<h2>Dump the flash from your 32 bit GM PCM.</h2>
<p>
This article describes how to make a simple modification to your 68332 based
GM computer to allow you to dump and reprogram the flash.  It operates using
the BDM port that is built into every Motorola 68332 processor.  The BDM port is
normally used during software development to allow the programmer to single step through
the code, set breakpoints, examine memory, etc.  The BDM port has complete
access to the CPU and everything connected to it.  In this case that means it
can read the contents of the flash, and also reprogram it.
<p>
This method of dumping and reflashing does not use the DLC (OBD2 connector), and
does not require any scan tools or other OEM type hardware.  The article is divided into
2 parts.
<ul>
<li>Part 1 describes the modifications to your PCM.  9 wires have to be attached
to vias that already exist on the PCB, and a 5x2 male header has to be hot
glued to the board.
<li>
Part 2 describes a particular set of hardware and software that I used to dump
and reflash my computer.  Part 2 is optional, once the steps in Part 1 are
complete you can choose to use a commercial BDM product.  A google search should
turn up plenty of these.  Or you can build the hardware described in Part 2, and
use the software provided.  You can even write your own software using the driver
and library provided.
</ul>
<strong>
Nothing in this article, properly implemented, will affect your PCMs operation.
However, modifying the flash can leave your PCM (and vehicle) inoperative, or worse.
These changes have not been tested in a vehicle, only on a workbench.
Please be careful if you decide to make these changes on a PCM used in a vehicle.
</strong>
<p>
<a href="part1.html">Part 1</a>:  Modifying your PCM<br>
<a href="part2.html">Part 2</a>:  BDM hardware and software<br>

Written by Steve Ravet (<a href="mailto:steve.ravet@arm.com">steve.ravet@arm.com</a>)