anti lock light again

[mazdarotary]

Hey guys today while driving the Ram I had the anti lock warning light come on,as well as the brake warning light. I did a search on this forum and tried the disconnect fuse #5 for 10 second thing with the key in the ignition and the door open. It seems to have worked but what does this procedure do?Did I just reset something?Will the light come back on soon?I checked the master cylinder and the level wasn't at the top but it also wasn't really low either. I got under the truck as well but there wasn't anything screaming leak to me,plus it was dripping water due to it raining. What could have caused the light to come on?The brakes didn't feel any different either. They have never felt like the other cars I drive but that is probably due more to the other cars having better components. Thanks in advance.





Chris

 

[Philip]

If it was raining like you said. Pull the plug loose back by RWAL valve and dry it out. Most likely some water set it off.



Check the axle sensor plug also.

 

[tugboatphil]

Chris,



Is it coming on and staying on at start, or does it happen on the road? There are several things that can cause it to light up, but most of them won't keep it on all the time.



I had mine coming on last winter when I would brake for a long time. That turned out to be the rear shoe adjusters weren't tight and the fronts were doing all the braking.



Since I had the rear end rebuilt, just about every time I hit a bridge joint on the interstate, they light up for a second or two. I believe this has something to do with the Anti Lock sensor that is bolted into the differential. I haven't had time to look closely, but have been told to check for a wire break.



Of course theres low fluid, air in the lines... . How is your stopping power? Look closely on the backing plates for fluid from a bad wheel cylinder (when it's dry. )



Good luck, and if your brakes aren't up to par, plan ahead, drive slower, keep your distance farther and most importantly... . keep your eye out for small trees (natures emergency brake!)

 

[mazdarotary]

Phil it just happened while I was driving down the road earlier,and then after I shut it down when I got to my destination it came back on at start up and stayed on. I pulled the fuse,and then started it up again,and the lights were out. I am pretty sure this was not a fix but rather a band aid. I hope I am not looking at a expensive fix. The brakes didn't feel any worse when the light was on. Thanks for the input. More info would be greatly appreciated.



Chris

 

[mazdarotary]

Hey guys a quick update. The light came back on during my drive to work this morning. It didn't come on for a few miles,and it wasn't when I was applying the brakes either. I looked at the master cylinder,and there was no change in the level. Also after work I got underneath it ,and didn't notice any drips or wetness near the backing plates. The barkes still feel fine. Where is this box behing the glove compartment?How many wires are there to it?Which on do I ground to get the code?Do I do all this with the key in the on position?Thanks again.



Chris

 

[Philip]

You shouldn't have to ground any wire to get a code. Turn the ing. switch on and off three times. Leave it on the third time and watch the check engine light. This will give you the codes it has stored. Read the flashes. 12 should be the start test code. 55 is the end code. List the codes it throws inbetweens and we will se if it can be found in the book.



A master cylinder going bad on the back section can throw the light on. The fronts control most of the pedal feel on our trucks. It could be coming on from an inbalance between the two systems.

 

[dpuckett]

If your pedal doesnt fallout form under your feet as you put a goodly amount of pressure on it at a light, stop sign, etc, then I'd venture your MC is ok- or at least not buypassing internally. How long has it been since you flushed the brake system? Crud building up in there can cause problems. I have had trouble with my last 2 trucks with brakes not feeling right. Rears being out of adjustment will make the pedla mushy. If you can push the pedal more than halfway to the floor, you most likely have air in the system, or an internal bypass somewhere. The RWAL valve/ unit can be a booger to bleed.



Daniel

 

[mazdarotary]

Th epedal feels fine. I had the brakes bleed last fall. I did the rear brakes a few months ago. I did not bleed the brakes after I did them though. I think I adjusted them correctly. I adjusted until there was a bit of drag on the drums. Is that the right way?Is this a major problem that I shouldn't being driving the truck?Like I said the pedal feels normal,and I am not losing any fluid that I can see.





Chris

 

[dpuckett]

I always adjust mine to have a goodly amount of drag on the drum- like all the way around, and have to give ita single arm effort to get it rolling.



If you have a good feeling pedal, arent losing any fluid, and are happy with the braking, drive it. The RWAL is a funny animal in these trucks, anyway. If in doubt, pull the plug behind the glove box.



-DP

 

[Paychk]

The key on 3 times provides the engine trouble codes only, by counting the flashes of the check engine light. For the RWAL codes you must ground a black wire that is usually located behind the glove box, near the 14 pin connector that hooks to the RWAL module. The flashes will be displayed on the amber anti-lock brake warning light.



The flashes will start with a long flash followed by shorter flashes, the long flash must be counted along with the short ones. The RWAL can only store and display 1 code at a time. To clear the codes disconnect the 14 pin plug at the RWAL module for 5 seconds. There are 2 types of control modules, the second type clears codes 9 & 11 when the key is turned off, to make it easy on yourself always check for codes with the engine running.



The brake & anti-lock warning lamps will light if the vacuum falls below a set level. Check the vacuum lines and sensor, located near drivers side hood hinge, it will have a line and 3 wires coming out of it.

 

[arrowsmith]

I have had two boosters go bad The light will take a little longer to go out when starting the motor. When stoped if I mashed hard on the peddle for several seconds it would light both lamps

Arrowsmith

 

[1stgen4evr]

Antilock light

I have found the light and the antilock system to be unreliable and useless to the point that I no longer have mine connected. After a long and exhaustive effort to put the light out on one of my trucks, I finally gave up and unhooked the system. That puts the light out.



IMHO if a driver doesn't know enough about brake function to drive without an antilock system, perhaps he/she should not be under the wheel.



There are a number of posts on the subject of antilock happening at extremely inappropriate times. National studies have shown that they are not effective at reducing accidents and may in fact contrubute to MORE accidents.



1stgen4evr

James

 

[dpuckett]

National studies have shown that they are not effective at reducing accidents and may in fact contrubute to MORE accidents.

Exactly why I disconnect the thing before I get home; have had the RWAL activate at the most inopportune times. LIke when I am towing 10K of cattle, hay, etc, and some bimbo in a SUV pulls out in front of me, and I have to rely on 11x2 trailer brakes. Same with airbags (no, NOT the wife and mother-in-law in the front seat together)- good way to get a whihplash and a broken nose, though there are just enough people who walk away from a totalled vehicle for the safety Nazis to keep the flame going... ... .

 

[mazdarotary]

Hey 1stgen,



How would one disconnect this system if I can't figure out how to fix it?And also is there any affest on braking?Any long term effect on pad/shoe wear?Thanks for the input guys. I think I will look into fixing the problem this weekend. Oh yeah what does the anti lock unit look like behind the glove box?Which wire do I ground to get the code?Thanks again.



Chris

92 D250 CC

74 Mazda Rotary truck

"new" 04 Mazda RX-8 nordic green mica

83 RX-7 soon to be parted out

 

[cdrider]

mazdarotary,

I had a similar situation--I fixed mine with a new sensor.

If the brake/tail-light fuse is verified to be good, check the sensor on top of the differential. You need to pull the plug off and take a reading with an ohm meter--it should read approx. 1300 ohms between the terminals. If it is way low or zero, you can get a replacement from NAPA for about $35. 00.

 

[Philip]

To disconnect the system. Pull the glove box out. The controller is located behind it. Just unplug it.



My brother in law had a 91. 5 with the ABS. I was riding with him one time. He had to climb all over the brakes because of a stupid driver. When the antilock kicked in the truck went faster. It droped the pedal to the floor. He had to hit the pedal agin. It was close. We almost hit the clown. The ABS is not hooked up on my truck. If I need or want 6 wheels sliding I controll it. Not some engineer at DC.

 

[mazdarotary]

Hey guys I just checked the rwal sensor at the rear end. I got 1. 477k ohms of resistance. Is that good?Also I grounded the diagnostic wire and got the anti lock light flashing. I got the light on pretty steady at first then 6 flashes after that. So I think its code 7. Which in my FSM shows Electronic control module fuse pellet open(what ever that means),isolation output missing(again I have no clue with that one),or valve wiring shorted to ground. Where should I go from here?I am lost.



Chris

 

[Paychk]

The ohm value for the RWAL sensor in the differential should read 1000-2500 ohms, and put out 650 millivolts when the wheels are spinning at 5 MPH. Read the ohms at the 14 pin connector of the control module, pins 13 & 14 (looking at connector on the module, pin 1 is bottom row left most, 14 is top row right most). Pin 13 will have a white wire violet stripe and pin 14 will be a red wire with violet stripe.

 

[mazdarotary]

Hey guys while thinking it over and looking at the light flashing here is what it is doing

long-short-short-short-short-short-long. Now what code would that be?6-7,maybe even 5?I am lost.



Paychk i got 1477 ohms. That is within spec right?Thanks again guys.



Chris

 

[Philip]

The FSM states to count all the flashes. The long flash at the start is indicates the begining of the test. It doesn't say in the FSM but I would think the long flash at the end would be to signal the end of test.



It states you must count the long flash along with the short flashes for an accurate fault code count.



Yours comes out to a 7 = Electronic control module fuse pellet open, isolation output missing, or valve wiring to ground.



The first part is most likely a protection fuse built into the module board assy.



The output missing could be caused from the the first item.



The Valve wireing to ground might be the cause of the first two.