ABS Module

What is the problem that makes the ABS module suspect? Code(s) There is a common problem with them that is not the module but a bad ground.

The ABS light and brake light both come on. it does not come on automatically when I crank my truck, but when I am driving it it does and does not go off.

The most common reason for that is a bad wheel speed sensor. You can use a good scan tool that can read ABS codes to see which one is causing the problem. If it was a failed ABS module the lights would come on as soon as you start the truck.

But it also comes on while the truck is setting still and running after it has been cranked.

Still more likely to be a sensor. A bad or broken wire will turn on the light as soon as the system runs a self test, which it does every time the key is turned on. That is why I suggest scanning it first. Nothing like replacing the ABS unit, then needing a scan tool to cycle it to bleed the system. Fighting to bleed the brakes and then still having a light because of a broken wire. With a scan and knowing the codes you do not just end up chasing the problem and spending time and money on unneeded parts.

How do you scan it and how do I get a tool to do that with?

You need a scan tool that can read ABS codes. Most of the parts stores will only scan for engine/power-train codes. My suggestion is to buy an entry level tool and use it. Having it yourself means that you can also help friends/neighbors or even family as well. Plus it would allow you to actually see what the codes are and possibly some of the live data to make servicing a vehicle easier.

These are just some examples of tools that can read OBDII/CAN/ABS and more.

Innova 3150e
Cen-Tech® - #60794
Craftsman #568590
Actron CP9580A
Actron CP9690