Check the sensor in the rear diff.... the aftermarket sensor are NOT of the same quality as the OEM guys......

 

Right...I get that aftermarket components can be of less-than-stellar quality.

But, if a bad sensor is triggering the warning lights, then the Rear Wheel ABS controller should throw out an error code for the sensor? I read that code out when the original sensor went bad and I replaced it. I am not getting that code (let alone any code), right now.

I have not tried pulling the battery, which resets the controller, and seeing if the warning lights still remain lit. I will try that over the weekend.

 

That sensor does not always give a code.So forget that. What brand did you buy? You can try disconnecting the plug and put it on and off a few times. (maybe corroded). Other than that, you may have a pinhole in the brake line running along side the gas tank.

 

If the ABS and BRAKE lights are on, and it is the speed sensor that is defective, then how would the ABS controller not give a code (I would expect code 6)? If the ABS controller is lighting the ABS and BRAKE warning lights for some other reason, then why is it not giving any code at all? A corroded connector would report a High Impeadance (code 9) or Low Impeadance (code 10) error to the ABS controller, tripping the controller to light the warning lights and record an error code.

This is why my main question seems to be: can the ABS and BRAKE warning lights be on without a trouble code from the ABS controller. If so, what are those possible causes?

I have no trouble replacing the speed sensor (I did it 15k miles ago), but seeing as how everything else (speedometer, cruise control, braking) is still working OK, I'd like to be sure that what I'm replacing is actually a bad part or will fix the problem. The last time I replaced the speed sensor, it was because the ABS and BRAKE warning lights were On and the ABS controller gave the appropriate code (code 6) for that failure. At that time, everything else was still functioning OK, too (speedometer, cruise control, braking).

Thanks for the reminder on the pinhole leak - I suffered that failure on the highway about 2.5yrs ago and I replaced that brake line (from the brake master cylinder to the rear axle). When THAT went, I knew it right away (as my braking sucked), and the brake fluid level really dropped. My brake fluid levels are fine, and there are no fluid leaks. I've since put stainless steel lines on the truck all the way around (did that about 1.5years ago).

Thanks for the guidance!

 

How are you reading codes?

 

via the Blink Codes, after pin 13 (Black wire) on the diagnostic connector has been temporarily grounded. Mine is a pre-'97, rear wheel ABS only, so this procedure works for getting the codes. This presented the speed sensor code the last time these lights came on and I made that repair. I removed the battery connection (cleared the codes) and have been fine for 3 years. Now the lights are on again, but the same procedure is resulting in No codes being output.

 

Grab the 96 service manual from the faq section here, and on page 5-62, do test 6. That is where the procedures led me for an abs/brake lite on, but, unable to pull codes.

 

Not all the sensors give off codes when they are bad. Like O2's for instance. I don't know why. It's just the way it is sometimes. Plus, you do technically have a code, the abs and brake light is on. Which may be the way Dodge made it.

 

HeyYou - thanks for the pointer to the service manual in the FAQ! Those instructions look perfect, and I'll start stepping through them and will report back what I find.

 

I went through the exact same thing. Turned out to be the abs control module itself. There was no codes because the there was no "communication" coming from the module. Except of course the brake and abs light.....

It was like my truck said you need to spend some money on me just because I feel like it.