RomRaider

Hi,

I'm trying to understand how the DBW works 2010 WRX STI (JDM), and possibly diagnose a low throttle position blip/hesitation issue.

Does the duty cycle for the motor being other that 0 - mean its trying to move the throttle plate?
so -20 would be trying to close it, and +20 would be trying to open it then be 0 when its reached it target opening and dont move?
*Update* - in testing, this is not how it works, seem the motor duty cycle puts torque on the throttle plate, and if no duty the plate will return to closed (makes sense for safety run away throttle etc).

if that is correct, would this indicate its having issues trying to get to 0 opening? ( looks like the negative motor duty is the ecu trying to close the throttle but cant?)


I'm trying to find out why low throttle seems to hesitate/blip and I put my foot down a little etc, but wondering if its actually the DBW throttle having issues.

Does this look normal?


perhaps it just needs a good clean (did clean it a while back), I'll try that again.

Complete log attached, any information or advice would be great, I tried looking for a sti DBW log, but pretty specific thing and could'nt find one with the motor duty cycles and plate angle etc, to see what is normal vs my logs

Thanks.

Just an update for anyone else looking at how this works, I've just taken it off and had a bit of a play (and cleaned it, some crud around the edges but not heaps)

In its resting position (no motor Duty cycle) the throttle plate is spring loaded to return to be just cracked open (like a mm or two), you can turn it either way by hand(turn one way to get it fully closed or or turn it the other way to open it wider), this is like applying the torque the motor usually does, if you let it go, it will return to the static slightly cracked open position, the ecu can close it completely, but needs to apply negative torque to get it to close full from its normally slightly open, or positive torque to open it further than its static position, while open it can apply negative torque to close it quicker as well, so for it to be anywhere out of its static position the ecu need to be applying Duty Cycle to the motor - and just enough to hold it in the angle position its trying to achieve.

Will report back if cleaning it helps the issue I'm trying to track down.