1. Welcome to Tacoma World!

    You are currently viewing as a guest! To get full-access, you need to register for a FREE account.

    As a registered member, you’ll be able to:
    • Participate in all Tacoma discussion topics
    • Communicate privately with other Tacoma owners from around the world
    • Post your own photos in our Members Gallery
    • Access all special features of the site

4low-trac

Discussion in 'Technical Chat' started by Isthatahemi, Sep 12, 2009.

  1. Apr 22, 2014 at 1:03 PM
    #601
    David K

    David K Well-Known Member

    Joined:
    Jun 27, 2009
    Member:
    #18969
    Messages:
    9,385
    Gender:
    Male
    San Marcos, Alta California
    Vehicle:
    2010 4WD Off Road DC
    Differential Breather Mod Light Bar: 2 Hella 4000 HID, 1 Cibie Halogen. Bilstein 5100s Ride Rite Air Bags
    Hi Jesse, because I have an Off Road and A-TRAC, I have no need to do this mod. It is for the benefit of all 4WD Tacomas that are not Off Road TRDs. What has been reported in this thread is that the 4Lo light blinks, but there is no buzzer/ beeper when the mod is working in L4 (normally the light is solid and the beeping and blinking means you turned the dial to L4, but forgot to put the tranny in N neutral first)... ie. not engaged.
     
  2. Apr 22, 2014 at 2:18 PM
    #602
    crooks420

    crooks420 Well-Known Member

    Joined:
    Oct 11, 2009
    Member:
    #24135
    Messages:
    70
    Gender:
    Male
    First Name:
    Jesse
    San Gabriel
    Vehicle:
    05 AC Prerunner SR5, 12 DC LB 4x4, 70 FJ40

    Cool, I have followed your post (and ensuing drama) on your thread comparing Atrac to Lockers.... I have the blinking 4Lo light,.... I get confused though with all the modes with and without pressing the VSC button. I thought you might have been able to clear that up. I just forget if the AUTO LSD light should come on with the YWM.... indicating that the LSD is activated F & R, as it lights up in 2WD...

    Anyone?

    Jesse
     
  3. Apr 23, 2014 at 8:26 AM
    #603
    David K

    David K Well-Known Member

    Joined:
    Jun 27, 2009
    Member:
    #18969
    Messages:
    9,385
    Gender:
    Male
    San Marcos, Alta California
    Vehicle:
    2010 4WD Off Road DC
    Differential Breather Mod Light Bar: 2 Hella 4000 HID, 1 Cibie Halogen. Bilstein 5100s Ride Rite Air Bags
    Click on the link in my sig to see the details on the VSC button. Here is a brief summary:

    Since 2012 standard mode in H2 and H4 is TRAC ON (traction control with engine output regulation). Here is what the VSC button does:

    H2:
    *Quick Press = AUTO LSD/ TRAC OFF (traction control without regulation, VSC off to 30 mph)
    **Stop and hold in button for 3+ seconds = VSC OFF (no traction control or VSC)

    H4 (2012+):
    *Quick Press = TRAC OFF (traction control without regulation)
    **Stop and hold in button for 3+ seconds = VSC OFF (no traction control or VSC)

    Press the button again or restart the truck and returns to TRAC ON.

    TRAC (light limited slip) and TRAC OFF (strong limited slip) works on all four tires when in 4WD-HI.

    There is no TRAC or TRAC OFF in LOW RANGE... that is what this mod does.

    [I do not know if in TRAC OFF the VSC goes off in H4 up to 30 mph as it does in H2, as I have a 2010 and there is only the unregulated traction control on it and VSC is on]
     
    Last edited: Apr 23, 2014
  4. May 31, 2014 at 5:56 PM
    #604
    avw4x4

    avw4x4 Well-Known Member

    Joined:
    Oct 20, 2013
    Member:
    #114886
    Messages:
    2,042
    Gender:
    Male
    First Name:
    Andrew
    Rochester, NY
    Vehicle:
    '93 FZJ80
    OME 2.5" lift, cobra cb radio, smashed rocker panels
    Hey guys, I had the yellow wire mod done and working great but I just twin sticked my truck.

    Anyone have a wiring diagram to of where the yellow wire comes from before going into the computer? Also is the computer it goes into the traction control computer? Thanks in advance!
     
  5. May 31, 2014 at 7:26 PM
    #605
    Taco'09

    Taco'09 Well-Known Member

    Joined:
    Dec 31, 2008
    Member:
    #12073
    Messages:
    374
    Gender:
    Male
    ^^Hard copies of the Electrical Wiring Diagram may still be available for earlier models with the 09+ wiring otherwise they have to be printed from Toy's TIS system. Otherwise, I have seen snipits of the page titled Multi Mode 4WD and Rear Differential Lock (4WD) have been printed several times here and there on TW.

    FWIW, I have systematically attempted many of the wiring hacks for L4 several years back and reattempted all them again recently. I have always wanted to get the VSC out as it would make the truck more capable in L4 (by eliminating the lurking VSC) but it always whacks the system when I have tried. I pretty much have given up on this as I suspect it is a programming matter that can't be hacked on our end.

    The yellow wire is a ground loop signal wire. From the point where it is being disconnected or "clipped" the wire continues directly to the 4WD ECU where it connects to Terminal 17 of the F13 Connector.

    On the other end of the disconnect it continues via several internal junctions to the T3 Transfer Indicator Switch (L4 Position). When this switch is engaged it then ground connects to 2 engine grounds.

    Not sure what you mean by "twin sticked" unless it means double-stuck. Ha. Sorry, got to laugh. The price of increased traction is always getting worse stuck. You aught to see the mess you can get into with double lockers....
     
    Last edited: May 31, 2014
  6. May 31, 2014 at 7:42 PM
    #606
    avw4x4

    avw4x4 Well-Known Member

    Joined:
    Oct 20, 2013
    Member:
    #114886
    Messages:
    2,042
    Gender:
    Male
    First Name:
    Andrew
    Rochester, NY
    Vehicle:
    '93 FZJ80
    OME 2.5" lift, cobra cb radio, smashed rocker panels
    No, I put a manual transfer case in so I don't have to fuck around with the electric actuator. It has 2 sticks, high low and 2wd 4wd.

    Where you cut the yellow wire (as shown in post 1) isn't the 4wd ecu though... Is it the traction control ecu? He 4wd ecu is above those, directly above the latch for the glovebox. I'm trying to figure out how that wire terminates, guess I'll have to bust out the multimeter :notsure:
     
  7. Jun 1, 2014 at 10:08 AM
    #607
    Taco'09

    Taco'09 Well-Known Member

    Joined:
    Dec 31, 2008
    Member:
    #12073
    Messages:
    374
    Gender:
    Male
    avw4X4, the Skid Control/Traction Control/ABS Control are part of a single module located inside the engine compartment.

    The pic you referenced is of Junction Box No. 2 and the topmost connector shown is the 22-pin PA connector.

    Terminal 22 of the PA connector connects with the same yellow/black wire to the 4WD ECU at terminal 17 of the F13 connector on the ECU. The F13 is the largest of the two connectors on the 4WD ECU.

    If you probe terminal 17 of the F13 connector on the 4WD ECU you should get continuity with both terminals 21, 22 of the PA connector, if not, the terminals are bridged underneath by a junction so make sure to account whether the yellow wire has been clipped or just disconnected.

    Sorry I don't have an illustration to post.
     
  8. Jun 1, 2014 at 1:22 PM
    #608
    avw4x4

    avw4x4 Well-Known Member

    Joined:
    Oct 20, 2013
    Member:
    #114886
    Messages:
    2,042
    Gender:
    Male
    First Name:
    Andrew
    Rochester, NY
    Vehicle:
    '93 FZJ80
    OME 2.5" lift, cobra cb radio, smashed rocker panels
    No problem, haven't had time to play around with it yet anyways.


    Thanks a bunch for the insight though!
     
  9. Jun 10, 2014 at 6:14 AM
    #609
    BRUIN8124

    BRUIN8124 Well-Known Member

    Joined:
    Jan 31, 2012
    Member:
    #71811
    Messages:
    453
    Gender:
    Male
    First Name:
    Mark
    VACATIONLAND
    Vehicle:
    03 4runner Sport Edition 4WD
    I am thinking of doing this. It sounds awesome and easy!

    Anyone have any problems afterwards?

    I looked behind the glove box and found the second yellow wire down. It has the black stripe. However, it is not thinner than the top one. Is this the correct wire?

    My plug looks different than the one shown in this thread. I have 2 columns of wires in this plug. Is it the second yellow wire down in the left collumn on this plug?

    [​IMG]

    I just want to be 100% sure before I go in there and cut. I have an 09 4x4 dcsb with the V6. No TRD or SR5.

    Thanks everyone!
    :deadhorse:
     
    Last edited: Jun 10, 2014
  10. Jun 10, 2014 at 2:59 PM
    #610
    BRUIN8124

    BRUIN8124 Well-Known Member

    Joined:
    Jan 31, 2012
    Member:
    #71811
    Messages:
    453
    Gender:
    Male
    First Name:
    Mark
    VACATIONLAND
    Vehicle:
    03 4runner Sport Edition 4WD
  11. Jun 10, 2014 at 3:51 PM
    #611
    avw4x4

    avw4x4 Well-Known Member

    Joined:
    Oct 20, 2013
    Member:
    #114886
    Messages:
    2,042
    Gender:
    Male
    First Name:
    Andrew
    Rochester, NY
    Vehicle:
    '93 FZJ80
    OME 2.5" lift, cobra cb radio, smashed rocker panels
    Yeah, second one down.

    Atleast for 2010...

    I also don't have that third yellow wire. Just cut it and see if it works, easy enough to put it back together.
     
  12. Jun 10, 2014 at 4:19 PM
    #612
    BRUIN8124

    BRUIN8124 Well-Known Member

    Joined:
    Jan 31, 2012
    Member:
    #71811
    Messages:
    453
    Gender:
    Male
    First Name:
    Mark
    VACATIONLAND
    Vehicle:
    03 4runner Sport Edition 4WD
  13. Jul 21, 2014 at 7:54 PM
    #613
    Roadtrip

    Roadtrip New Member

    Joined:
    Jul 21, 2014
    Member:
    #134386
    Messages:
    3
    Gender:
    Male
    California
    Vehicle:
    4x4 TRD Sport DCLB
    How does 4lo trac work in sand? Probably won't ever do any serious off-roading or steep hills with uneven terrain where a tire will be in the air spinning. Just want to know if the truck will be much more capable in sand, and if it will better than 4hi with trac in getting unstuck on the beach. Thanks!
     
  14. Jul 21, 2014 at 11:29 PM
    #614
    David K

    David K Well-Known Member

    Joined:
    Jun 27, 2009
    Member:
    #18969
    Messages:
    9,385
    Gender:
    Male
    San Marcos, Alta California
    Vehicle:
    2010 4WD Off Road DC
    Differential Breather Mod Light Bar: 2 Hella 4000 HID, 1 Cibie Halogen. Bilstein 5100s Ride Rite Air Bags
    L4 with the added torque in sand is more likely to bury you as it causes the tires to spin. You don't want to spin in sand, as that just sinks you.

    I find that H4 with traction control without modulation (Trac Off on 2012+) works best, and I only need to deflate extra if I have a heavy load.

    Tire pressure dropped to about 50% of normal for A/T tires is the best way to cross sand. Mud tires and 3 ply sidewall tires need more air removed... to about 10 psi.
     
  15. Jul 22, 2014 at 6:30 PM
    #615
    Roadtrip

    Roadtrip New Member

    Joined:
    Jul 21, 2014
    Member:
    #134386
    Messages:
    3
    Gender:
    Male
    California
    Vehicle:
    4x4 TRD Sport DCLB
    Interesting. Thanks!

    So you prefer H4 with trac over L4 with a-trac in sand?

    If you got stuck would you use a-trac or the locker to help you get out? It would have to be some really deep and chalky sand to get stuck on the beach in a Tacoma with aired-down tires. These trucks are sick.
     
  16. Jul 22, 2014 at 10:22 PM
    #616
    David K

    David K Well-Known Member

    Joined:
    Jun 27, 2009
    Member:
    #18969
    Messages:
    9,385
    Gender:
    Male
    San Marcos, Alta California
    Vehicle:
    2010 4WD Off Road DC
    Differential Breather Mod Light Bar: 2 Hella 4000 HID, 1 Cibie Halogen. Bilstein 5100s Ride Rite Air Bags
    When I had no load in my new 2010 Tacoma and experimented on the beach in Baja with all the traction options... and without deflating the tires:

    On the deep, dry sand (bottomless) I could drive about in H4 (standard mode), which then was TRAC with engine output modulation turned OFF. Since 2012 one needs a quick push of the VSC button ("TRAC OFF MODE"), as TRAC in H4 now has engine modulation, same as it has in H2.

    On my 2005 Tacoma, I would get stuck in this type of sand unless I dropped the tires to 15-20 psi. So, right away I saw a big advantage with TRAC limited slip in the 2010!

    Next, I stopped the truck and pressed and held in the VSC button for VSC OFF MODE (no VSC and no TRAC)... this made my 2010 like my 2005... and in a few feet I was stuck!

    So, before going to the fail-safe method of getting out of sand (deflating the tires), I tried A-TRAC... and low and behold, the Tacoma drove itself out of the stuck!

    I went back to standard TRAC ('TRAC OFF' since 2012), and continued to drive about with a big smile!

    This proved to me that TRAC limited slip works... and enhances the truck over regular open differential 4WD greatly.

    I also found that A-TRAC is a miracle device for going more places than before and getting out of stucks or high centered conditions. With just one tire, even a front tire on the ground, A-TRAC will move you!

    Here's photos of my truck's first time in deep sand in Baja (Jan. 2010):

    [​IMG]

    [​IMG]

    [​IMG]

    These photos were taken by a friend while I was zipping about in H4, and the tires were at 32 psi.

    When I came back to this coast, loaded heavily for camping, I had to drop the tire pressure... the weight was just too much and the sand was very loose (it has a lot of crushed sea shells mixed with it).
     
    Last edited: Jul 22, 2014
  17. Jul 23, 2014 at 8:05 AM
    #617
    Roadtrip

    Roadtrip New Member

    Joined:
    Jul 21, 2014
    Member:
    #134386
    Messages:
    3
    Gender:
    Male
    California
    Vehicle:
    4x4 TRD Sport DCLB
    Good stuff! Thanks
     
  18. Jul 24, 2014 at 2:46 PM
    #618
    Pophh53

    Pophh53 Member

    Joined:
    Jun 21, 2014
    Member:
    #132396
    Messages:
    9
    Gender:
    Male
    First Name:
    Herb
    Mesa,az
    Vehicle:
    2014 dclb 4x4 arb air lockers
    3in bilstein coilovers
    I been lurking on the site thought I'd try yellow wire mod,will it work on my 2014 trd sport 4x4?
     
  19. Aug 29, 2014 at 5:16 PM
    #619
    Pophh53

    Pophh53 Member

    Joined:
    Jun 21, 2014
    Member:
    #132396
    Messages:
    9
    Gender:
    Male
    First Name:
    Herb
    Mesa,az
    Vehicle:
    2014 dclb 4x4 arb air lockers
    3in bilstein coilovers
    was my question not worth anyones time to reply?
     
  20. Aug 29, 2014 at 5:48 PM
    #620
    David K

    David K Well-Known Member

    Joined:
    Jun 27, 2009
    Member:
    #18969
    Messages:
    9,385
    Gender:
    Male
    San Marcos, Alta California
    Vehicle:
    2010 4WD Off Road DC
    Differential Breather Mod Light Bar: 2 Hella 4000 HID, 1 Cibie Halogen. Bilstein 5100s Ride Rite Air Bags
    Sorry the others ignored you, I don't need that mod as I have A-TRAC, but my guess based on all I read here is YES, it still works to give you TRAC in L4. I am not sure if that will be with or without engine modulation, since the change made in 2012??? Maybe both using the VSC switch since it is fooling the truck into thinking it is in high range?
     
To Top