Hi everyone, I’m currently in the process of trying to get my ABS to function properly in my 1996 Jeep XJ with the 4.0. When I got the Jeep the ABS light constantly stayed on, I scanned for codes and nothing came up. I later removed the light because it was constantly staying illuminated, which is annoying. Even still, over a year later the ABS doesn’t work, a few days ago I had to slam on my brakes while it was wet out and my tires locked up, so the ABS system did nothing. I located an ABS module under the carpet below the rear seat on the drivers side. It has a few connections going to it and I looked up the part number on the top and it Came up with this on google- SWITCH, Accelerator (ABS), SWITCH, Accelerator ABS. G Switch. And the part number is- 56006315. If anyone knows how to maybe test this module it would be greatly appreciated if you could tell me how to in the comments, or any other tips on how to test what is broken on my ABS system. Below is a picture of the module in my Jeep. Thanks so much for any help!!

 

I believe that's just a gravity switch with a weight on a spring that detects a sudden stoppage of the vehicle and fires the airbag squib. It doesn't have anything to do with the ABS system. The ABS triggers are the sensors in the wheel hubs that read tone rings and activate the ABS motor when the wheels stop while the car is still in motion. Use a wire brush or sand blaster and clean the rust off the tone rings on the front wheel axle stubs behind the backing plates. A DRB scan tool can diagnose what's wrong with the system and point to the cause. A wheel sensor fault can sometimes be cured just by cleaning the tone rings.

 

Check the wheel sensors at each wheel for dirt. it could also be a broken sensor, and/or rust which will render the ABS inoperative. And turn the light on. There is a reluctor wheel and sensor at each wheel. They are magentic. The reluctor has "windows" that are read by the sensor as the reluctor spins, and that signal is read by the ABS module to determine vehicle speed for braking. Any obstructions will keep the ABS from working. The module sets a code and turns the ABS light on.

Check the wiring to the sensor as well. I dont know where the connectors are, but if you can get to them, disconnect them and look for any corrosion. As for codes. most ABS need a special scanner to read them.

 

@dave1123 That is actually for the ABS on at least the pre 97 XJs. It does exactly what you say but it tells the ABS system that there is a sudden change in velocity.

After buying a pre OBD2 scan tool to fix my ABS,it turned out to be a 2A fuse in my fuse board which was causing the ABS to not function. Check your fuses first, there is an ABS fuse in the PDC under the bonnet along with a relay and one inside the cab which may also be a 2A in your 96. If it is 2A, it's the only one in there so will be obvious.

You can check each sensor with a multimeter set to low volts AC, just probe each pin in the connector and give the wheel a good spin. Your rear wires are the black and red connectors in your picture which then run through the floor to the back, you'll have to follow your front ones back as I can't remember where they split. If you get a voltage, it doesn't mean that everything is good, the signal could be low or if a tooth is damaged, inconsistent. What it does show though is that the sensor isn't straight up dead.

 

You see, you learn something every day! Thanks boxburn, I was told not to mess with that sensor with the key on because you could pop the airbag. Mine has a white arrow painted on it that says "Forward."

 

If 97+ have an electric operated air bag it may serve a dual purpose but I know my airbag is mechanical, no wires at all.

 

All I can tell you for sure is my ABS system in my 2000 WJ doesn't work at all and the DRB scan says it's the logic portion of the ABS unit itself. That's fine with me because I never liked it anyway. I've driven a lot of my life on ice and snow and never had a problem knowing how to handle a vehicle in nasty situations. Before, when it was working, I used to have problems stopping while going downhill at the proper spot to put a newspaper in a mailbox because even after slipping the trans into neutral and just creeping, the ABS would engage and I'd slide 5 or 6 feet past the box! Since it quit working, I can stop where I want to.

I tried taking the ABS warning light bulb out, but the WJ knows better and illuminates the "brake" warning light instead! So now I have a piece of black electrical tape over the ABS light! My state doesn't require the system to work for inspection.