As an extension of my JDM AMG CE project I am embarking on the journey to "chip" an HFM ECU. I feel it deserves its own thread, so here we are!

A bit of backstory for those thus unfamiliar. I started a project car, a 1993 320CE, Japanese delivered, into which I have swapped the drivetrain from a 1996 C36. The C36 is a DAS car and needs drive authorization so just swapping over the HFM isnt a solution. Hence my need to get the 3.6 mapping into an earlier non-DAS ECU. I currently have the 3.6CE running with a 1994 E320 ECU. It fires right up and runs ok but I know it isn't reaching the 3.6's potential.

The module I'm going to chip is from the 1993 300E 2.8 donor car that has already donated a lot to the project. Comparing it with the C36 ECU they are virtually identical in layout excepting the C36 ECU has one larger SMT mosfet and its associated smt resistor where the 2.8 ECU only has the unpopulated pads.

The first step is figuring out where the mapping resides. None of the chips on the 3.6 ECU have a number that comes back as a eprom but thankfully the 2.8 ECU has a chip marked M27C1024. This comes back as a one time programmable eprom. The fact that this specific chip has a sticker with a numerical designation in each ECU was also a good indication that it contains the application specific info. Lastly exhaustive internet sleuthing turned up a hint, while not that specific chip #, that the eprom would be in the plcc44 package. With this figured out I'm confident to begin this project.

I have ordered the adapter that will allow my Wilhelm eprom reader/writer to interface with a plcc44 package chip. I have ordered plcc44 sockets since I do not intend to solder the chips back in place. I will install a socket on the board to allow easy swapping of chips. Lastly I have ordered in a handfull of M28F102 chips which should be a reprogrammable drop in replacement for the M27C1024.

My first step will be to pull the eprom from both ECUs. Removal should be straight forward with a hot air station. There is a lot of room around the chip so no big worry about damaging nearby components.

Attached Thumbnails

     

__________________

90 300TE 4-M
Turbo 103, T3/T04E 50 trim
T04B cover .60 AR
Stage 3 turbine .63 AR
A2W I/C, 40 LB/HR
MS2E, 60-2 Direct Coil Control
3" Exh, AEM W/B O2
Underdrive Alt. and P/S Pulleys,
Vented Rear Discs, .034 Booster.
3.07 diffs 1st Gear Start

90 300CE 104.980
Milled & ported head, 10.3:1 compression
197° intake cam w/20° advancer
Tuned CIS ECU
4° ignition advance
PCS TCM2000, built 722.6
600W networked suction fan
Sportline sway bars
V8 rear subframe, Quaife ATB 3.06 diff