New guy... I have one to stump you all... P0507 and surging acceleration/throttle... Help!!

[leesharpe75]

Ok... so I have an 02 Pathfinder LE 2wd... replaced a few O2 sensors to clear codes and was left with P0507 code(idle rpms higher than should be)... read online to clean the throttle body(done), problem persists then change IAC actuator(done)... problem persists then perform IAC relearn procedure... The plot thickens!!!! Everywhere I found this procedure, even from a Nissan technician, it says that after the MIL light blinks for 10 secs it should then go to a steady glow... My vehicle does not do that!!! Instead, it blinks at 1 sec intervals for 10 blinks, then it blinks at a faster interval for 3 blinks pause then 10 blinks then goes back to the 10 one sec interval blinks and the repeats that over and over... It never goes to the steady glow like everyone says it's supposed to do! Worse yet, after getting stuck in this blinking light limbo, I get a weird surging in the acceleration on the vehicle... both in prk and on the road... at 1500rpm it pulses/surges... if I really get on the gas it clears up at 2000rpm or so. the vehicle drove great only idling fast prior to this, now it is undriveable as it bucks like a bronco unless I floor it... also this whole time that I try to drive it the "service engine soon" light is still just blinking as described about... HELP!!!

Anyone else experienced this? I've had 2 mechanics look at it and logged about 10 hours of research tie on this issue... I've read that I should unplug the IAC Brown connector(didn't work), do the ecm reset procedure(didn't work), may have a bad ecm relay(gonna check tomorrow)... weird thing is that if I give it throttle under the hood, there's no surging... I need some ideas, plz!!!

I feel like the blinking of the MIL in the set intervals is supposed to tell me something, I have yet to find anyone who can tell me what that is... I have read the majority of the service manual and have no answers either.

The ghost in the Pathfinder!!!

[Dattebayo]

Just a quick question: What's MIL?

[MinisterofDOOM]

Malfunction Indicator Lamp. Just another term for CEL, though I don't see it used as often so it threw me off the first few times I saw it, too.

To the OP: you are correct; usually those patterned flashes are a coded sequence to report a specific error. Just need to find what that particular sequence indicates.
The FSM for your car may have that info; you can find it here: http://www.nicoclub.com/archives/nissan ... nuals.html (try the "idx" or "fwd" sections to start searching)
I'll see if I can do some searching to find the code definition, too.

EDIT:
Page EC-73 says it just flashes out the OBDII DTC, but P0310 (3, then 10) is cylinder 10 misfire, so that's not correct here (unless you've swapped an LA V10 or a Ford Modular V10 or something into your Pathfinder, in which case...neat). The page doesn't specify how to read the flashes, though, so I may be misinterpreting.

Is the P0507 still the only DCT code you're getting with a code reader? The reason I ask is that if it is a P03X0 code that's being reported by your MIL/CEL, that's a single-cylinder misfire code which could be ignition coil or plug related, though I'd be inclined to agree that IAC is more likely given the P0507 code. But coils can cause weird high idle and RPM-dependent roughness so it may be worth a check. Usually coil-related roughness comes toward the end of the tach, though, rather than the middle or bottom.