bigtrucknwheels

Hello all,

Recently, I swapped in a new rear end into my 4Runner, and not being a fan of ABS, I simply disconnected the rear speed sensors and pulled the wire off the 60A fuse link in the engine bay.

Everything was fine and well, I had put on about 230 miles after the swap and subsequent ABS delete, when my speedo was reading zero and my odometer wasn't moving while I was driving. As soon as I came to a stop and started off again, it worked fine. Just today it stopped working for 25 miles or so and then came back on again.

Through the 2 hours I spent reading about speedo issues here at yotatech (love the search LOL), I have discovered that the ECM gets its speed not only from the tranny VSS but the ABS speed sensors as well. So its not very hard for me to connect the dots and figure out this issue is directly related to having no rear speed sensors.

So, my question becomes if I tear out the ABS ECU, will this stop my ECM from becoming confused (consequently causing the speedo to work intermittently), or will this cause me to have no speedo at all? I hate to ask, but the only people on here that I saw that did an ABS delete were 01-02, with VSC and all that other crap as well (not so relevant with my truck lol).

Thanks!

brian2sun

I suggest reconnecting your speed sensors and just leave the ABS fuse out.That's how my '97 is and everything is fine (I just have the ABS dash light on). The earlier ABS systems in our 4runners are CRAP and IMO can be very dangerous on anything but dry pavement. It literally almost killed me before.

bigtrucknwheels

that my friend, is exactly why mine is disconnected. Except ice, I know I could stop faster in my 90 Xtra Cab pickup (weighed more and had smaller brakes LOL).

Unfortunately though, the wires on the donor rear end are hacked, and I don't wanna go through the trouble of connecting it all back up again. I have a hunch that since the VSS goes directly to the ECM, that disconnecting the ABS ECU will circumvent this problem. This will also eliminate the ABS light on the dash, which I am very cool with I will test it as soon as the vehicle is back in my possession, as right now my mother borrowed it for an out of town trip lol.

brian2sun

That makes sense and I don't see any harm in trying it.

bigtrucknwheels

UPDATE

Disconnecting the ABS computer did the exact opposite of what I had hoped, in that it completely disabled the speedo. Reconnecting it returned it to normal functionality.

Next on my test list: temporarily disconnecting the front speed sensors and seeing if I get a speedo reading. My prediction however, is a CEL perhaps, and I don't really expect it to work, but its worth a try

after that, I am gonna look up some wiring diagrams and modify some circuits to make it all work lol

pattycakes77

iTrader: (2)

I know it doesn't help your problem but I agree with Brian2sun, I had some close calls with ABS engaging dangerously in my '98, and one ice fender bender due to the ABS going crazy and not letting ME be in control. I yanked the ABS fuse in the engine bay and I've never looked back. BEST "mod" I've done on my 4runner.

Gerdo

Is the ABS fuse bolted in? How do you get it out? I was thinking of unplugging to plugs from the ABS under the hood.

bigtrucknwheels

Remove the three bolts holding the fuse block in the engine bay (You don't have to unbolt the fuse block, but it makes it so much easier to unhook the ABS). Next, pull off the cover and note the large 60A fuse link right next to the 100A fuse link for the alternator in the lower left hand corner.

You should be able to turn the fuse box in such a way that you can see a little 8mm nut bolting a lead onto the terminal of the 60A fuse link. Simply remove the nut, slide off the wire, tape the end of the wire to prevent accidental contact with other live parts, and reassemble. ABS disabled



Anyways, after unplugging the ABS box and reconnecting it, my speedo hasn't stopped working yet, and I've put on almost 200 miles since then. Interesting lol... I am crossing my fingers that it keeps working, I think it will honestly. Next project is ripping the cluster out and pulling the ABS bulb. I am waiting until I am ready to do an LED upgrade in the cluster though, so I can kill two birds with one stone.

FYI, unplugging the ABS box does not take away the ABS light on the instrument cluster. For this very reason, as long as my speedo keeps working, I will leave the ABS computer connected to avoid having to design a custom wiring setup to make it all work.

bigtrucknwheels

I agree, I hated the ABS from day one on this thing. I downright know I could have stopped faster every time it has kicked in lol. There is nothing safer about it really, except for maybe in some random extreme case somehow or another.

80yota4x4

I recently did a SAS on my 98 4runner and I have this same issue with the speedo not working because of the abs. Is there anyway you can tap into the speed sensor on the transfer case and send the pulse info to the abs speed sensor wires? Trying to fool the abs brain into thinking it is seeing the wheels spinning? My check engine light came on and It sounds like the speedo/abs not working may be my problem. I removed abs on the front obviously and also removed the sensors from the rear when I installed the tacoma rearend. I need to figure this out.

bigtrucknwheels

oh man, thats a good question. I know the impedance of the abs sensors on the front wheels are like 1.2-1.6k and the rear somewhere near that range (slipping my mind right now). If the system is purely signal generation and requires no specific current for the inputs, I think you could use the VSS into the ABS, but I really don't know without having specific information on just how the ABS computer thinks. Maybe a Taco non-ABS computer would fix the issue? Not really sure on the cross compatibility....

I also wanted to update that I have confirmed the ABS comp gets confused. Today I tried an experiment as the roads were wet here, so I stomped on the brakes. As expected, the speedo shot to zero but didn't continue to operate once I left off the brakes (I was still rolling). Once I came to a complete stop, it didn't start working again until I was going about 10 MPH, when the needle suddenly jumped up to speed (it has done that before when the speedo stopped working) and has been working without issue ever since.

80yota4x4

Well I did a little experimenting the other evening and found out that hooking the ABS speed sensor wires to the vss is a no go. My speedo is completely dead and nothing I tried would get it to move. I tried hooking up all four corner abs sensor wires and I tried just the front two since you said you only had the front sensors and it works intermittently. I have searched everywhere I can think for wiring diagrams but all I find is for the 2001 and 2002 with the vsc atrac or whatever bs they had. I am to the point of taking my dash apart and tracing out all the wires for the abs brain to see if I can tell where they integrate with the ecu. The sticker on my ECU reads 5VZ FE 4x4 automatic. It says nothing about abs and I know some of these things came without abs so there should be a way to rewire to get my speedo and ECU happy again.

Have you ever heard of this site? It is ran by Toyota itself and says that have any and all manuals and diagrams for any toyota 1990 and later. I am thinking of joining just to get the diagrams I need for my truck.
https://techinfo.toyota.com/techInfo....toyota.com%2F

80yota4x4

Found this the other day and it worked for my 98 sr5 4x4 3.4 auto with abs.
http://www.hunt4steve.com/99RunLtdDT.html#speed
http://www.hunt4steve.com/OR/99_4Run...Code_P0500.jpg

914runner

Are you sure your 4Runner has a VSS on the tranny? Mine does not, the ABS sensors are the only speed sensors on my rig.

I'm pretty sure you could put a VSS on the tranny and wire it up to the speedo. You may need a signal converter like the Dakota Digital. Then just completely remove all the ABS crap.

bigtrucknwheels

yours must be the odd one out, from what I've gathered every one of them had a VSS except the Limiteds at least until the face lift...

bigtrucknwheels

I bet you're right on this part.

UPDATE:

I hit a bump the other day, not really hard, and the speedo dropped out. I pulled over immediately and came to a stop, didn't shut off the motor or anything, and started driving again, the speedo resumed operation... ...weird lol

80yota4x4

You are correct. However, there is a sensor on the drivers side of my A340F auto trans but I believe I read somewhere that the sensor is only used for the activation/restriction of the ADD front diff system at certain speeds. I didn't know that until I did tons of research. My truck doesn't have the 4 pulse speed sensor I need to bypass the ABS. The ABS brain converts the magnetic frequency over to the 4 pulse wave needed for the speedo to work. The abs sensors are the speed sensors on my truck. The link I listed is how I got my speedo to work and my CEL to go off.

80yota4x4

The 4cylinder base models from what I read had a vss even with abs. The SR5 and higher v6 trucks with abs didn't have a vss only that sensor for the ADD diff and ofcourse the abs speed sensors at each wheel.

I by far am no expert here. All I know is there seems to be no rhyme or reason as to how toyota wired their trucks. You would think they would have standardized it for simplicity sake.

bigtrucknwheels

I agree completely lol

Mrbikerman

I just got finished deleting my abs and retrofitting a vss from a lower model tacoma. I searched all the parts lots around c.springs and NONE of the trucks I saw (all 96-02 4runners and 96-04 tacos) had a vss on the transfercase output shaft. I had to call around, and central foreign didnt even have one. Luckily I got a hold of YodaJim in Denver and he had the sensor and wiring harness, all for 60 bucks.

I started wiring everything up before I knew exactly which wire to splice the sender wire into, so I ended up doing a lot of searching online tonight. I had to pay for an online EWD database to get the pin locations on my 2000 sr5 manual 4runner. Main point, the wire you splice the vss sender into is also grey/light blue (GR-L) and #1 on the c28 connector (which is the small blue connector on the back of the combination meter) for this model/year truck. The wiring diagrams on certain websites about this issue are basically useless without the connector list/key.