MaxGearhead

Bought a 2001 SE 20AE MT in January and in less than a week, the IACV failed (stopped idling). I have appreciated all the help and advice from this forum- thanks much. Unfortunately, it is still not repaired properly.
Replaced with an OEM IACV, still got the P0505 code and had a high, oscillating idle. Sent the ECU into Module Repair Pros (who where awesome and fast) and reinstalled along with doing the coolant bypass. Replaced the IACV connector as the old one melted a little when the valve failed. Idle is controlled but still idles at about 1100 RPM when warmed up and also has an jerky on/off throttle response. Tried doing the idle air relearn procedure multiple times but with no results. Am taking it to the dealer to see if they can do the relearn. Wish I had read these forums before I bought the car- might have averted this headache by doing the preventative procedures with the IACV.

Child_uv_KoRn

iTrader: (7)

Did you try cleaning it? I like to spray em out really well, then squirt a little lube in.

Also, did you unplug the battery for a while to reset ecu?

MaxGearhead

Yes, reset ECU.

MaxGearhead

Had the Nissan dealer do the idle air relearn procedure. They could only get it down to about 850 RPM. Will look for a vacuum leak next.

Whostheboog

You didn't have the new Iacv installed before having the ecu repaired did you?

MaxGearhead

I had an extra one installed before I fixed the ECU and then put the Hitachi unit in.

Whostheboog

Just making sure I understand you right. I hope you don't take it as rude. So right now you have the new Hitachi one installed along with your repaired ecu. Now just for my own assurement I ask are you positive that your new iacv (the Hitachi one you mentioned) has not been on the car with the unprepared ecu correct? Also your repaired ecu has not been installed while the older/ extra iacvs were still installed because they will both kill each other no matter which one is the good or bad. The repaired ecu will short and blow the sta509a mosfet inside the ecu. This can happen even if only briefly installed together will cause that code. If they never did come in contact and you're positive of that then I would suspect the wiring. How did you replace the connector? Butt splice, solder, or twist and tape? If you didn't solder and heat shrink I would urge you to go back and do so. Look into the sta509a mosfet, a desoldering pump, and maybe even practice removing and installing chips on an old mother board or ecu if available. Because it only kills 1 chip in your ecu...