bugeye41510

iTrader: (1)

My car sat for 3 days when I go turn it on the idle is higher then usual. Then the CEL comes on I pull the code P0519 i've cleaned the valve thoroughly. The idle now is 1500rpms... any ideas, I've also checked for any vacume leaks.

bugeye41510

iTrader: (1)

Anyone

bugeye41510

iTrader: (1)

esousa22

iTrader: (10)

did you have any prior problems? What have you done to the car, what is P0159 exactly so people dont have to put any effort in research to help you out

strider327

iTrader: (10)

Try cleaning the "Idle Air Control Valve" if that doesn't work it might be screwed. Just replace it.

DabiDa

iTrader: (6)

I know its a dumb question but need to rule it out,Did you let the car warm up? Or simply turn it on and it was at 1500k rpm? When you start the car it will go through phases of rpm levels.

bugeye41510

iTrader: (1)

The car was running fine there was no problems, the sensor is new and purchased from Subaru not more than a year ago. There was another code that I pulled it was p0508. I haven't drove the car for a couple days prior to this. When I turn on the car I do little warm up I don't hit the gas pedal until its warm, at cold start is about 2200 RPM's.

bugeye41510

iTrader: (1)

Morning bump

DaltonSR20DET

iTrader: (4)

I'm having the exact same problem... Drove my car on Friday night, the 23rd, and the next night on the 24th, during warm up, it idles at 2000rpm. After it's warm it goes to about 2000-2200rpm and then the CEL comes on and it starts to fluctuate from 1000-1500 and the exhaust sounds different. Code I got was P0519 (Idle Control System Malfunction).

I bought a new IACV gasket from Subaru Walnut Creek ($15) and cleaned out the IACV with CARB/Throttle body Cleaner, I took the tmic off and cleaned the throttle body, checked for vacuum leaks, cracks in hoses and then reset the ECU. Started back up and same thing, code p0519 came back after warm up was done.

I unplugged the IACV and ran it to see what would happen and it threw a code P0508 (Idle control system circuit low input) and P0108 (Manifold Absolute Pressure/Barometric Pressure Circuit High Input ) along with the same p0519.

Did the same thing with MAF unplugged and got P0102 (Mass Air Flow (MAF) Circuit Low Input) and P0113 (Intake Air Temperature Circuit High Input) along with the same P0519.

Next I am going to take the IACV off again and do the full cleaning (My IACV cleaning writeup - NASIOC) removing the solenoid cover and cleaning inside that. Its gotta be the IACV, Neutral Position Safety Switch on the tranny or some vacuum leak I am failing to find.

I will report my findings as I go, its dark and raining outside and I have no garage to work in. Tomorrow it is.

bugeye41510

iTrader: (1)

good 411,
i tried trouble shooting my self as well. i read on another forum and found that maybe the MAF may have been dirty or as you stated, Neutral Position Safety Switch. I've cleaned the MAF and no success next i disconnected the MAF and the car turns off (i know that normal) i turn the car back on and idles high the same CEL code turns out to be the MAF BUT! no p0519?! i reconnect it and p0519 comes back. i came to the conclusion that the MAF has gone bad and need to be replaced. Maybe its not able to read the correct amounts of air coming from the intake causing the IACV go crazy hence p0519... the code for the IACV only pops up when the MAF is disconnected.

02RS25

iTrader: (9)

i had the exact same problem. a good cleaning of the IACV and TB seemed to do the trick. Cleaned them, cleaned electrical connection at IACV, cleared code and never had a problem since... your car just hates you. LOL but ya, if a through cleaning dont do it, take a DVOM and read each terminal at connector to see what the reading are, if any.

GL

DaltonSR20DET

iTrader: (4)

Replaced my IACV with another, with same result! BUT i think I've got mine tracked down.... Driving on the freeway, I shift into neutral and let it coast around 50 MPH, turn on the cruise control, rev about 2500-3000rpm and SET the cruise... the CC will start to open the throttle body even in Neutral Position and the RPM's will climb until I step on the clutch pedal to or use the CC stalk to disengage the CC. So, in my case, the car doesn't ever know its in Neutral. Changing the Neutral Sensor Switch tomorrow.

bugeye41510

iTrader: (1)

Have you already changd the neutral position sensor, I read on another forum and they have the exact same problem and as well they've replaced that sensor. Curious to hear your results.

http://www.wrxtuners.com/forums/f72/...e-p0519-26301/

DaltonSR20DET

iTrader: (4)

Soooo, I have replaced the IACV and Neutral Sensor. I am still having the same results! I did test the new sensor with a multimeter and shows up working fine. However I can STILL put the car in cruise control when tranny is in neutral and me rolling down the street (35mph). With same result, ECU tries to rev the motor higher to keep speed at 35mph but since car is just coasting losing speed, I have to cancel CC or step on the clutch pedal before it just bounces off the rev limiter. I now suspect that there might be a break in the signal from the neutral sensor to the ECU. Again, will update as I go... takes a while since I barely have time to work on it...(usually in the dark) and I drive this car the least so I'm in no hurry lol.

DaltonSR20DET

iTrader: (4)

***resolved***
Finally got some more time to tinker with the car. I hooked up my Tactrix 1.3 cable up and ran it through Romraider logger, Free SSM, and ECUExplorer checking values/voltages on all the sensors they can see to make sure the ECU is seeing them and they are functional. Everything seemed fine. At the very end.... it all goes back cleaning the IACV!!!! Even the one I bought off a member needed to be cleaned. First attempt of cleaning was just using qtips and carb cleaner. Second attempt was actually removing the motor (the black part) and cleaning it more with carb cleaner. Third attempt cleaning was same thing but using other things like alcohol and WD40. Then I bought another used IACV and did the same steps. Trying different things like using my original valve but with the newer motor, and vice versa. The valve seemed like it spun pretty easy but pretty easy is not good enough! It really HAS to be free spinning where you practically feel zero friction. This is what worked.... i dunked the whole valve in gasoline and let it sit for a day. I pulled it up and kept spinning it with my hand going back a fourth until it just started to loosen up more and more til it just spins really freely where you can actually just blow on it and itll move the valve.