***Pictures are in order by step at the end of this post***
For those of you who have a Toyota Tacoma 4x4 with the locking rear differential locker that came from Toyota, you have probably been asking your self why it only works in 4-wheel drive low. Or maybe you have wondered how you can lock the rear differential in 4-wheel high or even in 2-wheel drive. After many hours of e-mails and research on the internet there is an answer. YES- you can lock the rear differential in any mode of operation with the push of your “RR DIFF LOCK” switch on the dash. Now there have been many different theories on how to go about doing this modification, but I am only going to discuss the easiest way to do it. Now I have done this to my 2001 Tacoma Quad Cab, and I have had no problems with my truck. Below are the steps listed to go about changing your Tacoma.
1) Remove the plastic strip that has four screws in it on the driver’s side.
2) Remove the driver’s side-kick panel. This would be down by your left foot.
3) Locate a little black box (it is about 4 inches square by 1 inch thick); this is the trucks rear diff. lock ECU. Remove the box from the bracket (the bolt takes a 10mm socket).
4) Now there should be a wire harness into this box that has 10 wires into it. You will need to locate the GREY wire in this wire bundle. The GREY wire is located between a GREEN-YELLOW wire and a WHITE-BLACK wire. For those of you reading the wire diagram the GREY wire is the #8 wire on the plug.
5) Now that you have located the GREY wire you need to cut the GREY wire about 3 inches from the connector of the ECU.
6) Connect an 8-inch piece of wire to the GREY wire coming out of the ECU. (This is very important that you do the wire coming out of the ECU and not the wire that goes up into the wire bundle.) Tape off the end of the GREY wire that goes into the wire bundle and leave it alone.
7) You are going to want to GROUND this spliced in wire that you just put on. I connected the wire to the mounting bolt of the ECU, which was the easiest.
8) Reinstall the ECU and your kick panel.
Now that you have completed these steps your rear differential will lock whenever you push the “RR DIFF LOCK” button. Just some help full hints too. The locker will not engage while driving over 5 MPH, but you can disengage it at any speed. There is no known limit to how fast you can drive with it locked. Remember!!! the ABS will not work when you lock the rear differential. I would follow the owner’s manual on how to lock the rear differential if you have any doubts.
