ABS and Brake light on...

[gnslngr]

I've searched several times to try to find my problem with no help. So here is another brake issue.
I have an 2002 5.9 Diesel 2500 4x4 with 4 wheel ABS.

My ABS and brake light is on. Changed front pads. Changed the front left wheel bearing and of course hooked up the sensor. I still have the ABS/ brake light on. I checked my speed sensor on the diff and it shows 1.8 Ohms. My speedo works fine. I had Oreillys scan it and got a code "25" which is left front signal erratic and left front signal circuit malfunction. So I'm thinking my issues is from where I plugged in the new sensor up to the module because I had the lights on before I changed the bearing and sensor. If I turn the truck on (not running) all the lights come on then go off but then the ABS/brake lights come right back on. We cleared the codes and as soon as I got any worthy speed up the lights come right back on....PLEASE help!! Thank you very much!!

 

[Naidni]

is the problem consistent, is the light on all the time or is the trouble intermittent.
Others might disagree but in this situation, I'd start replacing things...cheapest fix to most expensive. if you're sure the ohm reading on the sensor is supposed to be 1.8 and you have ruled it out as a possible malfunction check the wire leading to the sensor. does it have continuity?

 

[WilliamS]

wheel speed sensor or tone ring on axle

 

[muddy12]

Are you sure the speedometer is still working at all speeds?

Had the same lights come on, on the ‘99 that I used to have. At first, the speedometer only quit working at very low speeds. Nothing below 5 MPH, but worked fine at 6+MPH. As time went by, the “no reading” speed gradually went up.

Also worth noting, even thought the ohm reading may be within spec, it’s a good idea to pull the sensor and inspect it.
The sensors are somewhat magnetic and can pick up particles from the dif fluid, which will throw off the reading.


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[gnslngr]

Thank you for the input. I did go ahead and replace the rear diff sensor after I snapped it off. So I got a chance to see the tone ring AND change my diff oil. After reassembling started up the truck and lights still on. Now I noticed when I hook up a scanner I get an ABS light and chime then my odometer reads NO BUS then the scanner comes back with "no communication" error... I did the key trick of on and off three times to clear all codes P ecu pcm done. Lights still on....