I touched on this a little in another thread a while back. Finally getting to it.

 My abs light flashes constantly. The red brake light on the dash is not on, only the flashing abs light.

 I have read through the abs article and it refers to the abs/brake light both being on. So that didn't really give me a definite answer to my problem

Abs light flashing, no parking brake light on and the speedo is working fine, cruise control works, brake lights come on when brakes applied as they should and 4wd light comes on and engages as it should. I did replace one front wheel speed sensor yesterday, planning on doing the other side either today or tomorrow but I feel it may not be the issue. 

 Anyone else ever run into this?

 Any advise would be appreciated. The light is just annoying. 

If you know someone with a snap on scanner I believe it will read abs codes

Maybe the module going bad, scanner would be nice to know for sure.

3 hours ago, Doubletrouble said:

 I touched on this a little in another thread a while back. Finally getting to it.

 My abs light flashes constantly. The red brake light on the dash is not on, only the flashing abs light.

 I have read through the abs article and it refers to the abs/brake light both being on. So that didn't really give me a definite answer to my problem

Abs light flashing, no parking brake light on and the speedo is working fine, cruise control works, brake lights come on when brakes applied as they should and 4wd light comes on and engages as it should. I did replace one front wheel speed sensor yesterday, planning on doing the other side either today or tomorrow but I feel it may not be the issue. 

 Anyone else ever run into this?

 Any advise would be appreciated. The light is just annoying. 

My ABS light has just started randomly and occasionally flashing.  I'll have to keep an eye on it.  I'm interested in knowing what you learn here.  Keep us posted please.

A buddy has a snap on scanner..I'll have to catch up with him soon and check it out

The rear axle I believe has a sensor on it. They can go bad or have a wonky connection, it can trigger the light. If the ABS light burns out, the brake light stays on. 

 

The proportioning valve may be triggering the light as well.

 

Those may be 12v exclusive issues, except the rear axle sensor.

Edited October 12, 20204 yr by That Guy

On 10/11/2020 at 6:43 PM, That Guy said:

The rear axle I believe has a sensor on it. They can go bad or have a wonky connection, it can trigger the light. If the ABS light burns out, the brake light stays on. 

 

The proportioning valve may be triggering the light as well.

 

Those may be 12v exclusive issues, except the rear axle sensor.

You're right, I had an issue with abs coming on and changed the rear sensor, still did it, so changed front sensors, still did it, few years later I changed front wheel hubs with sensors, still did it, then I had abs module rebuild, still did it, well I changed the rear sensor again and no more light...... Poop happens, don't think new sensor is always good.

My problem was the connection where the wires come together at the very top of the pumpkin on the diff.

I put a jumper wire in and my light went off...jumped up and down for joy,  mangled a hose clamp around it till I got a another connection and three years later it still got the hose clamp on it making the connection right at the very top of the pumpkin.

I'll have to check the rear sensor as well then I guess. I was going to have my buddy check it with his scanner but they changed my shifts at work again and I won't be able to make it there tomorrow as planned.

Rear axle speed sensor typically will see as a goofy speedometer that doesn't work right all the time. Like get below 30 MPH and drops to 0 or something odd. That is a failed sensor. Now the front to sensors if you suspect the front replace in pairs. 

3 hours ago, Mopar1973Man said:

Rear axle speed sensor typically will see as a goofy speedometer that doesn't work right all the time. Like get below 30 MPH and drops to 0 or something odd. That is a failed sensor. Now the front to sensors if you suspect the front replace in pairs. 

My speedometer always worker fine but abs/brake light would come and go. After changing front sensors and later hubs with sensors again I changed rear sensor again and it fixed my issue. But you are right, usually you'd lose spedo, like truck we had at work 2500 gasser wire was rubbing on sway bar and got shorted out, I fixed the wire and all came back to normal, spedo didn't work with bad wire.

******UPDATE******

So, it's been a little while but I finally got the time to stop by my buddy's shop and have him plug in his snap-on scanner to see what's going on.

 It showed 2 codes in the abs system

1. Revs per mile to high

2. Tone wheel tooth count off

 Wording may be slightly off but that's what they said in a nut shell.

 Problem was the tire size was entered wrong. Once that was corrected the light was out.

 After driving the truck that afternoon I noticed the speedo was off by 6mph at 60mph (speedo showed 66mph at 60).

 I called him and we deduced that the gear ratio is also entered incorrectly. He noticed it showed a 3.92 gear. He didn't think much of it since his ram 1500 is the same ratio. I told him it's a 3.55 gear, he confirmed it with the vin number. So I'll be going back soon to get that setting changed and the problem should be solved.

 Just wanted to update for anyone having this issue now or in the future.

***Final Update***

 I had my buddy hook up to it again with his snap-on scanner. He found that the rear axle setting was on 9.5", the options were 9.5 and Dana. He set that to Dana since the truck has a Dana 80 rear and Dana 60 front axles. Tire size was checked again to be sure it stayed set on my tire size. By changing the axle setting it had changed the size again so he reset that to the proper size.

 All is good so far. I haven't driven it much, about 10 miles since this but as of now, no abs light and the speedo is now spot on compared to my Garmin gps. Glad that annoying light is off. 

 Just wanted to post final results so it may help someone else in the future.

Yup I kind of figure there was something a miss. ABS is really fussy about being lied to with oversized tires and improper tone ring values.

Yes it seems they are. In my case, running factory size tires, no major mods at all, I believe someone was in the computer and didn't know what they were doing.

Hard to tell sometimes people have tires sizes in the signature but then on the other side when they don't post tire sized I tend to assume there is oversized tires possible being majority of people do run larger wheels and tires. 

Nope, not in my case. I was very lucky, when I bought the truck it had a brand new set of 6 (dually) cooper tires on her. Didn't have more than 1000 miles on them, all factory size per door sticker. It may have had oversize tires before that, no way of me knowing.

On 11/18/2020 at 11:08 AM, Mopar1973Man said:

in the signature

Where are the signatures, I haven't seen them in a while

I see yours. You cant see mine???

Sigs don't show on mobile.

1 hour ago, dripley said:

I see yours. You cant see mine???

No

 

1 hour ago, That Guy said:

Sigs don't show on mobile.

I see, not really. Ok makes sense thanks