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Hello everyone, i have a 2000 Maxima that sat for 2 months during the pandemic and I recently started to drive again. I noticed a few weeks ago that it was idling pretty high around 12-1500 rpm. I checked the codes today and got a lot of codes thrown at me. I changed the spark plugs and cleaned the throttle body. Well, during the throttle cleaning, I accidentally disconnected a vacuum hose that I can not find where it is supposed to connect. Any thoughts on this?
Make matters worse, it still idles high and now pulsates up to 1700rpm every 2-3 seconds. Im assuming this hose has something to do with it.
Last edited by Elijah Ajayi; 09-30-2020 at 08:29 PM.
Get the car warmed up, turn everything off (no electrical load) unplug the brown connector on the throttle position switch, go inside and turn on the AC. Not the heater, AC. The idle should drop. Go back and lock in the idle by connecting the brown connector again.
Replace vehicle speed sensor. They're not very expensive. You can find one on eBay for $20.
After all of that, get your ecu reflashed and then have them do idle air relearn.
All in all you're looking about $120 depending how much the Nissan mechanics charge you for the consult II work. Could be less.
misfire is usually because of the coil and not the spark plug. Try and narrow it down to which coils need changing because doing all 6 with quality coils is butt rape money wise.
Ecu failure is more or less catastrophic and super rare, no? As if car won't start or randomly shutting off. How do you figure your ecu failed if you have a P0505? I mean I had that code when I bought the car, I just found a way to drop the idle without replacing anything but considering everything I've read here my ecu would've failed as well.
Ecu failure is more or less catastrophic and super rare, no? As if car won't start or randomly shutting off. How do you figure your ecu failed if you have a P0505? I mean I had that code when I bought the car, I just found a way to drop the idle without replacing anything but considering everything I've read here my ecu would've failed as well.
ECU itself doesn't fail, but the component controlling iacv does.
ECU itself doesn't fail, but the component controlling iacv does.
I haven't popped open my ecu but considering everything my idle shouldn't be at 700+ while in park and definitely not 650+ when in drive. I never replaced the chip OR the iacv.
P0505 could be you just need to do idle re-learn, because you messed with TB
When you have your ignition on, IACV will cycle and you could hear the stepper motor clicking. If you don't hear it then your ECU might be fried (or other electrical connection issue). Make sure you get new IACV before putting the new reworked/fixed ECU in place again. IF you have damage IACV, you will fry your ECU again (the bad IACV is usually shorted, then it would send too much current thru the ECU and fry it).
I've seen pictures of fried ecus on here but how can an iacv short the ecu if there are things like fuses and relays to keep that from happening? I honestly don't buy it... I fixed my p0505 the way I described above and haven't had that code come up since. My idle's within spec and everything's fine, I just have the 1440 code now. The p0505 was either Nissan's cash grab or a glitch with the ecu or sensors, something that was probably addressed with the last ecu update most likely.
if what I did didn't fix my ecu but fried it some more, I probably wouldn't be able to connect any diagnostic tool to the obdii port.
I've seen pictures of fried ecus on here but how can an iacv short the ecu if there are things like fuses and relays to keep that from happening? I honestly don't buy it... I fixed my p0505 the way I described above and haven't had that code come up since. My idle's within spec and everything's fine, I just have the 1440 code now. The p0505 was either Nissan's cash grab or a glitch with the ecu or sensors, something that was probably addressed with the last ecu update most likely.
if what I did didn't fix my ecu but fried it some more, I probably wouldn't be able to connect any diagnostic tool to the obdii port.
What fuses and what relays? It's connected directly to the ECU lol. And I'm sure A to fry is low.
It may not fry immediately, but it doesn't take long. OR your iacv was just bad. Anytime idle is high, it's going to throw the code. If it's stuck open or failed open....then, yeah, ecu won't be fried.
Last edited by Child_uv_KoRn; 10-01-2020 at 10:27 PM.
What fuses and what relays? It's connected directly to the ECU lol.
**** if I know, man. I just assumed basic and fragile electric components, also the most expensive ones, are at least protected by *something*. You mean to tell me that a very expensive part of the tb, that has coolant running through it for some weird reason despite liquid not being very good for electronics to begin with, can short so bad that it fries the ecu? It doesn't make sense. I think it's much simpler than that. Maybe an ecu does fry because of the Iacv, but I think considering how rare it is there are some other conditions that have to be met, as well?
**** if I know, man. I just assumed basic and fragile electric components, also the most expensive ones, are at least protected by *something*. You mean to tell me that a very expensive part of the tb, that has coolant running through it for some weird reason despite liquid not being very good for electronics to begin with, can short so bad that it fries the ecu? It doesn't make sense. I think it's much simpler than that. Maybe an ecu does fry because of the Iacv, but I think considering how rare it is there are some other conditions that have to be met, as well?
It's not rare. It happens to every single de-k made. The first thing anyone on the forum does when buying a de-k is bypass the coolant, then unplug engine mounts lol
Last edited by Child_uv_KoRn; 10-01-2020 at 11:59 PM.
I basically did all of that but then turned on my ac while the connector was unplugged. The idle dropped right then and there, plugged the tps back in and it stuck. I've had the battery removed like 20 since then and it's still idling within spec. And the p0505 disappeared permanently.
09-30-2020, 08:20 PM
