1st gen ABS question

I've read through most of the posts about abs issues and most of the posts end without "closure".

In the posts, it gives info on how to test things and everything i have tested comes back as fine/working.

So, I have 2000 extended cab 4x4 sr5 with trd package. Bought it just last fall/winter and I've been slowly through and addressing issues. Apparently the original owner never even had it in to a toyota dealership after he bought it new. There's even recall/TSB stuff that was never addressed and at this point, it's too late for toyota to do anything about them. This one I'm working on now it the ABS light on constantly. I have made the jumper wire and gotten codes and tested everything that I can but nothing comes back bad...

Codes are as follows...
31-front right wheel speed sensor
32-front left wheel speed sensor
44-deceleration sensor circuit
49-open circuit in stop light switch
51-ABS ECU motor bad or bad ground

Nothing comes back as bad or loose or anything so my next question is "what's the likelihood of it being the ABS ECU?

I know most people just yank the fuse and cover/pull the bulb but I figured I would check it out anyway. But it doesn't look like the fuse was pulled or anything.

 

I was looking at factory manual for my 96…..doesn’t even list code 49(no help there)
But IMO
The 31/32 codes are a result of no signal from another tossed code
That decel sensor (code44) peeks my interest……shows separate sensor (behind radio(96)) and test directions in manual

 

Also (again I got 96 info here)
But if the same….
Code 51 says pump locked up
If ABS light on solid (no Morse code flashes) then ECU at fault



Hopes help man

 

Placement on my 2000 is different. Mine is located under the dash, screwed to the firewall (on a mount that set it at "level" under no load),next to where the clutch pedal connecting rod goes through the firewall.

I read a write up on how to test it but the write up asks for a battery that was like $15, or i could have soldered up a handful of AA batteries to get the correct amps/watts/volts that this diy tester needed. All said and done, it would have cost between 35 and 70 for parts and or tools just to test that.
When testing the wheel speed sensors, did get the proper resistance and when testing the leads, I did get 12v on one of the leads which tells me it's active sensors vs passive (could be the other way around, it's late here). I also tested for continuity/resistance from sensors to ABS module and those all tested good and tested ground points on the wiring and all of those tested good. I did notice that my battery is about 5 years old but still holds a charge and shows no signs of going out yet. One of the forums I had read said to ensure the negative terminal is connected well and grounded to the body well... at some point, someone wedged a paperclip in there and bent it over the top of the battery terminal. Don't know if the battery is wrong or just worn but the cable couldn't tighten down enough without the paperclip. I modified the clamp on the negative cable and was able to get good contact and tight grip on that battery terminal so all is good there.
Brake lights work along with turn signals and hazard lights (had to verify since I was checking anyway).

The voltage going to the sensors tells me that module itself is working in some capacity if not fully, or that it's truly fried because it was supposed to be passive but instead, it's sending current where its not supposed to????

 

well that sucks (about the decel sensor test)
1-what is ball park cost for decel sensor?
2-any chance you could feel pump when brake pedal pressed like on lift or 4 jack stands?
3-in your manual, does it state the same as mine(at very bottom) 'always ON...malfunction in ECU'?

 

Sorry. Got super busy and spaced this conversation. Decel sensor run about 1500 ew from an initial search. I don't feel any bump when pressing the brakes. I have not had it on 4 stands though. I have had the front wheels up when I replaced pads and rotors, and I had the rears up when I cleaned, inspected rears and adjusted parking brake but no bumps detected then. I have not looked in a manual. Not sure if you are referencing a service manual (which I don't have) or my owners manual which I actually do have.

 

As far as "always on", it is constantly on unless I install a jumper wire to get the fault codes which is what I had done to get the 5 codes that I have