ECU Remap/ROM/Map file editors

File and OBD cable remapping

For my external USB programmer or the USB programable ECUs please use this:
External USB connection remapping

The editor can open file from all MEMS ECU version
For known ECU files a list of valid maps are shown
If the file is not known then it will still try to load it and automatically find potential maps
If you have a new file that is not know then please send it to me and I will find the correct maps and add support

ECU Remapping general info

As part of my work on these ECUs, I have a repeatable method of finding the "tables" or "maps", this is normally a time consuming or expensive process involving having to buy a "map pack".
I have built an editor for the ECU files/maps, linked above.
Some tables are still unknown but the important ones such as fuel and timing have been found, others include idle speed setting, rev limit.

At the moment I am not planning to offer any specific "tuned" or "stage 1" calibrations, I am simply giving you the ability to either tune the ECU yourself or have someone qualified do it if not.

I suggest owners of cars with modified engines should purchase a wideband lambda sensor and controller in order to more accurately monitor the air-fuel ratio of the engine.
Most of these kits provide an "emulated" narrowband output wire which can be wired into the stock ECU (if it needs a narrowband signal). This allows the stock ECU to run normally but while providing you with a much more accurate reading of the AFR.
Otherwise you could have an additional Lambda sensor bung welded into your exhaust manifold and use a wideband sensor/controller as well as the factory narrowband sensor.

Street tuning
Using a diagnostic cable you can connect and "log" a journey in the car to see what state the fuelling is in.
As above, this will be much more accurate if using a wideband lambda controller, a narrowband lambda is not accurate enough to tune from.
This can be useful to correct major fuelling issues without having to pay for a rolling road or tuner, but will never be the same as having it properly tuned on a dyno.

MEMS 1.3 Remapping

These ECUs can be modified to allow remaps
A rewriteable chip is installed as well as modifying part of the ECU circuit board to allow the chip to be easily removed
At the moment it is not possible to use an OBD cable for programming, the chip must be physically removed from the ECU each time and written by using a USB chip programmer
I can provide a chip programmer and an adaptor for the chip to fit in the programmer

1.3 ECU modified ROM chip board and socket

MEMS 1.6 Remapping

This is work in progress, there are some technical difficulties in doing this still.

MEMS 1.9 Remapping

Updated 28th April 2022:
These ECUs are similar to the 1.6 ECUs but need more work before remaps would be possible.

MEMS 2J Remapping

ECU modification - OBD/diagnostic cable programmable
The modification includes: an expansion board fitted inside the ECU, a new rewritable chip, a brand new laser cut aluminium ECU lid. A diagnostic cable is supplied which is used for mapping changes as well as general diagnostics.
Map updates can be done "live" with the engine running, the active table cell is highlighted to help with steady state/rolling road tuning.
This is available for £300 - including the ECU modification, new lid, diagnostic/programming cable and return postage

Here is a short video of the live remapping on the 2J ECUs
It shows the initial data download from the ECU and then shows looking through a few tables.
You can see the active cell highlighting which allows you to see which table cell the ECU is currently using while the engine runs


Modified 2J ECU with additional board to allow OBD remapping

MEMS 3 Remapping

Remapping the MEMS 3 ECUs is possible without modification
Andrew Revill has done an awful lot of work already for these ECUs, you can find his website page about MEMS 3 mapping here:

MAP sensor scaling calculator - for 2J ECU only

Use this to work out MAP sensor scaling values needed when fitting a different MAP sensor to an ECU
The ECU circuitry on the input pin causes a voltage drop, this is accounted for by the multiplier setting
The voltage drop multiplier is set for MPI Mini (2J) ECUs by default
MEMS 2J Mini MPI: 0.896
MEMS 3: 0.833
TD5: 0.907

ECU sensor voltage drop multiplier:

Known kPa values vs voltage:
kPa at 0v:
kPa at 5v:
Values for ECU maps:
Add (offset):

Known ECU map values:
Add (offset):
kPa at voltage:
kPa at 0v:
kPa at 5v:

Contact: email me
Disclaimer: This website is not associated with Rover in any way. This exists because there is no support for these older cars/ECUs
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