How to Socket the EPROM in a DSM ECU
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- Make certain you are competent. Removing the EPROM is
a lot more difficult than you might think at first. It is not
a task to be completed with solder braid and a cheap soldering iron! You can
seriously damage your ECU if you do not know what you are doing. If you don't
think you can do it yourself, perhaps you have a friend who is an electrical
engineer or a programmer and owes you a favor. Anyone who would be competent
enough to do it would know what to do after reading this document. It really
isn't that tough if you have the right equipment.
- Remove the ECU. You can follow the instructions for
EPROM checking for the first generation and
found elsewhere on this site.
- Open up the ECU. There are four screws on the outside
of the case. Be absolutely certain that you are using the
correct size Phillips screwdriver. For some reason, they put tons of torque on
some of the ECUs screws. The wrong size head will lead to stripping the screw
- Remove the circuit board. There are an additional
four screws holding the circuit board to the bottom of the ECU box. Simply
remove these screws and slide out the circuit board.
- Remove the conformal coating. You might want to
remove the conformal coating around the EPROM on both the top and the bottom
of the board. This coating prevents oxidation and protects the surface of the
board. It is plastic-like and will make a nasty smell when a soldering iron is
applied to it. Acetone should remove it quickly. Don't get any on the EPROM
label, as it might come off or lose its number stamping.
- Desolder the EPROM. It would be best to use a full
soldering station including solder sucker. The job goes quite quickly when you
have the right equipment. We recommend at least using a Weller soldering
station if you must resort to a hand-pump solder sucker and copper braid. Be
certain to remove the solder from the bottom and top of the board before
trying to pry the EPROM out - you might lift a copper pad otherwise.
- Remove the EPROM. Be very careful on
this step! Use a small screwdriver or pocket-knife to gently
pry the EPROM out. Do not apply much force. If you encounter any resistance,
stop and check for remaining solder holding the pins in. If you are not
careful here, you will pop traces!
- Cleanup. After removing the EPROM, inspect the board
pads with a magnifying glass and use an exacto blade to clean up any solder
flash on the pads. You also might want to use copper braid to soak up any
residual solder, even if you used a solder sucker previously. Also, clean off
the pins of the EPROM you just pried out.
- Install socket. We use and highly recommend the high
quality Augat gold-plated round-hole sockets (28 pins). We've never
experienced any EPROM creep even though the socket has seen about 100 in-out
cycles over five years. You could also use a ZIF (zero insertion force) socket
if you expect to be changing EPROMs quite often.
- You are done! At this point, if you like, you can
spray on some conformal coating to cover what you removed. Be careful not to
get any on the socket's metal contacts. Put the stock chip back into your new
socket, or install your upgrade chip. Screw the board back into the bottom
case and then screw the ECU cover on. Plug the ECU back into the car and you