Check your brake fluid level. If it is low it can trigger the brake and ABS light on the dash ( BTDT ). The sensor in the "pumpkin" is the Rear Wheel Anti-lock Sensor and has no bearing on the speedo at all. The speedo is affected by the tranny sensor and these rarely fail. Be careful when removing the ABS sensor as you can easily break the plastic bottom off of it. Then you will get to change out your diff fluid as well as retrieve the broken plastic ( BTDT ). Hope this helps. Shane

 

The differential sensor *does* seem to affect the speedo; I had the problem of ABS/brake coming on and the speedo would stay at 0 until I got above 30mph. The next tank of gas then gave 7mpg as compared to my normal 14-16 range; both of those problems were fixed and the lights went out after replacing the rear speed sensor (the MPG was not actually a loss of MPG but speedo broken -> odometer would not register any miles driven under 30mph which lowered the apparent number of miles).

Make sure you get the Mopar version - I originally got the Advance Auto/PartsAmerica version for ~43 and was going to put it in at the same time as changing the differential fluid since I had it on a lift; the Advance version fit in place of the old one but on mine at least (98 1500 2WD 9.25 axle) had a 3 wire connector instead of the trucks 2-wire setup. Going to the dealer produced a 2-wire version along with the service history from the previous owner indicating that the last time he had had the fluid changed was 90K ago which may have cooked the sensor. If you are changing it a 15mm deep socket will reduce the maneuvering needed to get the mounting stud out.

 

So, I'm guessing that everyone agrees that it is the speed sensor, or the Rear wheel anti-lock sensor? Is that the same thing? I'm having the same problem in a 2001 Sport 4x4. ABS and brake lights come on at exactly 40mph every time and stay on until I turn the truck off then back on. My anti-lock brakes aren't anti-lock anymore. When I brake hard it locks up and tries to slide sideways. I found that out on the freeway the other day. And I'm getting about 7-8 mpg. My brake fluid level is good and my fuses are all good. So whats the deal now? Go for the sensors?

 

Helloooooooo??????? Helloooooooooo? I think I heard an echo.

 

Howdy,
You could try the sensors, I would/did. The odds of it working for you are greater than not. At least that's what I've been led to believe. Although, I've now got two new ABS sensors and the same problem.

 

yes a leaking break line will cause it...i poped a break line and guess which lights came on. fixed the lines and the lights went out.

 

I did my front ball joitns and broke a front ABS sensor. Caused both lights to come on, could only get one at the dealer 200 bucks. No codes were set, checked with my reader. Hope its not the front one it a bit of a pain in the *** to change as it probably stuck and half will stay behing in the hole.

2001 Sport 4X4.

Chris