2nd Gen Non-Engine/Transmission Brake warning light & Speedometer

[BJesik]

Help from TDR friends,



I have a 2000 Ram 2500 Quad Cab, CTD, 4x4, 6 speed std. Yesterday I had 3 things happen simultaneously and hope someone can help me. After returning from out of town I started my truck and the ABS and parking brake lights stayed on. I also noticed that my speedometer would drop to zero when I slowed to 20 mph and would remain on zero until my speed increased to 20 mph them would jump up and work normally above that speed. Are all these things connected or is it just coincidence that more than 1 thing went wrong at the same time. Any help would be greatly appreciated. Performance etc. seems to be unaffected.



Thanks Bjesik

 

[AHunter]

my brake light and abs light came on too and will not go off on my 97

 

[tgordon]

Hunter, anytime you have a malfunction in your ABS system the brake light comes on. It could be as simple as a broken wire, my wire to the sensor is broken, or it could be something much worse. I do not get along with ABS personally and would like to figure out how to get the lights off, but have not had the time to do it yet.



Troy

 

[B.G. Smith]

Help from TDR friends,



I have a 2000 Ram 2500 Quad Cab, CTD, 4x4, 6 speed std. Yesterday I had 3 things happen simultaneously and hope someone can help me. After returning from out of town I started my truck and the ABS and parking brake lights stayed on. I also noticed that my speedometer would drop to zero when I slowed to 20 mph and would remain on zero until my speed increased to 20 mph them would jump up and work normally above that speed. Are all these things connected or is it just coincidence that more than 1 thing went wrong at the same time. Any help would be greatly appreciated. Performance etc. seems to be unaffected.



Thanks Bjesik

The speed sensor and the ABS sensor at the rear wheels are one and the same, it is mounted in the top of the differential and is fairly easy to replace I have read.

 

[fest3er]

Help from TDR friends,



I have a 2000 Ram 2500 Quad Cab, CTD, 4x4, 6 speed std. Yesterday I had 3 things happen simultaneously and hope someone can help me. After returning from out of town I started my truck and the ABS and parking brake lights stayed on. I also noticed that my speedometer would drop to zero when I slowed to 20 mph and would remain on zero until my speed increased to 20 mph them would jump up and work normally above that speed. Are all these things connected or is it just coincidence that more than 1 thing went wrong at the same time. Any help would be greatly appreciated. Performance etc. seems to be unaffected.



Thanks Bjesik

The fact that the speedometer works at all shows that the CAB (controller, anti-lock brake) is functioning. The speedometer dropping to zero 'too soon' means that the CAB is not seeing enough voltage from the sensor at low speed. Normally, the speedometer and odometer stop registering at around 2 MPH due to the natural voltage drop-off of the sensor at low speeds. Unplug and reconnect both ends of the circuit (at the sensor and at the CAB). If this doesn't fix it, then check the sensor itself; remove it from the diff and visually inspect it for physical damage. Next, ensure the CAB connections are good.



4-wheel ABS, if you have it, could explain why the warning lights stay on: the CAB is detecting the front sensors but not the rear, or it is detecting motion on the front but not the rear.



If fiddling with the connectors fixes the problem, spritz some contact cleaner on them, plug and unplug them a few times, then dry them off and plug 'em back in. And make sure they are locked in place.



N

 

[JCarlisle]

I have this problem on my 2000 3500, and would like to disable the ABS, and eliminate the dash lights, and keed the emer brake light?

 

[billvicky]

My '99 w/ auto trans did the same thing about a year ago. I was told the speed sensor in the rear differential did the ABS and the speedometer below 30 mph. Above 30 mph a sensor in the trans took over the speedometer. Changed the sensor in the differential, $35 from dealer, ABS/brake lights went out and speedo worked below 30 again.

 

[BJesik]

Thanks very much, my friend. This will be a big help.

 

[BJesik]

I believe you have solved my problem. I will replace the speed sensor and see what happens. Thanks so much for your help. Much appreciated. BJesik