakota Digital tech support.

[Matt]

That's strange.... the signal of the speed sensor shouldn't be anything fancy. You went for a test drive with it?

Did you maintain the input voltage for the sensor and just tap into the return signal?

[cmdr jim]

That's strange.... the signal of the speed sensor shouldn't be anything fancy. You went for a test drive with it?

Did you maintain the input voltage for the sensor and just tap into the return signal?

Yes and Yes. I did find this explanation of "Active WSS Sensors" on the internet this morning, which may shed light to why the SGI-5 can not see a signal.


ACTIVE WSS SENSORS
In recent years, several new types of “active” WSS sensors have appeared. These are used on many 1999 and newer Chrysler, Jeep and Mercedes models with Teves Mark 20e and up Teves ABS systems. Active WSS sensors are also found on the Ford Focus, Toyota Tundra and other applications. This type of sensor is becoming more common on late-model vehicles because of its greater accuracy at low speeds.
Active WSS sensors, which Chrysler refers to as “magneto-resistive” sensors, work like a “Hall effect” sensor and generate a square wave on-off digital signal that changes frequency with wheel speed. This type of sensor detects the change in magnetic polarity (flux) as the teeth on the tone ring or small magnets pass under it. Small magnets may be built into the wheel bearings or bearing seal for the WSS sensor to read.
Active sensors often have three wires: a voltage reference input (5 to 12 volts), a signal output and ground. But some active sensors have only two wires (reference voltage and signal return).
How can you tell a 2-wire active sensor from a 2-wire passive sensor? Turn the ignition on and backprobe both wires with a voltmeter. If you see a voltage reading (5 to 12v), you have an active WSS sensor. If you see no voltage (0v), you have a passive WSS sensor.
Active WSS sensors also have an integrated circuit within the sensor itself that converts and amplifies the signal before it goes back to the control module. This allows the sensor to read wheel speeds all the way down to zero mph (which improves ABS control at low speeds as the vehicle comes to a halt).
When the key is on, an active WSS sensor has two states: low and high. In the low state, it generates a fixed 0.9 volt return signal of about 7 milliamps. In the high state, it generates a signal of 1.65 volts and 14 milliamps. The rate at which it toggles back and forth between its high and low states corresponds to the speed of the wheel.
This type of sensor must be connected to its wiring harness to test it, and the ignition key must be on so the control module can provide reference voltage to the sensor. If you forget and leave the key off, you won’t get any output from an active WSS sensor.
Because of the added electronic circuitry inside the sensor, and active WSS sensor cannot be tested with an ohmmeter like a passive WSS sensor. You have to look at its output signal when the wheel is turning and the ignition is on. This can be done with a scan tool (look for a mph reading while spinning the tire or during a test drive), with a voltmeter (turn the wheel very slowly and look for a change in the voltage output from high to low), with a NOID light (the LEDs on the NOID light will flash when it detects a signal pulse), or a DSO. The waveform on the scope should show a square wave pattern that changes from low (0.9v) to high (1.65v) as the wheel turns. The difference in height of the waveform should be 0.75 volts (1.65v minus 0.9v).

[07JeepXK]

It's been awhile. Any updates on this????

[cmdr jim]

It's been awhile. Any updates on this????

Working too much overtime and it's been on the back burner till I have time to address it. The SGI-5 didn't work for conditioning the wheel speed sensors. These sensors are the newer Chrysler type and the SGI-5 doesn't put out the correct signal.
I have an idea of placing an additional speed sensor at the front differential and switch to it when in low, but the speed sensor would be 2% off from real and I don't know what the Jeep will do with 2%. Plus it would feed all 4 wheel locations, so being fully locked up would be needed. Or figure out how to place individual sensors and tong rings at each corner, switching to those when in low.
Other than that, I can use low, but it puts the transmission into third gear quickly and if I shift to park or neutral, I lose all gears and have to put the transfercase back into high to fix it. Then it drives normally, until I repeat going into low. I do have a fully locking high which is nice.....

[07JeepXK]

So basically everything is fully functional for normal daily driving correct? If so at least you have made it this far!!!

[cmdr jim]

So basically everything is fully functional for normal daily driving correct? If so at least you have made it this far!!!

Yes,I have been driving it since the day I installed the transfercase.
My controller works, and shifts the tcase correctly everytime. I have full manual control of the tcase and have high lock, just error codes in low or low local.

[Ross]

Have you gotten a chance to try the new t-case offroad?

[07JeepXK]

It sounds like he's getting error codes when he engages 4 low limiting him to 3rd gear.

[cmdr jim]

It sounds like he's getting error codes when he engages 4 low limiting him to 3rd gear.

This is correct.

[cmdr jim]

Have you gotten a chance to try the new t-case offroad?

Not yet, but having a locked high transfercase has to be better than an open center.

[valpacer]

Little off topic here but i thinking if any knows , you will!

Are the JK tone rings the same as the WK?

[cmdr jim]

Little off topic here but i thinking if any knows , you will!

Are the JK tone rings the same as the WK?

Not sure on the JK but ours have 48 teeth and are part of the hub bearings at each corner. Looking at swapping in JK axles?