Can’t get abs light to go away

I pulled my 98’ ext cab tacoma into the shop to get it ready for an inspection. Everything looked good underneath and I thought I was ready to get it inspection once I pull it out the abs light comes on so I clean off all the sensor and the light comes back on. I then pull the codes for it and I get codes 31, 32, 33, 34, 44, and 49. The light only comes on at about 12 mph and goes of everytime the key is turned off I have checked and cleaned every sensor as well as every connector for the abs. I have no idea what could be causing the light to come on. I would also like to know if there is anyway to reset the abs code without a scanner and if the abs codes can be read with a scanner

 

Codes 31, 32, 33, and 34 indicate faults for each wheel speed sensor. 44 is the deceleration sensor and 49 is the brake light circuit. I found that out just by Googling it; a regular OBDII scanner won't scan or reset ABS faults. Have you checked the two ABS fuses?

 

Just putting this out there. You can remove the ABS light bulb from behind the cluster and remove either of the ABS fuses (smaller one is easier) from the fuse box, and you'll:

1) Have disabled your ABS system permanently
2) Never get another ABS warning light again

And to boot, no inspector will notice because scan tools can't read ABS codes on our trucks

 

I checked both fuses and they both are good. I’m not sure if the pump went to the bad and is sending all these codes or if a ground is bad somewhere. I don’t really want to pull the abs out of it at the moment but if it gets to the point where i’m tired of fooling with it I probably will.

 

Replace all sensors. Cleaning them does nothing, unless they've collected a bunch of rust... but then you'll likely have to clean the ABS rings as well.

 

I’m not gonna start throwing sensors at it yet. I find it very unlikely that every sensor went bad. Is there a way to test a censor to see if one isn’t sending a signal to the abs module?

 

The FSM includes a way to test them. The "SST" is basically just a jumper wire.

That being said, you should be able to unplug the sensor and connect a multimeter to it. Spinning the wheel by hand should produce a small amount of AC voltage.

It's very unlikely that all 4 sensors are bad. It's more likely a wiring issue or an issue with the ABS module itself.

 

After following the FSM to test the sensor I got 3 new codes. 73, 74, and 77 which is low voltage from the left and right rear. 77 is abnormal voltage from the right rear sensor. I think i’m to the point where i’m gonna put rear sensors in it and see if that fixes anything.

 

Teflon..... where do you park your taco?

internet guess
4 sensors throw a code at same time points me to direction of critters chewing on wires.....somewhere

 

Before you put new sensors in, try cleaning the harness connections for them. If you follow the wire up from the sensors on the axle they run near the brake line up to the drivers side frame rail. There is a connector there. pull that apart and spray it down with electric safe contact cleaner. Wait for it to dry, and reconnect. I'd do that to each of the sensor wires prior to throwing new ones at it.

 

You'll end up replacing sensors. No need to buy expensive ones, $20/set off ebay will be just fine.

 

Unplug a sensor and check its resistance with a multimeter. A good sensor will have about 900-1200ohms of resistance, as per the Factory Service Manual.

 

This helps me out a lot.
Ever since installing an ultraguage my ABS light flashes (That's fine, I can live with that)... but every once and a while the light isn't flashing (for some reason) but when I slow down to come to a stop, the ABS system pulses rapidly for a second.

 

That's strange, but sounds like a perfectly good reason to delete the system.

 

^^^ this is an indication of a speed sensor. Anything that will affect the magnetic pulses will set it off, rust on the reluctor, too large of a gap by a few thousanths of an inch... wheel bearings may be a contributor to this.

 

indeed. its random and inconsistent

Yeah that was my thoughts too. I took the sensors out and cleaned them. Replaced and still had issues where the ABS light would be out and coming to a stop the ABS would pulse for a second. Pulled the negative off the battery and reset the system. Following that it was back to normal - just a flashing light and no pulsing when stopping. But I did have a random day where the ABS light was off and pulses happened.

Seems like the best bet for me is to pull the fuse so I don't get random days when it freaks out. It can be a surprise if you weren't expecting anything and then at about 2mph the truck shutters.

 

On my 01 Ranger Edge I have the same ABS pulse when the LF tire is low on air and when the road is wet and the front tires contact the limit line paint on the road, it is always the LF that drops out. The ABS is opperating exactly as designed. I hooked up my Solus Edge scanner to view the sine wave pattern from the sensors and the LF has a much lower amplitude, I broke that sensor when I took that strut assembly off for some suspension work and put in an aftermarket sensor. I swapped the RF sensor to the LF and spun the front wheels and compared readings, the crap pattern followed the sensor. Sometimes a fix causes more problems than the original issue.

 

For the life of me I cannot understand why people would spend any significant amount of money or time trying to fix their ABS.

 

While I understand that it's easy to "make the problem go away".. but ABS certainly is not a bad thing, and if it's easily fixed, it should be. If the truck has a whole host of other problems, maybe it's not worth it. However everything still works perfectly on my truck, and when my light popped on, I was able to fix it.