2nd Gen Non-Engine/Transmission ABS/Brake Light Still Burns

[rholcom2]

By reading some past posts on the speed sensor going bad in the rear end, and thus the ABS and Brake light, illuminates on the dash, I thought that by changing out the speed sensor would fix my problem. I installed a new speed sensor this morning, and to my dissapointment the Brake and ABS lights are still lit in the dash. Am I missing something? Do you have to go into the computer and clear the codes or something? Any suggestions?

 

[rholcom2]

I know someone knows. You guys are gurus!!!

 

[JSykes]

Measure the resistance across the pins on the rear wheel speed sensor with a multimeter. It should measure around 1800 ohms on a brand new one. If it is an open circuit then the sensor is bad. If it is good, you will need to have the codes checked and go from there.



Good Luck,



Jay

 

[RustyJC]

Another thing that will cause the ABS/Brake light to come on is excessive speed differential between the front and rear wheels. If you've done any smoky burnouts lately, spun the rear wheels on ice, etc. , it'll set a code and bring on the light.



Rusty

 

[jarsong]

Originally posted by RustyJC

Another thing that will cause the ABS/Brake light to come on is excessive speed differential between the front and rear wheels. If you've done any smoky burnouts lately, spun the rear wheels on ice, etc. , it'll set a code and bring on the light.



Rusty

I had this happen after doing a couple doughnut in the snow! Went out a short while later...

jarsong

 

[rholcom2]

I will try to get out and check the resistance this afternoon. I wonder if it is in fact bad, if the dealer will accept that something they sold was inferior and replace it with a working unit?? One of those great questions in life!!! Thanks guys for all the help. I dont remember doing any burn-outs. So I am kinda doubting thats what caused this.

 

[Rogue Ram]

I am doing brakes today, and my abs/brake light comes on at start up, along with the "check gauges" light. It appears I am down about 25-30% of my brake fluid, and we are guessing that is the problem. Check your brake fluid level... I may be way off, but then again... .....



RR

 

[RBrunson]

An other thing that others have mentioned is that it requires 50 starts of the engine before the light will reset. I thought mine would never go off, but it eventually did.

 

[Steve St.Laurent]

Those lights will come on if there is no power to that bus as well. Try checking your fuses and make sure there isn't one blown. There are several different power buses on the ignition switch - all fused - one of those is just for the brake system. When I first installed the turbo temp monitor on my truck I only powered up one of them and the engine would stay running but the abs and brake lights would come on.



Rogue Ram - check your pads and shoes. I'm betting that one of them is very worn - that should be the only way you see a loss of brake fluid. Some cars/trucks (maybe yours - I don't know) have sensors in the fluid reservoirs and the reservoirs are sized such that when your pads are worn out the fluid gets low enough to trigger the sensor and turn on a light. Brake fluid doesn't just "disappear".

 

[Rogue Ram]

DING DING DING, we have a winner..

and Steve gets the prize!!! Two things:



**Yep, you were right Steve. Leaky right rear wheel cylinder. Not bad, but enough. Swapped out for the one ton cylinders, and top of the line United shoes. Near disaster. All done, adjusted, wheels on, started to test drive, fluid all over by left rear! Tore it down... ... ... . new cylinder had the forward piston get accidentally depressed or something and it was enough so the fluid made a big mess. Hit it all with brak-kleen, wiped up, shoes looked fine, not enough time nor mess to damage them, and it all works fine.



**The ABS/Brake warning light stayed on. Hmmmmm... . so, on top of that "proprotioning valve" (???) in front of the master cylinder, there is a black button with an orange tag on it--no lable tho. Uncle and I looked at each other, he said that somehow a valve or pin needed to be reset to make something or other equal... ... . he pushed this button couple of times, I started truck, no warning light! Maybe it does nothing, or maybe it took time for the fluid to do something or other, but lights did go out.



They do come on when key is turned to start, but go off when truck starts. I KNOW I have a burnt out fuse that controlled the trailer brake lights... ... I will replace and report back.



Thanks!!!



!!

 

[rholcom2]

Its goign on two weeks, and my lights still havnt reset and went off. Lets hope it happens soon!!!!

 

[Rogue Ram]

rholcom2,



I think there's a TSB or something for the proportioning valve (Steve, am I calling this thing correctly?) or the master cylinder----hit the TSB button at the top of this screen, and look through it.



Are the lights lit up constantly??? Depress that button I spoke of earlier, maybe that will do it?



RR

 

[fishjack1]

My truck is a 1996 4x4 and I had a vacuum leak that caused the ABS and brake lights to stay on. Not sure about your 1998 but my leak was at the 4x4 vacuum engagement mechanism on the front axle.



May be worth checking on your truck.

 

[rholcom2]

UPDATE***



1) I checked resistance across the rear speed sensor. It is at approximately 1800 (sorry, dont know where the decimal is supposed to be).



2) I also checked the fuse pannel. All fuses are good and not blown.



3) Then went down to the axel. Everything looks to be good there. I unhooked everything, and then plugged it back in, used some contact cleaner on the electrical connections.



4) Then I went back to the brake fluid resavour, and there is plenty of brake fluid in it.



I believe these observations suggest I need to replace the ABS sensor on the front axel.



I believe before I do that (I have been told) I will stop by Auto Zone and have them hook their scan tool up and see if there are any codes. Mabye that will give me some specific thing to try.



Thanks for all your help, if anyone has anything further I will check this tomorrow morning.