Delco HDRC is the ecu fitted on Y17DT engine from OPEL.
It has few different versions of software and 2 types of hardware (DT and DIT). Will talk here about first type of hardware, with 256K flash and square processor.
From my research, the processor of this ECU is from 68HC11 processors family and has a wierd memory layout.
$0000 - $03FF - Internal RAM
$1000 - $105F - Internal peripherals
$1800 - $1FFF - External peripherals
$2000 - $7FFF – External RAM
$8000 - $FFFF – External EPROM
In other places i`ve found totally other informations, so use this informations carefully.

My goal is to find all routines that handles cruise control, immobilizer and a way to get an input from an ecu pin and output something on another pin (to inject custom routines and handle ecu pin states).

Before proceeding further i need confirmation that my informations are correct. I don`t have a processor dump for this ecu, if anyone has will be very helpful.
I`m not familiar with Assembly, but i`m a high level programmer, so with a little help from you i can learn how to „read” assembly code.

Anybody who can help me with this ecu can contact me here or by private message. All research result will be written down here. I can provide different types of software numbers for same hardware if needed. And a software from 208K memory version for comparison.


P.S. I know this forum is mostly about ME7, but this was my first car and i want to keep it going and make some cool stuff for it with this ecu.

Thank you,
Ionut.