GEMS - General Engine Management Systems Ltd - Forum

Hi,

I'm hoping someone can help. I have a Group A Evo 3 with the G2.41 board. I am wondering what outputs it can send to a logger? I have a piece of datalogging software I'm trialing which can currently take a number of inputs (OBD, CAN). What form does (or can?) the ECU send out data in?

I have seen some cars running the external GEMs display, is this a GEMs-specific format or a generic one that can be read by other devices?

Any help much appreciated!

Cheers,
Graeme.

Data logging info for EVO 1-7 can be found on pin B12 I believe. The format is as follows:-

LOGGING DATA STREAM
1 HEADER $55
2 Engine Speed ERPM 50 rpm/bit
3 LOAD LOAD 0–208
4 Throttle TPSVAR 0–208
5 Air Temp ATEMP signed degree/bit
6 Coolant CTEMP signed degree/bit
7 Battery BATT1 0 to16 Volt
8 Vehicle speed VSS km/Hr/bit
9 Oxygen raw OXAD 0 to 1.66 Volt
10 Knock raw KNKRAW 0 to 5 Volt
11 Error ERROR bit encoded
12 check sum

Data transmitted every 4.1mS at 9600Baud 2 stop bits no valid parity.

I hope that this of some help.
Regards,
RickS

Hi Rick,

Hugely appreciated, one more quick one, is the Air Temp outside air temp or intake temp? I was hoping to grab an intake temp for the logging as well, just wondering if I have to grab another sensor or if there is something I can extract from the GEMs.

Cheers!
Graeme.

Hi again Graham,
Air temperature (Air temp) is measured using a sensor mounted in the intake manifold unless your model has been altered.
The sensor should be a negative coefficient thermistor in an automotive compatible package. It may also be used to convert the inlet air velocity into a mass airflow.
BR
RickS

Many thanks for the info. I think it may be some work but I'm interested to try. The added complication is I will need to transfer the data wirelessly or by Bluetooth!

Have fun!
Regarding the display query, those display units that are configurable, can be tailored with software available for download off our website. There are, of course, some older display units that aren't, so it does depend on the model that you've seen. Input can be from stand-alone sensors and scaled within the unit or from CAN.
Regards,
RickS