Picking the Brain

I want to go over how to use the Standard Control Module (SCM) to diagnose a machine.  The SCM is called many things, the brain, the computer, the box, etc, but what we need to know is that what goes on inside is not magic, but logic.  At the core of the SCM it only understands inputs (what we do) and outputs (what the machine does).

The SCM does a lot of cool things, It controls the basic functions of the machine, handles the safety interlock, replaces relays, and shows us what is going on with the machine.  The best thing about an SCM is that you do not need any special tools to do basic system checks.  That is what those lights are for.

Procore 648 SCM

While there will be different decals on different machines, there are some things that will always be the same.  First, there there are three boxes on the decal.  One box has a red LED, this is the power light.  When ever the key is on the red light should be on. No Red LED = No power check fuses, battery etc.  

Next is the big box on the opposite side of the power light. (or everything not in a box)  These lights show us the inputs, or switches that are open or closed.  (The switches on machines with an SCM all go to ground)  Some examples of these switches are, over temp, seat, neutral, PTO, and head position switches on a Procore.  The decal has a symbol to show us what switch it matches up to. 

Last is the smaller box.  This is for the outputs, what the machine does when the correct inputs are met.  Outputs are things like solenoids.  Example, when we are in neutral, in the seat, the PTO is not engaged, and we turn the key to crank, the output light for crank will light.  

7200 SCM

Above you can see what the lights look like on a 7200.  The reason there are two lights for the temp is because this machines uses a two step shutdown.  The first light comes on and the PTO will shut off, the second light will come on and shut down the machine.  

I think the most useful situation for using the lights is in a “no start” situation.  You can easily check the safety interlock, and see if the SCM is sending the correct outputs.  

The most common machines to use the SCM are the 7200, 3500, Procore, 4500 & 4700 (years 2004-2008)

Here is where to find it-

7200 right side panel

Procore 648 SCM 

3500 SCM