Can I use an external MAP sensor?

[Grant]

Hi folks,

I'm installing a VEMS with new firmware and new vemstune to replace an AEM EMS-4 on a 16V ITB ae86.  The EMS-4 came on a customer car and was a huge waste of time.  I wish I pulled it much sooner.

Anyways, I have the VEMS installed and am wondering how I can get the AEM MAP sensor (Bosch Style, 3.5 BAR, 0-5V) to work with the VEMS?  I do not wish to use the internal MAP as it would make the project less tidy.  It is alread plummed for the AEM Map sensor. 

http://www.aemelectronics.com/files/info/30-2130-50.pdf

I have the MAP sensor input wired to Stepper 6 on EC18 Connector (labeled MAP In on connector diagram). 

But the ECU does not seem to be responding and I did not see where to configure the external map on VEMS tune?

Thanks in advance for any help!

[gunni]

Since you have an internal one already you will need to remove it and put a short wire between the input you are using.

I´m sure you can see one of the analog channels change when you alter the pressure in the map sensor. The problem is that the voltage simply isn´t going from the map sensor input you have selected to the map sensor input channel inside the ecu.

This might be helpful
http://www.vems.hu/files/genboardv3/assembly/vems_v3_documentation.pdf

[Grant]

Thanks for the quick response!

I actually don't have an internal map sensor installed.  Do I just run a small wire from stepper channel 6 to the map sensor voltage input on the board (Light GREEN according to VEMS Test document above)?  Do you know if I have to do any other configuring in the software?

Thanks again,
Grant

[VEMS]

Hello Grant,

Running the green wire from ecu map sensor signal pin to econoseal18-pin#6 (not stepper channel) should get you sorted, but if you ordered the ecu pre-assembled without internal map sensor this should already be set up for you. Of course the sensor will need to be calibrated in tuning software in base setup->ecu calibration.

Best regards, Dave