E-locker and ABS light clarification

Hello All. I am new here and have done searches both here and other sites on the topic of the factory e-locker and the ABS system. How they interact. I risk posting a dumb question here but I am a bit confused.

Background: We have 99 SR5 Auto w/ TRD Off-road package. Have successfully used the locker, but it has been a while. In fact we had replaced the whole assembly several years ago (my bad due to cracking the cast aluminum trying to get it removed for diagnosis and plenty of dissimilar metal issues, axle housing to locker housing). Turned out there was a wire broken in the cable from the gas tank to the axle. Long time passes and at some point ABS light flashes. Ignored it but then changed to solid. I grew up driving before ABS so it didn't bother me too much, and we were driving another vehicle mostly. Forward at least a year of little use. Drive up to a remote property where in winter the locker is often a necessity to exit the property. Snow falling and collecting quickly. As expected, had issue in this tough spot. Already in 4low, hit the rear locker button, flashing light as normal. Move forward turning a bit, nothing. Back up a bit, still nothing. Repeat a couple of times, same thing. Long story short I eventually made it out (barely). Past the tough spot I tried engaging the locker again on straight and curves in the mountain road. Light load, no load, coast, at stop, didn't ever lock. My guess was that my repaired wire or another on in the same place broke. Stalled diagnosis due to weather and no garage.

Forward to a week or so ago and snow is melting back to gravel. Sunny and decided to open back up the harness where the patch was. I used Good tape and struggled getting it removed. Wiring looked good and no breaks that I could see. But one piece of tape still holding on so in effort to remove it I broke my repair. Patched in a repair wire and go to test. Curved driveway with packed snow and ice, 4wd low, locker button on, light flashing, no engagement sound. Backing up turning to align things, still no lock.

More online searching and ran across something (which I haven't been able to relocate that link) that mentioned if the ABS system has an error the e-locker won't engage. This morning I read a thread that the OP in Canada had no front ABS sensors and he was able to get his locker functioning.

I have ABS codes 32, 44, and 51. Have worked unsuccessfully to address the 51 (pump stuck or bad ABS controller ground). But now I am trying to understand if the ABS system impacts the locker function or not? The ABS system is disabled with the rear locker button engaged, so does it matter if I have ABS codes or not? I guess asking if I need to try solving the 3 ABS error codes before I can expect the locker to work?

Thank you for being kind to a confused newbie.

 

I can only say looking at The EWD for 2000 the ABS System talks with the 4WD Computer if when the ABS system has failed and trips codes I have no idea if that communication is possible. Which maybe keep the locker from engaging .

Since I never had ABS that ever worked I never got down and dirty with the system

If not used things do tend to seize up as well.

 

Thank you for the quick reply. After the rain stopped, my wife and I went out for more diagnosis work. Listening as she turned key on (did not start), shifted to 4wd low with transmission in neutral, then pressed the rear locker button. Diff lock light flashes and I heard sound. Well at least it seemed to be trying, but light kept flashing. She pressed again, noise again and light went off. Repeat again with same response. We jacked up the rear and put on jack stands. Turned wheels wheels turned opposite directions freely. Had her press the button and both wheels turned a very short distance the same direction but even with transmission in neutral it stopped. The locker status light was still flashing. Press button to disengage, hear sound, wheels turn freely in opposite directions again, locker light goes off. Locked it again, worked again. Time for a short test drive. Driveway had a section of slushy, melting ice and was able to turn sharp. Look at tire tracks to see inside tire had slipped disturbing the soft snow.

So I seems the locker really is working, but the "locked" status light doesn't quit flashing. Is it possible the locker is not fully engaging and that is why the light keeps flashing?

 

It could be anything in the complete E Locker switch circuit that is not working So the 4WD ECU thinks the Locker is not locked.

Something grounding back through The E-Locker light causing it to flash

 

More checking at the connectors to the locker, the harness to the small one for the indicator light didn't seem to flex like both wires were there. The connector didn't seem like it locked back into place either so maybe a couple issues there to address. It was getting close to dark with clouds approaching so we called it for today. I hope to be back at it again tomorrow, weather permitting. Thank you again for the help. More to come.

 

Is it possible that maybe your locker is not actually locked, but you may have been shifting in and out of 4wd? When in 4wd with the front wheels on the ground the rears won’t really want to turn either even if they’re off the ground. I don’t think the ABS system will keep the locker from engaging as I had an abs sensor wire break and was still able to use the locker. My abs light was on constantly. I believe but am not certain that the only interaction between the abs and the 4wd computer is used to turn abs off when the locker is engaged

 

Well, owning the Tacoma since new and me reading manuals though forgetting too much, all of our testing has been in 4wd low. I have not done the gray wire mod yet, although have thought of doing it numerous times. So each test has been with the transfer case shifted to 4 low. I see your point in the front tires being on the ground. That would explain why the rear wheels would only move a very short distance of a couple inches with the locker button turned on. My mind was thinking the transmission was in neutral, but the transfer case is after still linking the front and rear wheels together.

 

Update! I did some more investigating at the switch connector on the locker. I started thinking I had a broken wire right at the end of the harness so removed all the tape and plastic clips. I am sure everyone who has worked in that space knows, it is TIGHT quarters. Getting in a good position with the truck on the ground is not an easy task. The wires appeared to be in good shape, just more flex in them than I had expected. Closer look at the connector now that it was freed to move easier. I didn't initially see much issue, except the terminals were different colors. One looked copper and the other black. Looking closer at the connector, it appeared something was stuck in one side. I ended up finding one pin had broken from the switch and was just held in the mating side in the connector. Used a bent paperclip to test the wiring. Key on, the locker light was on solid. Pull my paperclip jumper, light is off. Yay! The wiring was okay. Disassembled the connector and removed the terminals. I used a brass brush to clean as much corrosion off the terminals as possible. Coat the terminals and sealing boots with dielectric grease (yes I know it isn't to help conduct electricity, but does a nice job of lubricating and keeping moisture out) then re-assembling the connector. I cleaned around the switch and attempted to remove it. I was very happy is actually came loose. I was afraid it would be rusted in place. Time to see if I could locate a switch. The local dealer had one in stock, so his assessment is it must be a common part with it being in stock and a 20+ year old truck. Yesterday I ordered the parts and picked them up. I removed the old switch. I will just say that I am happy to have removed the switch, broken terminal or not. It turns out the sealing washer that comes with the kit was cracked through and rusted almost totally through in one place and over half was through in another. The inside of the switch connector had water in it at some point at the one terminal was green from corrosion and the other thinner and brittle. So if someone lives in an area where road salt is used, I would recommend pulling out this switch to inspect the washer and keep water from entering the locker and differential. Anyway, new switch installed, connector attached, and time to test. Barely had to put the transmission in gear and the light changed from flashing to solid. Pressed the locker button again, put transmission in neutral, light goes out!

In conclusion, the ABS system having error codes does not stop the locker from functioning. If the light just continues to flash, I would listen for the locker to engage, then check the switch and the wiring. In this case, the switch had gotten water in the connector and allowed a terminal to break off. New switch and the locker with status light is working as it should. I will be engaging my locker more often to ensure it continues to be able to work well when needed. Last task on this project, reassemble the harness and its strain relief points. I hope this helps someone else with a continually flashing locker light. Thanks to all for their suggestions on how the system works and where to test next. In case someone else needs it, the part number for the replacement switch is #84222-12010.