That post was Spanish dude.

So, the P0505 popped up with it unplugged finally. Good, I guess.

I plugged in another IACV that tested good (ohms test on motor) without connecting it, and the same issue came back (fluctuating RPM). I didn't expect that.

This tells me that the engine is looking for a specific response in RPM change when it actuates the IACV, and it goes all funky if it doesn't see it.

There is another component to the IACV, the actual 'butterfly' type shaft that it seems to turn when it actuates. I'm betting it likes to seize up due to steel on aluminum corrosion.

and if that butterfly is seizing up, then the motor is trying to move with something in it's way, which could cause it to overheat or draw excess amps.


An idea. A new one.

 

Brainnnnnnnnsssassss! High current draw

 

Where do I purchase this driver, CJ?

 

What driver?

 

Sta509a

 

Digikey.com,mcmelectronics.com and parts express.com also ebay has them cheap and mouser

 

Thanks bro!

 

Can you get some shots of the burnt chip and the area around it and the bottom of the board?i looked theu a few post and picks from other people before and it looks like a dual failure event a overheat and short.

 

Blew my WBO2 fuse., and DigiKey hooked it up. 0.37 cent fuses and 3$ shipping

 

Therm fuse?

 

Tuner how about benching the unit and doing a amp draw test on the motor?maby its giving a high draw at a certain position when its loading up.

 

Nmex your spot go on a IT lockdown?

 

Nah, I don't think so.

No idea what type of fuse, googled my WB, homes on some other forum had a PN so I ordered it.

Car was dead so I needed a boost, heard a pop, and now it's dead, hopefully that's the issue. Damn 350$ WB FTMFL.

 

Yeah i caint wait to see how the max acts after sitting for 11 months not being started

 

Might be a possible test, good idea.

One thing I'm not currently understanding is this...



TERMINALS #2 AND #5 = BATTERY VOLTAGE

I'm assuming, this means the ECM supplies ground return paths through Terminals 1, 3, 4, 6 from the IACV. This allows current flow and the motor actuates.

From what I see though, every coil operates on Battery Voltage at all times, does this sound correct?


If that is the case, then I can do as you say, and easily mimic the operation of this motor on the bench, while monitoring current flow through each coil.

Then I'll monitor current flow through each coil with it fully installed in an IACV housing that includes the butterfly valve shenanigans, and see what the difference is.

 

Yes, battery voltage is common to the center taps, and the ECU turns on/off the four STA509A mosfets depending on which direction (cw/ccw) it wants to step the motor.


Battery voltage is present on the center tap all the time but current only flows when the mosfet in the coil path is turned on, and I believe this arrangement has 4 (repeating) states so that only 2 mosfets are ever on at a time (but never one, three or four).


If you've already tested 2 different IACV's in your car and they both do the same thing, then it seems unlikely you have an IACV problem, right? I was thinking maybe the pindle on your IACV was gunked up, but again, if 2 different IACV's do the same thing, then this isn't likely the problem. It seems the problem would be something other than the IACV, most likely an ECU issue, or the TPS not set correctly.

 

Thanks for the info dude!

I've only replaced the Motor, not the entire assembly. The entire assembly includes the valve that the motor actually acts upon, which I'm going to pull apart and check, I think it could be corroding and seizing causing issues.

I do not think there is anything wrong with either one of the IACV motors themselves. I'd wager to say the Driving circuit is fine also, but can't say that for sure at this point.