Barometric compensation and MAP+IAT sensor scaling

[Dochka]

Hi,
I'm running a GEMS plug and play ecu for the Mitsubishi Lancer Evo 9 , but awaiting for the IAT sensor to arrive to start the engine...
I'm new to this ecu and would like to ask how to run barometric compensation ? I'm running a VDO 5 Bar map sensor, do i have to run another map sensor in parallel to enable barometric correction? Also how to scale this VDO 5 bar map sensor? Data?
And the GM open element IAT sensor...
Thanks a lot for the support

Sincerely
Kamal

[RickS]

At different Altitudes the air pressure varies, the air density changes and therefore less or more fuel is needed to maintain a stoichiometric air/fuel mixture. The ECU can automatically compensate for this by use of the Barometric sensor. The ECU has an in-built Baro sensor in the air-box (MAF sensor if I remember correctly) and this can be used to help compensate for changes in barometric pressure.

Once options set in the ECU are met, the Baro Fuel, Baro Ign and Baro Boost Tables set compensations depending on barometric air pressure.

HTH
RickS

[RickS]

....... and AIT scaling is accomplished by using the AIT Sensor Table, used to translate raw data into a meaningful figure, in this case °C.
RickS

[Dochka]

At different Altitudes the air pressure varies, the air density changes and therefore less or more fuel is needed to maintain a stoichiometric air/fuel mixture. The ECU can automatically compensate for this by use of the Barometric sensor. The ECU has an in-built Baro sensor in the air-box (MAF sensor if I remember correctly) and this can be used to help compensate for changes in barometric pressure.

Once options set in the ECU are met, the Baro Fuel, Baro Ign and Baro Boost Tables set compensations depending on barometric air pressure.

HTH
RickS

Hi RickS, I'm running the VDO 5bar MAP sensor, not the original MAF sensor;
How do I setup the barometric compensation function?

Regards
Kamal

[Dochka]

....... and AIT scaling is accomplished by using the AIT Sensor Table, used to translate raw data into a meaningful figure, in this case °C.
RickS

How to scale this table?
I mean I need a calibration table specific for these sensors, from where i get it?
Isn't there a saved table for those brands?
Thanks for your help

[RickS]

No Kamal,
We don't store scalar tables by manufacture of sensors. I would expect that the information that you require would be available from the sensor manufacturers themselves. Either tables or grids are then manually setup using GWv4.

With the MAP sensor disconnected from the inlet it may be scaled for use as a barometric sensor.

The raw data from the MAP sensor can be monitored and logged in parameter MAP raw. In order to set the range of the MAP sensor, the highest voltage value shown in MAP raw, when the MAP sensor is subjected to the highest possible manifold pressure, should be entered into option MAP Max. Similarly the lowest voltage value shown in MAP raw, when the MAP sensor is subjected to the lowest possible manifold pressure, should be entered into option MAP Min. This value is typically 0. MAP sensors should be linear in response, so points in between MAP Max and MAP Min are easy to determine.
The actual readings from the MAP sensor may need correcting slightly to make them entirely linear and this should be done using the MAP Sensor table to produce parameter MAP raw Lin.

Regarding the AIT query, when you view your AIT Sensor Table Graph, what values do you see on the AIT raw axis. Depending on the version of 9 that you are running, the value could be in 'bits', 'volts' or as a percentage. 0-256 bits equates to 0-5v.

HTH
RickS

[CarJerk]

Hi,
I'm running a GEMS plug and play ecu for the Mitsubishi Lancer Evo 9 , but awaiting for the IAT sensor to arrive to start the engine...
I'm new to this ecu and would like to ask how to run barometric compensation ? I'm running a VDO 5 Bar map sensor, do i have to run another map sensor in parallel to enable barometric correction? Also how to scale this VDO 5 bar map sensor? Data?
And the GM open element IAT sensor...
Thanks a lot for the support

Sincerely
Kamal

hi kamal! have you receive your iat sensor? Just want more information in regards to that. Thanks!

[RickS]

There is now an entry in the "Common Technical FAQ's" board called 'Load Scaling Examples' in the 'Engine ECUs' post.

http://www.gems.co.uk/forum/viewtopic.php?f=16&t=510

This contains some scaling info for Delco and Motorola but the info should help you apply the logic for other brands.

HTH