need some dbw help

stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: need some dbw help

Post by stevieturbo »

SO have you actually calibrated both pedal position sensors and throttle position sensors ( blade ) throughout their movement ? ( with DBW disabled of course before you try and move it manually to calibrate TPS )

Are you saying the blade does nothing at all in relation to pedal movement ?

And don't see why you'd ever want a minimum blade position of 50% during cranking.
Replica_rs4
Posts: 19
Joined: Wed Sep 01, 2021 3:55 am

Re: need some dbw help

Post by Replica_rs4 »

I set 50 % duty cycle to see if throttle would move, to see if duty is being applied. Just a test. It has nothing to do with wanting 50 dc at crank.
Replica_rs4
Posts: 19
Joined: Wed Sep 01, 2021 3:55 am

Re: need some dbw help

Post by Replica_rs4 »

Calibrated pps and tps as per insctructions. No issues.
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: need some dbw help

Post by stevieturbo »

But setting that at 50% means that regardless of your pedal position......it's going to be at least 50% blade.

Use sensible settings, and get it to respond to your foot.

So key on, engine off....where is the blade ? And what is the position target ?
Replica_rs4
Posts: 19
Joined: Wed Sep 01, 2021 3:55 am

Re: need some dbw help

Post by Replica_rs4 »

Key on engine off. With current scal setting blade at 6 percent should be 50 percent . With no duty aplied blade will be 3.5 percent , that is its natural position . So it is trying to open , but wont .
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: need some dbw help

Post by stevieturbo »

So blade target is 50% and it will not move ?

are you logging all the control aspects to see if it is trying to do anything ?
Replica_rs4
Posts: 19
Joined: Wed Sep 01, 2021 3:55 am

Re: need some dbw help

Post by Replica_rs4 »

Yes, i cant get blade to move to set duty cycle. With dc 50% it moves 2 percent from 3.5 percent to 5.5 or 6 percent. That 2 percent is where the slack is in throtlle body where no pressure aplied by tb blade spring. I can see ecu apply pd gain and integral gain . I can feel some force being aplied to blade , i can feel more force aplied on closing . I guess its normal because of return spring . But very little force aplied to opening blade . There is deff force applied to blade trying to open it, but not enough to over come spring resistance
stevieturbo
Posts: 1321
Joined: Sun Dec 07, 2008 2:04 pm

Re: need some dbw help

Post by stevieturbo »

So if blade target is 50% and it does not move...what do the logs say ?

If you manually apply 12v/gnd to the blade motor, does it move ? ( just briefly, do not hold it there, and likewise polarity reversed )
Replica_rs4
Posts: 19
Joined: Wed Sep 01, 2021 3:55 am

Re: need some dbw help

Post by Replica_rs4 »

I can see ecu increasing pd gain and ig gain till it hit set limit for pd or ig is what i see in log . It seems as im not applying enough power to tb motor to overpower resistance of return spring on throttle blade.
Replica_rs4
Posts: 19
Joined: Wed Sep 01, 2021 3:55 am

Re: need some dbw help

Post by Replica_rs4 »

And yes. Tb works as it should if put to 12v and ground both ways closing and opening. It feels like output on dbw a2 and a3 does not match output requested by ecu . Or im not requesting enough power to open blade .
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