I wired in an AFC2 into my evo8 recently using an AEM 3.5bar map sensor. Map sensor gets power and ground off the MPD sensor on the intake manifold and the signal wire goes to the throttle wire on the AFC.

With the engine off I see 39% on the AFC for throttle or 1.65V. At about 20-21psi of boost, Im seeing 100% throttle input is ~3.3V. When the engine is idle or engine braking, I see 0% throttle.

This map sensor reads up to 35psi of boost in range of .5V to 4.5V with the AEM (I had ems on the car, but went back to stock ecu/AFC for $ reasons). With the AFC it seems the usable range is clipped for some reason.

Am I looking at the scaling wrong, or is there some reason why the AFC is reading 100% on the throttle input when it's only seeing ~3.3V

It seems to me the AFC's 0% throttle is not = 0V and 100% throttle not = 5V.

The Map sensor is scaled as such: (abreviated info from AEM document)
0.5V = -14.7psi
1.0V = -8.5psi
1.5V = -2.2psi
2.0V = 4.1psi
2.5V = 10.3psi
3.0V = 16.6psi
3.5V = 22.8psi
4.0V = 29.1psi
4.5V = 35.3psi

Any thoughts?

 

I may be wrong, but I thought the AFC learned the range based on what it saw. So if it were connected to the TPS, you could turn the ignition on, push the gas pedal all the way down, and it would learn the proper range. That would explain what you are seeing, as it's taking your max boost and setting it as 100%.

-Paul

 

Has this been resolved?

DSM is this letting you go speed density with teh VFAc?