so....i was like 120 miles out in the middle of the desert shooting with some buddies. on the way back the truck kept dying, it wouldnt idle at all and it wouldnt stay on unless i kept my foot on the gas.

long story short, it threw codes p0508/p0509 idle air control circuit high/low. dropped it off at the dealer since i have an extended warranty to 150k

they said they replaced the idle air control motor and that the throttle body is really dirty, i need new spark plugs, i need a pcm update for the idle control and i need to run some fuel cleaner through the gas tank

i said cool ill take care of the throttle body and spark plugs (didnt want to pay over 200 bucks for those, wtf?) but i need to get the pcm update for $110 (wtf!)

i went to bakersfield the next day for work and while i was out there the truck just died again and threw a check engine light (im assuming it was the same codes) i let my truck sit for liek 10 minutes and started it back up and it seemed fine but the light was still there. i called the dealership and the guy gets all lippy with me saying 'i told u that u needed to clean out the throttle body its REALLY dirty, and u need plugs' im like da fuq? ive never cleaned the throttle body on any of my cars/trucks and had problems like this. anyways the following day (still in bakersfield) i finished my work and was about to head home and the dang check engine light cleared itself (wtf again)

so i make it all the way home and i cleaned the f out of my throttle body yesterday (didnt seem very dirty), poured some lucas fuel injector cleaner through it and i will be replacing the spark plugs tonight.

i did some research on the codes and some people reported they had to get the iac wiring harness replaced and some other people reported they ended up having to get their pcm replaced. anyone have these issues before? if so how did you resolve or get the mechanic to replace more stuff?

this is becoming worrysome for me as i am at 120k miles and my warranty expires at 150k, i also need this truck to be reliable for many years to come as i use it as a daily driver for service calls (im a field tech)

 

What was the outcome after cleaning the throttle body? Did you actually remove the throttle body and take off the IAC to clean out the IAC passageway also, or simply clean around the throttle valve/seat (which would be insignificant for idle performance)?

Both my IAC and the tiny passageway seem to get gummed up pretty well even after only about 30k, and the IAC doesn't have much travel to adjust for it, so it seems reasonable that at 120k your engine is probably choking for air at idle if that passageway was never cleaned properly.

With regard to plugs, mine actually gain about .010" in gap after only 36k. At 120k, if never changed, who knows what gaps your plugs are running...

The PCM update for idle control...The way I see it, if it idled fine in the past (before being dirtied up), then the parameters shouldn't be a problem. Just another money-maker for them.

Sounds like a can of CRC throttle body cleaner (done right) and some new oem NGK plugs should do wonders for your truck.

 

the plugs have been changed 2 times in 50k miles. i took the throttle body and all sensors completely off and cleaned every orifice of that thing, but like i said it wasnt very dirty to begin with. i changed the plugs when i first got the truck at 80k, then about 30k after.

well my truck has always idled rough and i would get an occasional sputtering when sitting...idle, like the rpms would drop up and down and the engine would shake real bad but then go back to normal after a few seconds but it would never throw a code so noone wanted to try and diagnose it. now that i finally throw a code after the engine is actually taking a crap on me and they want to blame it on worn plugs and a dirty throttle body...come on wtf, it just seems like they dont want to burn time and money on it.

 

also like i said before it is idling like normal now and the light went away on its own (before the cleaning). it idles rough like it always has, a little shaking every now and then.

 

Ok, sounds like you're good to go then. Just keep up with the normal maintenance and you should be fine. I've never known my truck to be completely smooth either.

 

edited my post lol, it idles the same whether its clean or not

 

If it's not idling properly and it's still under warranty, I'd take it back & have that fixed before the last 30K miles are used up and you're left holding the bag.

 

That's weird. I bought my used truck from a Dodge dealer and got a 2 yr extended warranty. When the check engine came on for the camshaft sensor I'm pretty sure they updated the PCM as well. Only thing I was charged was for the deductible. I don't understand why that wouldn't be covered under warranty as that's not maintenance.

I've seen some independent shops say they can do the updates as well... could see how much those run or see if they can throw it under your warranty.

 

it died again today on the way home from work in the middle of traffic, freakin sucked cause there was so much traffic i couldnt push it off to the right. had to push it into the beginning of the left hand turn lane. ended up waiting 2 hrs for a damn tow truck to come get me too.

btw i have a carmax extended warranty and it sux *** im coming to find out

 

Next time it craps out in the middle of the road, just leave it there and walk away, call the dealership to come and get,