01-28-2015, 05:26 PM
DIY ABS Module Rebuild - ABS Pump Won't Shut Off - Issue Solved
06-17-2013, 07:30 AM
#41
ABS light still on
After following all of the directions and replacing the MOSFET chip everything worked great for a while. Now I have a situation where my ABS light is always on but the pump no longer runs continuously. I'm wondering if it is a bad MOSFET or perhaps my bad soldering. If the pump is not running continuously but the ABS light is on doesn't this point to a bad sensor on one of the wheels? I did replace the rear sensor. that was easy. Any advise on my next step?
08-20-2013, 11:20 AM
#42
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Has anybody ran into the pump still running even after fixing the module? I have a 2003 4.6L 4x4, my pump was running so I rebuilt my module, using this thread (thank you very much! btw) and the pump still runs. To be sure I didn't fry my circuit board in the process, I bought a brand new module, plugged it in and same problem! I'm wondering what to look for next?
01-04-2014, 09:26 PM
#43
Does anyone know if this will work on a 97 with a 5.4? Thing is my issue is a little different. I'm getting hard ABS braking as soon as I apply the brakes. I pulled the fuses for the abs and it stopped but I'd like to fix it. I went ahead and ordered the parts but figured I'd ask before I do it.
01-08-2014, 05:46 PM
#45
02-10-2014, 03:10 PM
#46
Thanks to khsonic03! Fantastic fix!
I joined this forum just to say "thanks!" to khsonic03 for this amazing fix. I have a 2001 F-150 with 92K that I bought sight unseen from a municipality. I like those kinds of vehicles because when it's the city, county or state paying for the maintenance, it tends to get done. However, when the time comes that they let them loose, there's always something "up". In this case, the ABS light. In my case, the motor wasn't running, but that's because the fuse had been pulled.
Well, I have to say, this was one of the most satisfying fixes I have ever done in decades of amateur mechanics. The idea that we can sock it to the stealership and do the fix for a few bucks is awesome, and the feeling when the ABS light goes off, well, nothing short of magical! So thanks!
I just wanted to add a handful of my own tips, especially to those who are unfamiliar with board-level repairs.
1. Let's start with those darn bolts holding the module on. Who the heck designed that? My solution was to use a flexible drill extension and drill the heads off. Once off, and the module removed, what remained of the bolts unscrewed easily with vise-grips. Yes, stainless steel replacements were the way to go.
2. Rather than using a cutting wheel on my Dremel, I used a tiny burr point that was easily able to find its way through the glue without going too deep into the case. I used the same burr to remove the small panel above the heat sink. This felt much more precise and controllable than the cutting wheel (which I also tried). As a result, the case halves had almost no damage and went together again super easily with a couple of c-clamps and some epoxy.
3. Removing the MOSFET heat sink might unnerve someone who's not used to board level repair, as it looks as though it's on pretty hard. However, I found that it was easy to pry it off by inserting a tool behind it and leveraging against the casing. Popped right off. Phew! Big relief!
4. When removing the faulty MOSFET (mine looked absolutely normal, btw), use a little upward pressure on each leg while applying the soldering iron. The legs will lift as soon as the solder melts, as they are mounted on top of the board, and not through it. Once the two legs are lifted, turn your attention to the wide flat-bar connection on the other side of the MOSFET, soldered (on mine) in three places, but it's all one connection. On my board, this wanted to lift the board pad, so I had to use a tiny screwdriver to hold it flat while I worked off the MOSFET.
5. For installation, I used a pair of tweezers, resting horizontally on the circuit board, to hold the new MOSFET in place while I completed the new solder joints on the legs. Once those were done, it was easy to do the other side. Note that one of the legs sits atop a circuit board "island", so watch that you don't inadvertently bridge it across to an adjacent part of the board. Also, if you are not used to soldering, practice on something else first!! Finally, attach a small heat-sink plier to each leg before you start soldering it, especially if you are going slowly. You don't want to overheat your new chip.
6. Finally, it's worth using a multimeter on a continuity "beep" setting to test your new solder joints. You do this by identifying another joint that's on the same piece of board as the one you just did, and making sure there's continuity between them. Sometimes it's a bit tricky to figure out, but for example, one of the MOSFET pins connects to the ground terminals on the connector. So you can touch one probe to the MOSFET pin and the other to the ground connector. If you have a good solder joint, it will beep. Rather do the test now than find out you got a dry joint. For the other pins, you just have to follow the areas of copper that lie just under the board surface until you find something that connects. Oh, by the way, the little short leg between the two other legs is connected to the chip-wide bar on the back, so that's a good way to test that joint, by testing from that little pin to the other side of the board.
7. Although you should be "good to go" once this is done, it's worth installing the unit before you glue it all back together again. I did that, and got a fright, because although two of the codes had resolved, C1095 was still showing, and the ABS light was still on. Was the pump motor blown? I pulled out a power supply and ran 12v to the motor and it spun fine. The issue, it turned out, was that I had not seated the motor connector all the way into the ABS module. It has a water-resistant connector that requires a mighty shove in to make sure its fully seated. With that done, bingo!! No ABS light, and I'm set.
All in all, a wonderful solution to a common problem, and one that's certainly manageable by most DIYers. If I can do it, well . . . anyone can. Once again, thanks khsonic03!
Well, I have to say, this was one of the most satisfying fixes I have ever done in decades of amateur mechanics. The idea that we can sock it to the stealership and do the fix for a few bucks is awesome, and the feeling when the ABS light goes off, well, nothing short of magical! So thanks!
I just wanted to add a handful of my own tips, especially to those who are unfamiliar with board-level repairs.
1. Let's start with those darn bolts holding the module on. Who the heck designed that? My solution was to use a flexible drill extension and drill the heads off. Once off, and the module removed, what remained of the bolts unscrewed easily with vise-grips. Yes, stainless steel replacements were the way to go.
2. Rather than using a cutting wheel on my Dremel, I used a tiny burr point that was easily able to find its way through the glue without going too deep into the case. I used the same burr to remove the small panel above the heat sink. This felt much more precise and controllable than the cutting wheel (which I also tried). As a result, the case halves had almost no damage and went together again super easily with a couple of c-clamps and some epoxy.
3. Removing the MOSFET heat sink might unnerve someone who's not used to board level repair, as it looks as though it's on pretty hard. However, I found that it was easy to pry it off by inserting a tool behind it and leveraging against the casing. Popped right off. Phew! Big relief!
4. When removing the faulty MOSFET (mine looked absolutely normal, btw), use a little upward pressure on each leg while applying the soldering iron. The legs will lift as soon as the solder melts, as they are mounted on top of the board, and not through it. Once the two legs are lifted, turn your attention to the wide flat-bar connection on the other side of the MOSFET, soldered (on mine) in three places, but it's all one connection. On my board, this wanted to lift the board pad, so I had to use a tiny screwdriver to hold it flat while I worked off the MOSFET.
5. For installation, I used a pair of tweezers, resting horizontally on the circuit board, to hold the new MOSFET in place while I completed the new solder joints on the legs. Once those were done, it was easy to do the other side. Note that one of the legs sits atop a circuit board "island", so watch that you don't inadvertently bridge it across to an adjacent part of the board. Also, if you are not used to soldering, practice on something else first!! Finally, attach a small heat-sink plier to each leg before you start soldering it, especially if you are going slowly. You don't want to overheat your new chip.
6. Finally, it's worth using a multimeter on a continuity "beep" setting to test your new solder joints. You do this by identifying another joint that's on the same piece of board as the one you just did, and making sure there's continuity between them. Sometimes it's a bit tricky to figure out, but for example, one of the MOSFET pins connects to the ground terminals on the connector. So you can touch one probe to the MOSFET pin and the other to the ground connector. If you have a good solder joint, it will beep. Rather do the test now than find out you got a dry joint. For the other pins, you just have to follow the areas of copper that lie just under the board surface until you find something that connects. Oh, by the way, the little short leg between the two other legs is connected to the chip-wide bar on the back, so that's a good way to test that joint, by testing from that little pin to the other side of the board.
7. Although you should be "good to go" once this is done, it's worth installing the unit before you glue it all back together again. I did that, and got a fright, because although two of the codes had resolved, C1095 was still showing, and the ABS light was still on. Was the pump motor blown? I pulled out a power supply and ran 12v to the motor and it spun fine. The issue, it turned out, was that I had not seated the motor connector all the way into the ABS module. It has a water-resistant connector that requires a mighty shove in to make sure its fully seated. With that done, bingo!! No ABS light, and I'm set.
All in all, a wonderful solution to a common problem, and one that's certainly manageable by most DIYers. If I can do it, well . . . anyone can. Once again, thanks khsonic03!
05-22-2014, 02:56 PM
#47
ABS Module Rebuild - Replace Power Rely
Hi, hope some of the original posters to this thread are still watching replies. (I'll start a new post if necessary, but wanted to connect with the experts on this thread if possible.) I have what I think is a similar problem, except instead of the MOSFET being bad I think it is the ABS power relay. The ABS light on my 2001 F150 comes on intermittently and the error codes I get - C1185, C1198, C1214 - say it is the ABS power relay output circuit. Nosing around the internet I get that the power relay is internal to the module. True? If yes, is it a component I can replace using surgery similar to the rebuild offered in this thread?
05-31-2014, 05:21 PM
#48
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for a great treatise on this subject, very much appreciated.
06-13-2014, 08:39 AM
#50
abs module stays on
I have a 2000 f150 with a 4.6L engine rather than a 5.4L. Is the part number for the MOSFET the same for the 4.6L engine? I plan to try and remove it this weekend. Does anyone have a link or correct part number for the Mosfet. Mine does the same thing, had to pull the 50A fuse to silence it.