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Discussion Starter · #1 ·
2001 Dakota 4WD, 4.7

Brake and ABS light came on a while back. Can not for the life of me figure out why.
Lights are not on when I start the car, but come on when I hit 35mph like clockwork.

Brakes feel fine. Plenty of fluid. Sound fine. E-brake works. ABS does not work (I'm assuming it's purposely disabled because of the brake light). No speedometer issues.

No ABS sensors on front wheels- one in the back. Tested fine, but I replaced it anyway.
Replaced stoplight switch twice.
Lights still on.

Finally, out of frustration, I took it to a shop. They said the E-brake was 'stuck on' and this had damaged the drums. They replaced the drums (but said the shoes were fine). I drove home- as soon as I hit 35, lights turned back on. I called the shop, they said they only inspected the brakes, and a new appointment would be required to check out any brake light issues. Needless to say, not thrilled about taking it back there.

Anyone else had this issue? Solved it?
 

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2003 Dakota Sport, club cab, 3.9L V6, 5 speed manual
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I doubt that your E-brake was the problem. If it had been, the brake light would have been on all the time. There are three things that will illuminate the brake light: (1) different pressures sensed between front and rear brakes (indicating a leak in one of those braking systems), (2) parking brake is engaged, and (3) a fault in the ABS system. So whenever there is a fault in the ABS system, it will illuminate both lights.

Your Dakota has RWAL -- Rear Wheel (only) Anti Lock brakes. It is controlled and monitored by the Controller Antilock Brake (CAB) located near the power brake booster. This unit checks electrical circuits and other components and if it finds a problem it will illuminate the ABS light, which also illuminates the brake light. If you have a factory DRBIII tool, or a high end scanner that can read more than just the PCM, you should find codes for whatever fault the CAB has detected.

I'm guessing it's a faulty CAB itself, but only a capable code reader device can tell for sure. You may want to check a salvage yard. Most 2000-2003 had RWAL (rather than full ABS) and you may find a used unit at a reasonable price.
 

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Discussion Starter · #3 ·
I doubt that your E-brake was the problem. If it had been, the brake light would have been on all the time. There are three things that will illuminate the brake light: (1) different pressures sensed between front and rear brakes (indicating a leak in one of those braking systems), (2) parking brake is engaged, and (3) a fault in the ABS system. So whenever there is a fault in the ABS system, it will illuminate both lights.

Your Dakota has RWAL -- Rear Wheel (only) Anti Lock brakes. It is controlled and monitored by the Controller Antilock Brake (CAB) located near the power brake booster. This unit checks electrical circuits and other components and if it finds a problem it will illuminate the ABS light, which also illuminates the brake light. If you have a factory DRBIII tool, or a high end scanner that can read more than just the PCM, you should find codes for whatever fault the CAB has detected.

I'm guessing it's a faulty CAB itself, but only a capable code reader device can tell for sure. You may want to check a salvage yard. Most 2000-2003 had RWAL (rather than full ABS) and you may find a used unit at a reasonable price.
Appreciate the info very much. I knew about the RWAL, but I wasn’t familiar with the CAB.
I only have a basic code reader, but I’ll try and find a place that can scan for more advanced codes. And I do have a couple nearby salvage yards- I’ll see if I can get ahold of a replacement CAB.

I noticed in another post someone said if the CAB is switched out, it has to be reprogrammed using a DRBIII. Do you know if that’s necessary? Or can I just switch them out?
 

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2003 Dakota Sport, club cab, 3.9L V6, 5 speed manual
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I'm not sure on the programming of the CAB. I doubt that it's that sophisticated. I've been doing a little more reading online (Kelsey-Hayes RWAL Antilock Brakes) and it appears the CAB can only hold one trouble code at a time, and apparently doesn't automatically clear the code if the problem goes away. It says you can pull the fuse for a short time and see if the code clears (I suggest 30 seconds or so). I just looked it up and the fuse should be #8, labeled ABS, in the Power Distribution Center under the hood, and should be a 40 amp fuse. You could try this -- it would be a really cheap fix if it works!
 

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Discussion Starter · #5 ·
I'm not sure on the programming of the CAB. I doubt that it's that sophisticated. I've been doing a little more reading online (Kelsey-Hayes RWAL Antilock Brakes) and it appears the CAB can only hold one trouble code at a time, and apparently doesn't automatically clear the code if the problem goes away. It says you can pull the fuse for a short time and see if the code clears (I suggest 30 seconds or so). I just looked it up and the fuse should be #8, labeled ABS, in the Power Distribution Center under the hood, and should be a 40 amp fuse. You could try this -- it would be a really cheap fix if it works!
I just tried pulling the fuse. As soon as I hit 35, they came back on. Thanks for the idea though!
I’ll try and find a way to read the code and/or a replacement CAB sometime this week. Appreciate the link also- lot of information there.
 

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2003 RT with 5.9
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322 Posts
My ABS & BRAKE light came on a few years ago & when I got under it I found that the wire harness to my rear speed sensor mounted on the rear diff had ben damaged. I bought a new sensor that came with the wiring & that solved my problem.
 
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