Shane

Ok, I'm baffled on this one. I have two Tacoma e-locker ECUs (89533-35070) that I'm using to run my lockers and have something wierd happening with the indicator lamp. In the unlocked mode the LED is on steady when it should be off, and when in the locked mode the LED flashes. However the lockers operate properly regardless of what the LED says is happening. When I benchtested the ECUs months ago they worked perfectly. Off when unlocked, flashing when the actuator was spooled up but not locked, and steady on when locked.

Here's how they're hooked up, where did I screw up?

Here's the Original schematic without my modifications, don't know where I found it.

BTW, I put the warning message on the modified schematic, just to make sure nobody happens across it and tries to use it by accident.

arjan

First I would say thanks for the nice, clear diagram. I was looking for one of those.

Have you tried disconnecting the wire 1 from the ECU. Then only the switch on the diff is controlling the light/led. That way you can isolate your problem a bit more. I also noticed you took the resistor out of the diagram. Is this because you used a light? The lack of diodes in your diagram would maybe cause the problem although I don't think the light should be on in unlocked even without the diodes.

Good luck, Arjan

Shane

I wish I could remember where I found the schematic, it isn't mine. I'm using a 12v LED for the indicator lamp, so that takes care of the resistor. I've never seen anyone else use diodes there. I'll try disconnecting pin 1 as well as completely disconnecting the ECU to see what happens. I'm gonna sound like I'm answering my own question here but I'm just thinking out loud, not entirely sure of any of this...

Here's how I believe it's supposed to work. The ECU feeds 12v on RLP (pin 1) when open and the switch is supposed to pull it to ground. With the switch open the LED should see 12v on both legs, and with the switch closed RLP is pulled to ground and the LED sees a differential of 12v and lights. With the detection switch open and the actuator in locked mode (as in "locked" but not locked) the ECU should alternate 12v and ground making the lamp flash to show trouble. Does this sound correct?

So here's what I'm thinking is actually happening. In unlocked mode somehow the LED is getting a ground either through the ECU or the switch. In locked mode the ECU believes the actuator hasn't completed the move and alternates 12v/ground causing the lamp to flash, or the switch is not pulling RLP to ground. I have verified that the actuator is completing the move in both directions. Is it possible the switch in the diff is bad?

I guess I'll have to borrow an oscilloscope from work, my DVM is updates too slowly to see what's going on. I won't be able to get back into this part of the wiring until at least next weekend anyways, already buttoned up the dash last night. Here's where I mounted them.

arjan

To test the switch on the diff just use a regular voltmeter in the "beep" mode. When the diff is unlocked it should be open circuit (no beep), and in locked mode the meter should beep. If you don't have the "beep" mode, just use the resistance meter. If it's shorted out, it should read somewhere close to zero. The best mulitmeters for flashing lights and or signals are still the old fashioned needle type. I am still looking for a good one.
You are right about the switch or the ecu pulling the other leg to ground. If the diff would be shorting it out the light would always be on. That's why my gut feeling tells me it's not the diff.
I also just checked the fuzzy scans of the service manual phong has on his site, and the wiring layout for the light is the same as your diagram. The diagram is not the problem. It also shows no diodes.
I guess lets first see what disconnecting pin 1 does, keep us updated.
Arjan

Shane

Ok, either the two-pin switch on the diff is bad or it's not moving far enough. It tests open (no continuance) in both positions. Anyone know what's under the switch, can I take it out without anything like a spring flying out and getting lost?

I also tried engaging the locker with the switch disconnected, which made no difference on the behaviour of the indicator lamp. I then tried shorting the connector and testing, the lamp would not light no matter what.

arjan

It is still weird that the light comes on when not locked. Too bad you're not a little closer to the border. I wouldn't mind digging into that one.
I just put the wiring in for mine. My 4runner came partially prewired, so I just plugged in the ECU and the dash switch. The rest of the wiring a grabbed at the junk yard so it's all close to stock wiring. Now I just have to do the mechanical part. I guess that will happen when my gf goes to Europe, so I can use the jetta.
How hard did you find drilling the holes straight, and the threading?

Shane

I'm an idiot, I just realized what I did. Someone please shoot me. :pat:


Ok, first. The LED is hooked up backwards. The positive leg is going to RLP and the two pin switch.

Second, for some reason I grounded the leg that's labeled as getting 12v ignition.


With these conditions the things I'm seeing all make sense. Hopefully this helps someone else out if they screw up like I did. I'm gonna go crawl under a rock...


The question about the switch is still open. Can it be safely removed for bench testing?

Shane

I setup the housing in a drill press, and after drilling I used the press to keep the tap aligned. Worked perfectly so far on two axles.
http://4-low.com/tech/rear_elocker/IMG_0261.jpg

arjan

You were using the ecu as a feed for 12v to ground. What are the changes of that all happening at the same time! Led reversed and tied to ground. Oh well, I've done worse. I hook up climate computers in greenhouses for a living, and I've had my share of "why the heck did I do that?" episodes :-).
Thanks for the pics on the drill press. That makes sense. My parents have a greenhouse, and we have a drill press there. It's old and not quite straight, but it will do for that.
First I was thinking of mounting the third on the housing. Then find some pipe which fits exactly in the stud hole. Then I needed a drill bit to fit exactly in the piece of pipe.
Then weld the pipe around the bit with a bit drill bit sticking out for drilling the hole.
That's somewhat of a difficult approach to a simple problem, but I was just brainstorming. It might work for the long studs, since the deep holes keep everything square.

Shane

Ya, that's what I get for rushing to finish late at night. Oh well. At least I know why it's acting funky now.


Easiest way to do the locker housing mods is to first notch it so you can bolt it in with the old studs that are still used. Then use a machinist's center finder that just fits in the bolt holes in the third to center-punch the centers, or in a pinch a drill bit that just fits although it won't mark as clearly as a punch. Then assemble your press with the table upside down if possible and make sure it's square, then drill and tap the new holes.

arjan

The good news is that you know what's going on. Should be an easy fix.
I just did a quick posting about my wiring:https://www.yotatech.com/forums/f2/i-prewired-my-97-4runner-e-locker-32410/

Shane

Just bringing this thread up to speed, I also have it running on that other board...


Ok, the indicator lamp thing is sorted out. I was correct in that the "ground" of the LED needs to go to pin 1 on the ECU, and it needs 12v ign on the positive lead. Now they work as they are supposed to.

And now to answer my own question about that switch for whoever might find this in a search, yes it can be removed without disturbing anything. Turns out the actuator was a tooth or two off and wasn't moving the fork completely into the locked position, it's now timed correctly and the switch works properly.

Now for the wierd part. According to every diagram out there pins 6 and 9 on the ECU are for the limit switch, 6 being grounded when free and 9 being grounded when locked. Mine strangely enough are doing the exact opposite of that but they're both working properly, if I switch them around to match what they should be according to the diagrams it drives the actuator to the hard limit.


Well it's all working 100% now. I also was having trouble with one of the ECU's refusing to lock either locker. It would perform an unlock, but simply appeared to not respond when told to do a lock. Turned out the trace coming from pin 9 got broken somehow, it should have continuance to the diode circled here:

Here's the fix.