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aem 5 bar problem

Posted: Mon Mar 02, 2009 11:25 am
by D@nny
Since I updated my software whenever I downshift or the motor pulls heavy vacuum the ecu throws a code for the map sensor and wont rev. cycle the key and it drives fine until it happens again. aem 5 bar map sensor. was something changed in the update 1.4 because it ran fine before. do you guys have a new scalar and offset for this sensor?

Posted: Tue Mar 03, 2009 9:21 am
by D@nny
I looked at your scalar anf offset equation- for aem 5 bar

min voltage and pressure is .5 volts = -1013 mbar

max voltage and pressure = 4.5 = 4157.5 mbar

range 4.0 volts

pressure range = 3144

so the scalar and off set should be 786 and -393

but this gives incorrect pressure readings -voltage so it is incorrect. any advice?

Posted: Tue Mar 03, 2009 9:33 am
by D@nny
figuring the sensor gives 18.723 psi per volt then the scalar would be 1290mbar 1290 multiplied by.5 volts would be -645 offset and then the numbers are correct.

Posted: Thu Mar 05, 2009 7:45 pm
by V-Spec race development
I have the same issue w/ this 5 bar map. Why can hondata just answer this type of questions instead of giving you puzzles.

Posted: Fri Mar 06, 2009 10:11 am
by Hondata
We provide the means to calculate the scalar and offset for any MAP sensor. See the help file
According to the information for the AEM 5 bar the scalar and offset is 1289 and -639.

However, if you're having problems as described then it could be an issue other than using the correct scalar and offset.

Posted: Fri Mar 06, 2009 10:20 am
by cranny
if it ran fine and all he did was update Smanager , than i think its safe to assume its a software issue. but , cooincidental car problems are far from unheard of for sure.

Posted: Sat Mar 07, 2009 5:35 am
by boostedcivicsir
d@nny, fwiw, i had an issue where the map would peg 65psi positive pressure when cycling the key, you may have the opposite effect, mine was a bad pin in the pigtail. may or may not be your issue but it may be worth looking at.

also i found the map is more stable and accurate when not mounted to the engine. mine is now in an a-del clamp bolted to the firewall.