Rear Diff Lock Anytime Mod 3rd Gen DEVELOPMENT

@Up2NoGood, by putting in some assistance, you inspired me to take a look at this again and see if I can motivate myself to build a prototype.

I hate having to buy pre-terminated pins for the Toyota connectors. Any chance you can give a hand at matching up the 10 pin connector (and mate) to a TE (or somebody else) P/N?

(Hoping your google/digikey FU is better than mine). I think I can buy both halves of this 10 pin from Toyota, but not my preference, if that is the only solution...

 

Yeah I can have a look when I get a chance. I know exactly what you mean about buying the pre-terminated pins... pretty much highway robbery through Toyota. Here is the updated part numbers to include the TE terminals for the 40 pin connector:

Toyota 90980-12557
Likely converts over to TE 1318389-1
Mating male connector TE 1318384-2
Pin Terminal TE 1123343-1
Pin Terninal TE 1123343-2 (gold plated terminals)

I do have some of the 1123343-1 terminals if you need I could mail some over to you. Otherwise they should be readily available on digikey and mouser and pretty cheap too, especially compared to the Toyota pre-crimp which would be 82998-12870.

 

I've been following this thread from the beginning and really hope ya'll can make something work here. Wish I could be of assistance, but at this stage, its way above my pay grade. If I can pitch in with testing at some point, I will be sure to chime in.

 

Discussed connectors in Manual Transmission Thread.
Working on combining schematics of diff anytime and 2wheel low

still want help on the 10 pin connector
@DaveInDenver had the following suggestion

 

I was just doing some digging on @Up2NoGood's suggestions (which are excellent BTW).

Checking on 90980-12557, which is listed as 0.64 III series and Toyota recommends 82998-12870 for the 160mm pigtail repair. In my experience this terminal crosses best to a TE terminal p/n 1674311-2.

ETA: This part seems to be low in stock so perhaps has been superseded with those Jaimes has.

Which would mean that perhaps the 40 pin connector could alternatively be some other TE parts in the TH025 series.

1674312-1 (white)
1674312-2 (black)
1379671-4 (green, but minimum buy on this one is 4,000)

As for a male mating connector and terminal. I've run into cases where the only mate is a PCB-mount, no bulkhead or free hanging option is even made. I don't know that this is true here but it wouldn't surprise me either.

 

for the 40 pin, I think pcb-mount will be the only mate that will be cheaply available. Digikey has the 40 pin TE connectors and pins that @Up2NoGood referenced, so I think I have some kind of solution for those. May not be ideal, but workable.

But can't figure out 10 pin connectors yet (besides excessive Toyota costs)

Thanks for input

 

Keep up. The good work fellas! My knowledge on this matter is worthless to you guys. So I'm in the stands rooting for you both!

 

The 10 pin that Toyota calls 90980-10997 uses 82998-12340 pigtail.

This is the cross data I have compiled at this point.



I don't have TE crosses for the terminals, at least ones that are stocked anywhere. I believe they'd fall somewhere in the Multilock series.
http://www.te.com/usa-en/product-CAT-M9194-T273.html?q=&n=127963&d=103205&type=products


The housing/connector, I dunno, this one resembles it but appears to differ in some details.

TE part 936092:
http://www.te.com/commerce/Document...6092&DocType=Customer+Drawing&DocLang=English

This mates to 936129:
http://www.te.com/commerce/Document...6129&DocType=Customer+Drawing&DocLang=English

 

Some of the guys on this forum are absolutely brilliant. Thanks for all your hard work.

 

Thanks for working on this. Even buying the Toyota housings for the 10 pin wouldn't be insane... just hate those pre-terminated expensive repair pins to go in them... especially because have to splice them again in general.

 

My main two hurdles historically in finding individual parts is (1) I don't read & speak Japanese and (b) am not located in Japan. I've also run into internal T.E. part numbers that match Sumitomo & Yazaki, so they may be a middleman sourcing them for Toyota NA.

Also getting them individually is sometimes impossible, which makes sense if there's a custom configuration or pin count that Toyota needs the OEM makes them in runs of tens of thousands for them but wouldn't want to deal with selling 2 here, 5 there over the next 10 years through regular distribution when they already have existing regular catalog lines with similar features.

Point being, for a handful it's usually worth just buying connectors/housing from Toyota. Then you know the geometry is correct, so it fits, seals and/or locks like it should. Like you say, though, the repair pigtails are ridiculous when you can buy a spool of wire and a bag of seals and terminals for what just one cost.

 

Thanks for your help. I agree on the housings. Just dont want to speed so much money for some pins and wires that are too short to me do much good.

 

I sat down with the service manager at my local dealer ship and he gave my a screen shot of the wiring diagram of the rear diff. There's only a power and ground going to the diff locker.

I haven't read through all 7 pages of this thread but unless I'm over simplifying this, why not just run a power and ground to the rear locker and bypass the 4wd module. Doing that you will be able to even keep the stock switch and run new power and ground to it.

 

@BigWhiteTRD If you need a guinea pig for testing, I would be more than willing to foot the parts bill and provide testing / feedback. From a mechanical side, I can provide assistance, although building low voltage circuits is not my expertise. Anyhow, I typically only use my truck on the weekends, so if we do manage to goof something up, it isn't the end of the world. Let me know if you need some assistance!

 

Has it changed a lot then? There are 5 wires that go to the locker in my 2008, but I know the 3rd gen is different. Two are the motor, one is ground, two for the limit switches. It can be made to function anytime, that's not a problem.

https://www.tacomaworld.com/threads/locker-anytime-mod-for-dummies-2005.353724/

The point of this thread I though is to implement this but without cutting and splicing your stock harness to do it. Rather use a plug-n-play harness that fits between the 4WD computer and the rest of the truck. That way it would be reversible, too.

 

Totally different from previous gens.
Now uses an electromagnetic puck, instead of an actual motor to drive diff to locked position.
ECU now feeds the diff a PWM reduced voltage. One voltage for locked, one for unlocked. Dont know what happens if it gets 12V. (burns up or doesnt burn up...?)

 

No real help but I do have actually photos of the 8.75” TRD (Harrop/Eaton) elocker if any one wants to have a look. 4.30:1 ratio out of 6MT 2016 OR for reference. These are shots of mine that was swapped out under warranty for the howling issue.







You can see the coil anti rotation tabs on the outside of the carrier caps and the wiring harness connecting to the coil. The press formed sheet metal ring is there to actuate the switch that turns the indicator lamp on. These lockers are spring loaded to be a normally open differentials. When locked the ring is moved toward the center of the carrier pulling the plunger for the indicator switch. This closes the circuit and lets the 4wd ecm know to turn on the light on the dash. These production units do not seem to be built as robust as the aftermarket units most likely to reduce cost.

I figure a person could order a harness for a Harrop Elocker and wire it in in parallel to the factory wiring with an additional switch to stop the power from back feeding into the factory wiring and achieve the results most of us are seeking.

Due to the duty cycle on the coil you will however have to be careful if you engage the rear locker. I believe it was said earlier that the coil in this locker has a 70% duty cycle or 7 minutes out of 10. That said you could potentially damage the locker if left engaged for more than that 7 minutes. We may be able to find a higher duty cycle coil to retrofit into our lockers to alleviate this issue.

 

I haven't physically looked at the harness but according to the wire diagram it's two wires, one positive and one ground.

As for the point of the thread, why would it be advantageous to not splice into the existing harness? I think it would be simple and an easy solution.

 

Based on what Ted & Red have mentioned it probably is just two wires for a magnetic locking mechanism, but it may be more than just energize to lock, energize to unlock. The 4WD ECU appears to be holding the relay locked with a PWM to keep it from getting too hot. I'm only getting up to speed, too. In the old lockers (like mine) there is a motor and limit switches, which let you use a relay and switch to do this. In the new trucks there's a momentary switch that tells the ECU to do a lock routine, which means replicating it will take either interfacing with the truck's firmware or writing your own (or at least building a PWM circuit to do it).

The harness will allow inserting their own box to interrupt the communication and get the 4WD to do stuff thinking it's doing other stuff, thereby allowing lockers anytime, 2WD low perhaps, without tripping error codes and still doing the other stuff the truck does, like disable ABS in 4WD low.

If it was just a matter of splicing two wires it might be OK, but I think they need access to other signals, the CANbus probably, there's maybe position sensors independent of the two wires for the locker itself as well. So it's easier to just put a harness in-between two existing connectors. Plus it's easy to remove, low risk of damage or worry if harness wire colors change.

 

Maybe I'm oversimplifying it but one sure way to see exactly what you need to do is put a multimeter on the 4wd ECU side of the harness to the locker and engage the locker. Give it some time (maybe 10 minutes) and see what the signal does. Does it modulate the voltage or stay the same... Does it pulse?... Etc.

I think it will be just a constant voltage to the locker. Since it's a magnetic type assembly in the locker then it will be a simple electronic lock and once electricity is no longer there the spring mechanism will unlock the diff.

If I'm right I think that you can either cut the two wires from the 4wd ecu and splice those into power/ground through the factory switch or run your own harness and switch to the factory locker.

This may not be a simple "gray wire mod" but I definitely don't think it's any more difficult than treating it like it's an aftermarket locker you just installed and running your own power/ground wire.

Edit: I also don't think you'll get any dash lights since the 4wd ecu will never even know the locker is engaged or disengaged for that matter.

Keep in mind that if you trick the ECU into letting you engage the locker then you may run into issues getting into 4lo without disengaging the locker. Depending on how the logic circuit in the ECU works... It may be better to just eliminate the whole locker from the ECU.