ECU Details
Overview of the VR-4 ECU
Lorem Ipsum, blah blah blah.
| Item | Details | Notes |
|---|---|---|
| CPU Architecture | H8 | The H8 is patterned after the venerable PDP-11 processor architecture. This is only "interesting" for old hardware nerds. |
| Flash memory/ROM size | 128KB | This is the entirety of the code required to operate the ECU, including the executable code (the software) as well as the fuel and ignition maps. |
| Processor speed | ||
| RAM |
Can all variants be flashed with a custom ROM?
One for Bill....
Why are these ECUs still functional?
For the same age and time period, the VR-4 ECU has proven to be extremely reliable, and many 20+ year old boards are still functioning well. In comparison, ECUs of similar vintage from Toyota and other manufacturers are known to suffer from failures due to capacitors leaking. There are no hard rules on when old circuit boards or chips fail, but it is likely that Mitsubishi chose well in regards to CPU and other chips, as well as high quality capacitors.
ECU Variants
Over the production life of the VR-4 ECU, there were some updates to the hardware which impacted the ability to flash the ROM.
| Mitsubishi Part Code | Processor Type | Circuit Board ID | Notes |
|---|---|---|---|
| MD340289 | MH7201FS | JE331B132C | |
| MD340288 | MH7202F | JE331B154C | |
| MD362895 | MH7202F | JE331B154D | |
| MR578135 | MH7203FA | JE331B33802B |