I have a 99 ram 1500. The speedometer quite working and the check engine light, brake light, and the abd light are on.the trick also holds out to 3000 rpms before shifting. I've had this problem before and changed my abs speed sensor on the rear diff. Thought that was the problem again changed it and the vss (vehicle speed sensor) on the side of the transsmision and neither have fixed the problem. I took the main plug of the abs module abd it was clean aand dry but I cleaned it anyways and still nothing can anyone give me any info? Thanks in advance

 

Welcome to DF!

I suspect more than one problem, but, start with the ABS sensor on the rear axle. That should take of of at least some of it.

 

I have already changed it and the vss yesterday still nothing.

 

That's not good.... Verify you are getting power TO the sensors. Should be in the neighborhood of 5 to 8 volts.

You can download a service manual from this thread. Wiring diagrams are in there.

 

I'll see what happens thanks

 

I also have the same issue! My speedometer doesn't work and both the ABS and BRAKE lights stay on. Also experiencing "shifting problems" from the transmission. I've replaced both the rear end sensor and the speed sensor in the transmission. Also tested the plug for any moisture. (Looked good to me, but cleaned them anyhow.) Any other ideas or has your problem been resolved?? Thank you! I just got this truck... really hope to get this fixed soon. I've read online that the ABS module (the "brain" part) can cause this? It's about $100 at a part store. I would GREATLY appreciate any advice!

 

Did you reset the pcm after the part swap? You need to erase the old code.

 

Do a cluster test first, to verify everything there is working. (Just hold in the Trip Reset button, and turn the ignition on, wait for the test to start, and let go. will flash all the lights, and sweep all the gauges.)

If that's ok, verify you have the proper voltage at the various sensors.

 

Cluster test was okay. All the lights and gauges worked (including the speedometer.) I will check the voltages at the sensors next. I read they should range from 8-12 volts?

 

I left the battery unhooked for a day. That would reset it right? It gave a P0500 code that I had cleared after replacing both sensors. It hasn't come back on.