Rear E-Locker

[SR1355]

I've searched thru a few threads but with no luck. Has anyone successfully bypassed the lo-4wd control of the rear locker?

[HummerHippy]

I'm no mechanic, so I am not sure why you want to by pass this, but I have a switch above the radio, where the 4hi lock, 4Low Lock etc buttons are. One is to engage/disengage the rear locker. And as far as I know, the rear locker is only available in the 5speed manual trans.

[Sewie]

I'm no mechanic, so I am not sure why you want to by pass this, but I have a switch above the radio, where the 4hi lock, 4Low Lock etc buttons are. One is to engage/disengage the rear locker. And as far as I know, the rear locker is only available in the 5speed manual trans.

The locker is availabe with either transmission and the bypass he's referring to is so that it can be engaged in 4Hi-Lock. From the factory, you can only engage the rear locker when in 4Lo and it automatically disengages if you go over 20mph, IIRC.

There was some talk about this on here before. But I haven't seen anyone post that they have successfully bypassed it in the H3 yet.

[SR1355]

Right on, there are plenty of times that I'd like the rear locker locked in 4-HI, dune riding, mud running, snow.... Anyone had any success?

[Idaho-Hummer]

I have not done this but the whole car runs on a 12-Vdc system. Just find the wire that goes to the e-locker and tap with a volt meter and turn it off and on and then hook up a switch. that should do it. give it a try and then let me know if it works.

[f5fstop]

What's 12V DC have to do with it. If it was a 6 volt system it would work the same, or a new 42 Volt system?

Yes, there is a way to bypass it and it requires more than one wire, or you will light up the DIC and set codes.

[SR1355]

f5fstop, do you have more info than that? I sure would like to work around this limitation.

[HummBebe]

Right on, there are plenty of times that I'd like the rear locker locked in 4-HI, dune riding, mud running, snow.... Anyone had any success?

Don't really want to interject here, but...

With the full time 4WD, and the traction control system, in the situations you describe, I just don't understand why you would need it?

[f5fstop]

Don't believe you would need it at speeds above 20 mph. The locker is supposed to be used for low speed applications; thus the 20 mph unlock. It might cause damage to the rear locker, which from my experience reading forums, means the person will remove the bypass and hit GM for the warranty.

We already have enough legitimate hits on warranty for the front axle...:clapping: and that is GM's fault.


So, even though I know how, I won't say how.

[yzergod]

Too bad. The guys with a Jeep Rubicon figured it out and gladly share the info on how to. Seems like a valid reason for wanting to be locked in 4Hi IMHO.

[Sewie]

Too bad. The guys with a Jeep Rubicon figured it out and gladly share the info on how to.

Are they Jeep / DC employees?

[ChevyHighPerformance]

The e-locker is controlled by the transfer case shift control module. This module monitors both the control and return voltages from the e-locker actuator and if they are incorrect DTC-C0388 is set and SERVICE 4WD is displayed. The control module also has a free wheeling diode to accomodate the e-locker's actuator coil's inductance. The e-locker's coil normal resistance is between 2.2 and 4.3 ohms.

[yzergod]

Are they Jeep / DC employees?

I'm sure some were in the beginning. But now it is so common that aftermarket companies are offering kits. DC stated that they did not want to offer it as an option due to liability reasons (i.e. soccer mom munching rear diff in mall parking lot because she hit button accidentally) just like f5fstop stated above.

My point is that it (should) be an easy fix for somebody to figure out and the reasons stated for wanting to do it are sound. I completely understand why f5fstop doesn't want to publisize how to do it and I wasn't giving him crap. I just said it was too bad that there wasn't a quick fix out there as the original poster's reasons for wanting to do it seemed logical to me. I'm sure somebody will eventually post how to do it. If you're stupid enough to do the fix and then munch your locker, then I agree you shouldn't claim it under warranty. But, just because GM (or Jeep) doesn't offer it that way from stock is no reason to discourage somebody from doing it IMHO.

Geez, you guys are sure quick to jump somebody's ass if they don't follow the norm like sheep around here!:popcorn:

[HummBebe]

Geez, you guys are sure quick to jump somebody's ass if they don't follow the norm like sheep around here!:popcorn:
Ya think???

I simply stated that there are two other systems that would cover the needed traction in the situations you described.

How is that jumping your ass?

Hummers are more sophisticated vehicles. Comparing them to an outdated redneck system the likes of which Jeep uses is just well.....dumb. They are different. Period.

:popcorn::popcorn:

[yzergod]

Ya think???

I simply stated that there are two other systems that would cover the needed traction in the situations you described.

How is that jumping your ass?

Hummers are more sophisticated vehicles. Comparing them to an outdated redneck system the likes of which Jeep uses is just well.....dumb. They are different. Period.

:popcorn::popcorn:
Yeah, I think.

Actually, I wasn't refering to your reply. But, you jumping in kinda proves my point.

It is funny in that I wasn't comparing apples to oranges. I agreed with the original poster that you should be able to bypass the system and that his reasons for wanting to seem valid. The fact remains that even though "Hummers are more sophisticated vehicles", there should be a way to do it. And if the guy wants to, he'll find way. I bought a Lux/Adventure over the Rubi. I'm one of you guys. I just don't share in the elitist attitudes that stock vehicles (no matter how "sophisticated" they are) should remain stock because thats how our lord god Hummer wanted them to be. If there are improvements to be had by tinkering under the hood in the effort of better off-roading, I'm all for it. But, as stated, I was not giving f5 attitude for not giving it up. He is a valuable asset to this board and has helped me out. I would not want him to jeopordize his job over a questionable mod. (Least of all for somebody else instead of me :D.)

You guys are a trip. I suppose that if I wanted to crank on my torsion bars a couple of turns to run bigger than stock tires, you'd poo-poo it because it isn't how it came from the factory? Give me a break.

You need to see how some of you long timers come across sometimes. Holy crap!

[HummBebe]

Just because you can ...doesn't mean you should:p

[HummBebe]

Oh and I run 35's with 5 turns, kicks ass on the Rubicon:excited:

[yzergod]

Oh and I run 35's with 5 turns, kicks ass on the Rubicon:excited:
My next mod. Going with 35" BFG/MT's. Was going to try 2.5 turns first. And, Moab is a couple hours from me.:jump:

[HummBebe]

Too bad. The guys with a Jeep Rubicon figured it out and gladly share the info on how to. Seems like a valid reason for wanting to be locked in 4Hi IMHO.

So does that mean the Jeep guys are "cooler" than we are??

And you still have not address the need. Why when you have Traction Control and Stabilitrac?

[HummBebe]

:popcorn:

[HummBebe]

Yeah, I think.

Actually, I wasn't refering to your reply. But, you jumping in kinda proves my point.

It is funny in that I wasn't comparing apples to oranges. I agreed with the original poster that you should be able to bypass the system and that his reasons for wanting to seem valid. The fact remains that even though "Hummers are more sophisticated vehicles", there should be a way to do it. And if the guy wants to, he'll find way. I bought a Lux/Adventure over the Rubi. I'm one of you guys. I just don't share in the elitist attitudes that stock vehicles (no matter how "sophisticated" they are) should remain stock because thats how our lord god Hummer wanted them to be. If there are improvements to be had by tinkering under the hood in the effort of better off-roading, I'm all for it. But, as stated, I was not giving f5 attitude for not giving it up. He is a valuable asset to this board and has helped me out. I would not want him to jeopordize his job over a questionable mod. (Least of all for somebody else instead of me :D.)

You guys are a trip. I suppose that if I wanted to crank on my torsion bars a couple of turns to run bigger than stock tires, you'd poo-poo it because it isn't how it came from the factory? Give me a break.

You need to see how some of you long timers come across sometimes. Holy crap!

You're kinda wordy aren't ya? :giggling:

[yzergod]

So does that mean the Jeep guys are "cooler" than we are??

And you still have not address the need. Why when you have Traction Control and Stabilitrac?

Cooler, no (especially how you basically owned Moab on things the Jeep guys run away crying from :giggling: ). A bit more open to sharing thoughts on improving factory stuff... maybe. ;)

I'm no expert with sand, but Traction Control and Stabilitrac doesn't seem like it would be of as much a benifit as a locked rear in a 60/40 set-up. Snow and ice yes. Mud? Who cares... only rednecks play in mud.

[yzergod]

You're kinda wordy aren't ya? :giggling:

I'm at work and I get paid by the hour... :fdance:

[HummBebe]

It's designed to prevent driver error, it detects spin and sends power to the opposit wheel.

I've run sand, a little snow, and some serious mud (probably won't do that much). With the BFGs in sand and mud, it was awesome.

No worries. Only Sewie got stuck:giggling:

[Sewie]

Only Sewie got stuck:giggling:

Good thing you were at the bottom to get pics. :OWNED:

[Sewie]

.....Geez, you guys are sure quick to jump somebody's ass if they don't follow the norm like sheep around here!:popcorn:

Who exactly is jumping on your ass? :confused:

[ChasH3]

Good thing you were at the bottom to get pics. :OWNED:

Hey, I saw that picture... I think Sewie was just taking a break he wasn't really stuck..... :beerchug:

[Crash ?]

I'm a LONG way from being an expert on much of anything.. But my observations in sand was that the H3 did much better in 4Hi Lock with the traction control turned off.. With the traction control on it kept feeling like the motor was bogging down.. In 4Lo I had plenty of power, but no speed.. 4Hi Lock with traction control turned off, the truck would stand up and go...

On the rear E-Locker... Eaton makes a locker thats designed to be used on the drag strip.. Granted we're not on the drag strip, but there's not a soul here putting 500hp to the rear wheels either.. If Eaton's will hold up on a 500hp dragster, GM should be able to make one that'll stand up to the power an H3 can dish out... Of course you think they'd make a Front diff that would hold up to though...

As far as being able to bypass the setup to get it to work, it shouldn't be to much of a problem for any decent mechanic that's familiar with electronic transfer cases and e-lockers.. Just remember that most decent mechanics do that kind of stuff to make a living.. You may end up having to drop a bit of change to get it done right..

Rob

[HummBebe]

Good thing you were at the bottom to get pics. :OWNED:

Until I blew right past you.....


:OWNED:

[Sewie]

Until I blew right past you.....


Whatever SloMo....:rolleyes: :fdance:


And the video evidence does not support your crazy theory. :OWNED:

[HummBebe]

Whatever SloMo....:rolleyes: :fdance:


And the video evidence does not support your crazy theory. :OWNED:

Don't cry baby, :crying: we all know you're the best H3 wheeler:giggling:

[f5fstop]

I'm a LONG way from being an expert on much of anything.. But my observations in sand was that the H3 did much better in 4Hi Lock with the traction control turned off.. With the traction control on it kept feeling like the motor was bogging down.. In 4Lo I had plenty of power, but no speed.. 4Hi Lock with traction control turned off, the truck would stand up and go...

On the rear E-Locker... Eaton makes a locker thats designed to be used on the drag strip.. Granted we're not on the drag strip, but there's not a soul here putting 500hp to the rear wheels either.. If Eaton's will hold up on a 500hp dragster, GM should be able to make one that'll stand up to the power an H3 can dish out... Of course you think they'd make a Front diff that would hold up to though...

As far as being able to bypass the setup to get it to work, it shouldn't be to much of a problem for any decent mechanic that's familiar with electronic transfer cases and e-lockers.. Just remember that most decent mechanics do that kind of stuff to make a living.. You may end up having to drop a bit of change to get it done right..

Rob


Damn, for enough money you can get anything you want. I would imagine that the Eaton locker on the drag car is considerably different than the Eaton locker (AAM Diff) that comes on the H3. Let's just compare apples to apples, and not to oranges in the future.
As for the technicians who do that for a living...take the damn H3 to them and have them to the bypass; I really don't give a flying rat's a** what you or your so-called technicians do with the rear locker.

[HummBebe]

Would ya just say it.....please.....let it fly...K?? :giggling:

[DURAMAX TIM]

back on TOPIC, I'd like to get the e locker to work anytime too.

I was going to try it on the H2 before we got rid of it.

Always get tired of having to keep locking it in after blast through mud holes.

I also know how trucks w/ dual detriot locker drive on snow and ice, have to be a little careful on curves.

I'll have to see if my EFI live can clear codes in the H3, if it does, I'll just reset them after playing.

[HummBebe]

Snow and Ice = Stabilitrac

Sand, Mud or loose soil = Traction control


For fcks sake:rolleyes:

If you need a locker at those speeds, I'd venture you are over using it at lower speed too.

Please tell me what I am missing here???

[westhillsat]

Yeah, I think.

Actually, I wasn't refering to your reply. But, you jumping in kinda proves my point.


You guys are a trip. I suppose that if I wanted to crank on my torsion bars a couple of turns to run bigger than stock tires, you'd poo-poo it because it isn't how it came from the factory? Give me a break.

You need to see how some of you long timers come across sometimes. Holy crap!


You need to read around the forums more ;) :D

Lots of us have already cranked and many have 35's :clapping:


:popcorn:

[marin8703]

if you want to do ithis its probably not difficult at all. Just take a voltmeter and probe the wires out of the locker and see what their status is when in hi(unlocked), hi(locked), low(locked). Play around with diffrent settings and make sure you know what is what.

Locking the diff is probably the easy part, appliying votage where necesary. The other part of not setting codes is harder, but if im on the rite track it should be easy. Since you know what the voltages, resistance or what ever else may chage, just duplicate that condition on the wires going back to whatever is controling the locker, so that its fooled into thinking the locker is unlocked. Do this simulation with a battery or some electronic tinkering things:) .

I am not saying this will work, but if you are desperate its worth a try, and I personally (with my limited knowledge:o ) think it might work. However, as many have said you can ruin your locker (or something else) by using it when your not suposed to.

I personally would not have the locker engaged at any speed even on sand, snow, ice or whatever. I would just leave it to the TC, stabilitrack. The reason I say this is because engineers with far greater knowledge than most of us have designed this vehicle, and if they think it should be this way then im for it. Although lawyers might have had something to do with the engineering process. However you are your own person and you have your own truck so you have the freedom to do whatever you like (just remember GM will not be responsible for repairing any damage), thats why you paid for it.

If you actually do this and something, anything, goes wrong, dont be looking for me afterwards.:D

Oh and by the way, does the H3 have Traction Control and StabiliTrack, or just Traction Control?

[DURAMAX TIM]

Snow and Ice = Stabilitrac

Sand, Mud or loose soil = Traction control


For fcks sake:rolleyes:

If you need a locker at those speeds, I'd venture you are over using it at lower speed too.

Please tell me what I am missing here???

At a HH they had a pretty tall steep muddy hill and said the H2s wouldn't make it up only H1s (H1 w/ wore tires couldn't even make it up).

I followed the lead H1, needed a little run but had a creek at the bottom so couldn't get much speed. low range everything locked TC on normal.
It kept pulling the engine down from all the slippage, still made it up but barely.
went down and tried it later after the stock H2's and one H1 couldn't make it up. turned to TC2 to allow slip and worked much better w/ more speed.
w/o locker it may not have made it. there was two of us running true mud tires (both of us made it), the others were stock TA, only way for them to make it was run on the sides where it wasn't muddy and not as step.


I like to decide when I want to run e locker not GM's lawyers.

[Urban Ops]

:popcorn:

[HummBebe]

At a HH they had a pretty tall steep muddy hill and said the H2s wouldn't make it up only H1s (H1 w/ wore tires couldn't even make it up).

I followed the lead H1, needed a little run but had a creek at the bottom so couldn't get much speed. low range everything locked TC on normal.
It kept pulling the engine down from all the slippage, still made it up but barely.
went down and tried it later after the stock H2's and one H1 couldn't make it up. turned to TC2 to allow slip and worked much better w/ more speed.
w/o locker it may not have made it. there was two of us running true mud tires (both of us made it), the others were stock TA, only way for them to make it was run on the sides where it wasn't muddy and not as step.


I like to decide when I want to run e locker not GM's lawyers.

TC 1 = 4hi lock ?
TC 2 = 4lo lock ?

Or is it the other way around?

When you have an H3 in 4lo lock, the stabilitrac system is disabled.
However, the traction control system still operates.

In 4hi lock, both systems are available.These system are "smarter" than an engaged e-locker.

I can't speak for an H2.

In that type of situation, I would venture to guess a locker would have swept the vehicle sideways at a higher speed.

Lawyers protect large companies from making really big mistakes.

It could also be that the system was tested to the point they knew Stabilitrac and Traction Control were the better alternative, both for people and vehicle components.

[DURAMAX TIM]

TC 1 = 4hi lock ?
TC 2 = 4lo lock ?



TC 1 is standard
TC 2 allows wheel spin and keeps the brakes from slowing the spinning wheels for mud and snow.

I always used e locker and TC2 in 4 low so don't know if TC2 worked in HI lock or open.

I just don't want TC to slow the wheels down when u need the wheel spin and the e locker is going to keep the rear tires same speed so the TC won't slow one rear wheel if it's turning faster because it has a little less traction.

will the e locker work in 4 hi in the H3?

[fw888]

where is the traction control ? i know there is only a button for stabiliztrack on the control panel..

[HummBebe]

will the e locker work in 4 hi in the H3?

No. It will disengage at 20MPH.

So can you go over 20MPH in TC 1?

[HummBebe]

where is the traction control ? i know there is only a button for stabiliztrack on the control panel..

That is because the Traction Control system is always on. You cannot turn it off.

Where is it? In the puter:D

[ChevyHighPerformance]

Wow, strong opinions either way - I don't know what the right answer is, but I will add it is very difficult to design a traction system for all surfaces.

The TC switch shuts off both the stability and traction systems.

There are two wires going to the e-locker: light green and black (I think these are the colors). +battery is switched to the light green wire and the black wire returns to the transfer case shift control module where it connects to ground through a resistor/current limiter. The final circuit will be pretty simple but you need to do serveral tests first to understand what is inside the control module.

For example, you'll need a diode to clamp the inductive current for the e-locker coil to prevent an insulation breakdown when you interrupt coil current.

[HummBebe]

The TC switch shuts off both the stability and traction systems.



TC Switch?

[ChevyHighPerformance]

Sorry, I wasn't clear - Traction Control System - TCS switch.

[HummBebe]

On which model H2 or H3?

If H3, what switch are you referring to?

[ChevyHighPerformance]

I was refering to the H3. This is the rightmost switch - picture of a car with squiggly lines underneath it. Hold it in for 5 sec and this will disable the traction control and the stability system (if you have it).

[HummBebe]

I was refering to the H3. This is the rightmost switch - picture of a car with squiggly lines underneath it. Hold it in for 5 sec and this will disable the traction control and the stability system (if you have it).

That is the stabilitrac switch. Different system than the traction control.

You cannot turn off the traction control:D

[yzergod]

You cannot turn off the traction control:D

You are incorrect sir/maam (;))... there is a switch on the column... the ignition switch! That will turn off the traction control. But I don't think it's useful over 5 mpg (I could be wrong;) )!

[HummBebe]

Sir????

You = :OWNED::OWNED::OWNED:

[ChevyHighPerformance]

Here are two pages from the owners manual. You can get the electronic owners manual from www.mygmlink.com (http://www.mygmlink.com) after you register.

[fourfourto]

Here are two pages from the owners manual. You can get the electronic owners manual from www.mygmlink.com (http://www.mygmlink.com) after you register.


:popcorn: That sure explains it :clapping:

[DURAMAX TIM]

:popcorn: That sure explains it :clapping:

so lets see, we turn OFF the TC/SC when in mud and snow or it will limit wheel spin which may get u stuck.
Now the e locker kicks out over 20mph, so if play off road in muddy or snowy conditions we just have to keep the speedo under 20mph :twak:

I know I've hit a lot more than 20mph in mud pits and snow drifts not to mention slippery hills.


I still want my elocker to stay on when I turn it on.

[DURAMAX TIM]

***crickets****




now what?

[SR1355]

so lets see, we turn OFF the TC/SC when in mud and snow or it will limit wheel spin which may get u stuck.
Now the e locker kicks out over 20mph, so if play off road in muddy or snowy conditions we just have to keep the speedo under 20mph :twak:

I know I've hit a lot more than 20mph in mud pits and snow drifts not to mention slippery hills.


I still want my elocker to stay on when I turn it on.

:iagree:

[ChevyHighPerformance]

I made the mistake of not getting the off-road package so I can't just try this on mine. How about this. With the key off, disconnect the connector from the e-locker. Measure the resistance from the black wire (going to the control not to the e-lock coil) to a good ground as close to the control as possible. Zero out the probe resistance first.

[Hal]

I have the service manual and pages 4-150, 4-156, 4-160 explain the following respectively: Differential lock schematics, Circuit Description, and Electronic Diff Lock Will Not Disengage troubleshooting. I wish I could post this and have it be readable or be able to explain it. (I'm a Pharmacist not an Electrical Engineer):confused: if anyone else can post this info for ChevyHighPerformance to look at we might have an answer.

[H3PAC]

I'm a Pharmacist not an Electrical Engineer.

Damn it Jim!

32564

[ChevyHighPerformance]

I have the service manual and pages 4-150, 4-156, 4-160 explain the following respectively: Differential lock schematics, Circuit Description, and Electronic Diff Lock Will Not Disengage troubleshooting. I wish I could post this and have it be readable or be able to explain it. (I'm a Pharmacist not an Electrical Engineer):confused: if anyone else can post this info for ChevyHighPerformance to look at we might have an answer.

I have these too. The control monitors the return. My question is it through a relatively large resistance to limit current (like 3 ohms) or a small resistance (like 0.25 ohms) just to monitor the current. My guess is that it's a small resistance, but I'd like to make sure. That's why I asked for a resistance measurement.

[DURAMAX TIM]

I'll do it sunday if someone doesn't get it done before.

[ChevyHighPerformance]

Here is the circuit I?m thinking about to remotely control the e-locker. First, there are many different circuits to do this function. I?m leaning this way because you only need a single wire to run to the remote control switch. When you use the normal stock e-lock switch, the light green wire gets +12 volts and the black wire gets tied to ground. This energizes the relay?s coil. The contacts connect the e-locker coil to the transfer case shift control module.

When the normal stock e-lock switch is selected to disable the e-lock, you can control the e-locker using the remote switch. When the switch is closed, +12 volts is applied and current flows through a 5 amp fuse, a resistor (depends on the black wire to ground resistance measurement), to the e-locker coil, and then to ground.

It?s probably best to not use both the normal stock e-lock switch and the new switch. If both switches are used, you go over 20 MPH, and the transfer case shift control module tries to deenergize the e-locker, the relay will open and your remote switch will supply power to keep the e-locker engaged. The concern is I don?t know what happens to the e-locker while the relay transitions from on to off.

The part numbers listed are Radio Shack part numbers. Do not eliminate the diode.

[wpage]

CHP,
Your concern on this mod regarding using this override circuit and the stock circuit is valid. There is a missing link in your stock illustration that would be the interrupter or sensor that opens this circuit when certain conditions are met.
Implementing this mod would not be advised till after warrentee expiration.

[ChevyHighPerformance]

Here are two pages from the owners manual. You can get the electronic owners manual from www.mygmlink.com (http://www.mygmlink.com) after you register.

It looks like I'm wrong and HummBebe is correct. I switched the stabilitrak system off by holding down the stab button, as the manual states, and I was still able to get the traction control to kick in even though the display showed "stab sys off". This is different from how the owners manual says the system operates.

[HummBebe]

It looks like I'm wrong and HummBebe is correct. I switched the stabilitrak system off by holding down the stab button, as the manual states, and I was still able to get the traction control to kick in even though the display showed "stab sys off". This is different from how the owners manual says the system operates.

Thank you for posting that. :D

[DennisAJC]

The locker is availabe with either transmission and the bypass he's referring to is so that it can be engaged in 4Hi-Lock. From the factory, you can only engage the rear locker when in 4Lo and it automatically disengages if you go over 20mph, IIRC.

There was some talk about this on here before. But I haven't seen anyone post that they have successfully bypassed it in the H3 yet.


The rear locker can be modified to work "anytime". There is a way where you can add a "bypass" wire to trick the CPU that it was in 4-low. It's been done many times with Tacomas and some Heeps. I'll try and take a more deeper look into this.