2nd Gen Non-Engine/Transmission ABS light

[Tractorat]

It happened so fast that Im not sure it happened at all. But the other day I sure thought I saw the abs light come on for just a brief second. I slammed my brakes on in a slick spot just to make sure the abs works, and everything is fine.

Should that set a code ? I clicked the key 3 times and nothing is there. If a code is set somewhere, is it something a scan tool would find ?

 

[VolsFan]

My abs light came on briefly when I was leaving a muddy logging road in wv, but after a few miles it went off. Figured the rain cleaned it out

 

[JR]

If you had a malfunction in the abs system the light would stay illuminated. Not sure why it would have flashed, maybe an early sign of a bad connection about to show itself. I wouldn't be concerned unless the light returns

 

[HHhuntitall]

Yeah, it probably was just a failure to read one of the sensors... If it's cold, I've seen them not work at all until they warm up. The light stays on until you drive it some, and then it goes off.... Probably not going to set a code that way. The rear sensors are really bad about getting permeated with water, and then cracking when they freeze... or rusting the magnet away to nothing. The fronts take a hammering on all my stuff from the brush and mud dragging on the wires.... My lights are chronically on in various trucks.....

 

[PSpychalski]

Have continuous problem with my ABS light. Has to do with the Rear sensor connection on top of the rear diff. Not a real good design. Has a tendency in cold weather to break contact and flash or have steady ABS light. Zip-tied together, still loses contact on occasion. Especially on a rough road. Hope this helps.

 

[VolsFan]

I posted above about my lights acting up briefly. Now since I just did all the rotors and pads the abs and brake lights are on constantly. I've bled the brakes, sensors look good. Disconnected batteries to reset the computer. Won't go off. Any ideas where to look? Also, the fluid itself is pretty dark, don't know if it would be worthwhile to change out all the fluid or not if it would possibly turn the lights off. Thanks for any info

 

[PSpychalski]

front sensors. Check for continuity between the pins under the hood. Both sensors should show continuity. Next check the connector on top of the rear diff. Sensor should have continuity. Clean rear sensor connector and reattach. No continuity, bad sensor.

 

[JR]

I posted above about my lights acting up briefly. Now since I just did all the rotors and pads the abs and brake lights are on constantly. I've bled the brakes, sensors look good. Disconnected batteries to reset the computer. Won't go off. Any ideas where to look? Also, the fluid itself is pretty dark, don't know if it would be worthwhile to change out all the fluid or not if it would possibly turn the lights off. Thanks for any info

I think I remember you saying saying you were going to grease the hubs through the abs holes? I have not done that before but I wonder if you got grease on the sensors and it has affected the signals?
As for the brake fluid, it should be flushed every 2 years. Brake fluid is hygroscopic, and water can drastically lower the boiling point of the fluid and corode brake components in severe cases.

 

[VolsFan]

That's correct, I did grease through the abs holes, and I ended up taking both sides back apart to clean the sensors. They are clean now. I checked continuity with the multimeter and all looks good there.i have not done the back sensor, had to leave before I could get to it. Only thing I can figure is pushing the caliper piston back in the bore pushed fouled fluid back up. Thanks for replies

 

[HHhuntitall]

It's good to flush the fluid every few, if it gets dark looking. That means it's got a lot of water absorbed in it. I don't think it will affect your ABS light function, though.

I grease every hub bearing set I install, and I've never had a grease on sensor problem, as long as the sensor is good. In a colder climate than Texas, it might cause a problem, though... not sure. I wouldn't think so. Regardless, you've eliminated it two of the problems...

 

[VolsFan]

I checked the rear sensor and it is fine. I am having an issue with the 4wd light intermittently flashing while in 2wd also. At this point I am thinking the abs and brake light as well as the 4wd light are all related somehow, as they all started at about the same time. Going to check the axle disconnect for vacuum leaks.

 

[PSpychalski]

Your problem may be in the Antilock Brake Controller. it controls Front/Rear Speed sensors and 4WD Sense switch. Check and clean the connector at controller, check the grounds from the controller. Clean and reattach. Hope this narrows down your problem.

 

[VolsFan]

If the antilock brake controller 4wd sense switch, then that does sound like my issue. I will check the connections hopefully tomorrow. Also, I am assuming the Antilock brake controller is at the ABS pump?

 

[PSpychalski]

Don't have schematic in front of me..I believe it is. Can get back with you in a couple of days and give you connector and pin number.

 

[PSpychalski]

Depending where the trouble lies, your ABS may send a trouble code to the ECM. Check for any codes. The ground pins are Connector C1, pins 6 & 13. Rear Wheel Sensor, Connector C1 pins 1(+) & 8(-). L.Front Sensor Connector C2 Pins 1(+) & 2(-). R. Front Sensor Connector C2 Pins 3(-) & 4(+). 4WD Sense Connector C1 Pin 2. Good luck, hope you find the problem.