hi,

as mentioned in previous post..

I got a couple CEL recently for code P0507 ( Idle Speed Control System)

the first time it came it went off on its own within the same day.
the second time it came on, the code was confirmed P0507 with my friends code reader, we erased it. my car was not showing any abnormal issues drove as normal. and I can only assyme the first time was same code, since it went off on its own.

now im getting CEL for 3rd time. didnt get a chance to go to my friend again..

so I started to do the manual diagnostic method, with the pedal.

but when I went through the steps.. the CEL started flashin before I could finish the sequence.

it flahsed 5 times and thats it.

its supposed to flash 10times fast, and then proceeds to flash to read out the numbers for the code..

I tried the sequence multiples time.. but it kept starting to flash before the steps were over, flashing ony 5 times slowly and thats it and stayed on..

whats this all about..?? this is starting to annoy me cause the car is driving fine..

 

well just like the first time.. the CEL went off on its own after a few restarts..

I was not able to get the self diagnostic sequence to work to read the code as mentioned above to see if it was the same one..

assuming it was the same P0507 code..
it seems to pop up after a few drives, and then goes off on its own after several restarts..?

this has happened now 3 times during a week and a half..

today which was the 3rd time it came.. was while I was in traffic.. literally bumper to bumper..one moment nothing, and then the next moment the CEL light was on..?

so I have no idea why this is happening.. all the while with no change to the car whatsoever..

in 7 years of ownership of my 2005 350Z, never seen this code..

 

According to the code PO507 as you say this is an idle speed control system problem. According to the code your RPM's should be running high. Are you noticing any difference when your CEL comes on? Or is the engine maintaining normal tickover RPM?
You could also try using your smartphone to record the complete procedure and then you can playback what is happening at your leisure, you never know you might be missing something the recording is picking up.

 

thanks for the feedback..

no the idle is the same, even when the CEL light is on..
it was set to 1000rpm when the car was tuned with uprev..
been riding with the vortech for over 2 years.. never seen this code.. and now its popped up 3 times..

could this have any possible relation to tire pressure.?
I recently put all four corners to 40psi cold, which means could get close to 50psi hot.
previously I had pressure at 35psi fron and 37 rear..and was told this was too low.
tire sizes: 245/35/19 Front 275/35/19 rear.

with the higher tire pressure now, could this be throwing off the 1% tire revolutions threshold..causing the ecu to think the rpms are not correct..? and this roughly coincides when I started to get this code