Brake Issue

Plugger49 · September 5, 2017

Hi all-old new guy. After reading a few member posts,I thought I'd join in. The easiest join I've experienced. Some forums make it extremely difficult.Anyway,the problem I'm having is that my ABS brakes would pulsate at very low speed and nearly fail to stop the truck. I went ahead and pulled the fuse,so brakes are working the old style way. Of course the ABS & Brake lights are constantly on and annoying. I've read the ground behind drivers tire(on frame), could be an issue, and others (wherever they are). To make clear- the dash lights were never on,until I pulled fuse,when this was going on. I also have taillight issues,but-one thing at a time. I have two Sierras-1500 & 3500-1-Ton. I'm referring to the '02 1500 here. It has 103K,I'm the second owner. The original owner NEVER washed the undercarriage. I've got rust issues (only undercarriage) out the Wahzoo! Thanks in advance.

Supreme Pizza · September 5, 2017

Hi,

Normally the ABS light would come on if there was an issue (such as a burnt out fuse). I had issues with my ABS light coming on, and I went through all the steps. First I took it to a shop that would run the ABS codes for free. It showed an ABS module fault. I cleaned all the electrical connections, and cleaned the grounding point on the frame as well. That stuff didn't work. Replacing the module would have been expensive, and it would have to be re-programmed by the dealer. Ultimately, I had to Dremel the rusted module bolts off, use a razor blade to cut the seal in order to open the module, then I had to inspect the circuit board with a huge magnifying glass for a bad solder point. After re-soldering the board, re-sealing the unit, and dealing with the rusted bolt issue, the ABS lights stopped coming on and everything seems to be working great. My total repair cost was $0.00. If I were you, I would be looking at the ground, the speed sensors on each wheel, and maybe the module itself. I think your best place to start is running the codes. Just call around and ask someone if they charge anything to check them. It takes about 22 seconds to check the codes, but many shops have a "1 hour minimum" labor charge (plus tax, plus shop supplies, plus hazardous material disposal fee, etc etc etc.)

DareDog · September 6, 2017

Have a '05 here with same issue. Almost ran in to the front of the barn and thought truck was not going to stop. so pulled the fuse. I think the sensor on wheel bearing went bad and that is also a sign that the wheel bearing is going bad also.

mxz905 · September 6, 2017

Likely sensors in one or both of the front wheel hubs. Some times you can take the sensor out and clean up the mating surface, often times the sensor will break and you will need a new one. What happens is a bit of rust forms between the exterior hub surface and where the sensor screws onto it. This raises the sensor ever so slightly but just enough that the end of the sensor is too far from the inner portion of the hub and incorrectly identifies a wheel lock up scenario. The first time this happened to me I ended up replacing the hubs due to a bad wheel bearing in just a few months the second time this happened it's been about a year and still no issues with wheel bearings. Knock on wood.

Plugger49 · September 7, 2017

Sorry it took me awhile to get back. I couldn't figure out how and I'm still not sure. Thanks to the three of you. Anyway- I cleaned up the ground under driver -no change. I can't find an actual ground anywhere in the back. Thinking there isn't another. Truck pulls a little to the left when braking,I'll pull everything and see what the sensor looks like. If no luck with that,I'll have to get at the module (WHAAA). Process of elimination bites,but other than taking it to a shop,where I'm probably going to get robbed,I don't have a choice. I hate paying for something that I can do,but this is more than I have the energy and patience for-LOL. I also have a taillight problem,where I apply the brakes-the directionals fast flash on dash and dimly (both sides) out back. Let me know if you (anyone) has any thoughts-Thanks

Supreme Pizza · September 7, 2017

I believe that there is only one ground for the module. I doubt that the module is the problem, but its possible. If the module is not working correctly, its self diagnostic should throw a code/dash light. I would really be looking at the wheel sensors. I think that's the problem if I had to guess. When your slowing down, the sensors detect the wheel rotation and if the "signal" is low, it could drop out all together and fool the sensor and module into thinking that the wheel stopped, triggering the ABS. Wait.............. Are the tires all the same size? Same tread depth? Same air pressure? Stock tire size, or have they been changed to a larger or smaller size? If the rotation on one wheel is different, that will mess things up. Also, if you get new tires, the size needs to be the same - otherwise your supposed to re-program the module to calculate using the new tire size.

Supreme Pizza · September 7, 2017

To get back to this page, highlight the address using your mouse. Then right click and hit "copy". Then go to the desktop and right click. Move the cursor to "new" and select "text document". Then open that document and then right click, then hit paste. Make sure you save the file. (it asks you if you want to save when you try to close it). Then just copy and past that address into the browser, and your back here again. Or click on the "star" in the upper right corner to access the favorites (Chome).

Plugger49 · September 7, 2017

Thanks Starman for all your help. The tires are about two years old,the original (correct) size. They seem to be wearing evenly,I had wheels balanced when I bought them. As far as equal air- good question-I'll check that. But Whaaaw,I would never have guessed,a minor difference would cause all this grief.... I took a photo of your instructions on how to get to my thread,and for good reason-Holy S⚡️T, I can get into Fort Knox easier. I'll check

the air, then the left(seems to pull at low speed check)sensor. I've wasted ALOT of time so far,and got basically Nowhere, but I'm an extremely Thick SOB and hate letting something go-HaHa

repairman54 · September 8, 2017

Ya gotta get the ABS codes read. I had a couple of wheel sensors go on my old '99 Yukon over the years I had it and the ABS module codes will tell you which sensor is bad.

A great scan tool is a must today, the price of one shop trip will buy a great CAN system capable one. My '11 Tahoe ONLY has 41 modules in it and it's gonna get worse. The old Yuk only had about 12 modules in it.

I also had the exterior rust raise the sensor up out of the wheel bearing on my Yuk like MXZ905 describes.

Supreme Pizza · September 8, 2017

http://www.ebay.com/itm/Automotive-U281-OBD2-Scanner-Code-Reader-SRS-ABS-Diagnostic-Scan-Reset-Orange-/112488441724?hash=item1a30d5677c:g:CVUAAOSw74FXPWGl

Plugger49 · September 13, 2017

Hey, I solved the taillight problem. I replaced the rusted circuit board and found two burnt wires along back frame. This was while I was checking foe ABS grounds etc.. I'm going to replace the left hub next. Just touching base, I appreciate all of your input. I'm an old guy who still likes to learn new S⚡️T!