My dad has a 00 Ram Van 1500 with the 318 motor.

He recently had the PCM updated. Shortly thereafter, maybe a week or so, the ABS and Brake lights came on. They come on after the truck idling or driving for 10 minutes. The important thing to note is that they'll come on after idling. Checked all the brake lines and wiring and didnt see anything broken or frayed. Read on multiple forums that the rear differential speed sensor could be the culprit. Replaced that. No such luck. Does anybody have any clues where to go next. I'm having problems figuring out where to go next and I'd hate to have him throw away money at the stealership if he doesnt have to(EX. Speed sensor $32 and half hour of our time.. Stealership wanted $230). Could the reflash of the PCM be causing the issue?? Is this a unrelated repair?

 

Welcome to DF
Anytime you either replace or flash a pcm on any trucks,ram van or 1500.You also need to clear the codes in the abs module,because the abs see a mismatch vin number and kicks the abs/brake lites on. Clear the codes with a scanner and it should be alright.

 

Thanks for the welcome.

Is this something i could do myself? I'm not extremely familiar with ABS modules, nor the inner workings of the ABS system. I only have a pocket scan OBD2 tool, and I'm already not throwing codes frpm the ABS and brake light being on. But I'm aware that the pocketscan tool only catches emission related issues.

 

You need an OBDII interface that allows you to clear your MIL (Malfunction Indicator Lamp) in order to do this.

I bought an ELM327 Multi-protocol Diagnostics Interface on eBay for about $20 that uses a computer running freeware (OBDII Scantool) in order to accomplish this. The software also has some real-time analytical tools that can be quite useful.

The only drawback was waiting for two weeks for the package to be shipped from China. You can get one of these from a US based distributor but it will cost more $.

Make sure your current scan tool does not have the ability to clear your MIL before buying something new, however.

Here's a pic of a generic OBDII Diagnostics Interface (Using a clone ELM327 chip) :

 

Sorry to have to say so in an open forum, but that is an incorrect wives-tale that has made the rounds. The ABS module does not store the VIN number, nor does it compare anything with the PCM. I and other have changed our PCMs and have not had any ABS issues.

 

This happened to me just the other day. It turned out that corrosion from my battery over time dripped down onto the brake line between the proportioning valve and the ABS valve. Remove the 2 screws holding the curved plate under the driver's headlight, and pull the plate out. Then remove the 4 bolts holding the horn mounting plate and move the plate out of the way. This now gives you a nice view of the brake lines and valves under the battery.

 

Ok, So what would I be looking for? Corrosion of the valves and whatnot, or the lines? I haven't noticed any diminished braking power nor loss of fluid. I'm not sure I understand the process there. Can a little corrosion cause the ABS and brake lights to come on? Or is there something else in there to look for?

Does anyone know where the ABS module is located? I've heard it can get wet and the connections can corrode causing incorrect signals.

As for my scantool, to get back to that subject, mine definately does not have the capability to clear MILs. The closest it can do is check them to make sure they are working properly. I.E., it checks to make sure the bulbs work... Kinda pointless in my opinion.

 

Yes that's what you're looking for. The ABS module is located under the battery and is attached to the ABS valve.