Hey guys, trying to keep this 'ol girl alive. Currently has 167k miles, returned from service last week: new power steering pump (6mos backorder), and radiator.

Now time to tackle some lingering codes:

C0276 (TCCM performance), C0240 PCM - traction control not allowed, P0300 (multiple misfires), P0304 (Cylinder 4 misfire)

Symptoms: Drove perfect before light came back on, once CE appears there is a rough idle. This is a manual tranny, in 1st and 2nd (during takeoff) it wants to bog for a few seconds, then it takes off like normal. Problems seem to reduce once engine temps warm. It's been 10deg here every morning.

In the past - I have woke up to a cold morning and had every dash light going off ---- ABS, Traction control, reduced power, etc. --- removed and cleaned the body ground and it all cleared up.

What's been done: Had received new set of iridium plugs in Sept., then cylinder 4 started appearing. Figured I had a bad plug, so I first swapped coil 1 and 4 to test coil. No change, cylinder 4 code re-appeared, so I swapped a new set of Iridium's yesterday. Cylinder 4 plug appeared to have a tad more tarnish than the others. Also installed a new battery yesterday, and added heat fuel additive. Recently cleaned MAF and throttle body, I do this as part of the car's annual maintenance as this has a K&N (like to keep those codes from kicking)

Anyone ever seen these codes in conjunction or have an idea where to start?

(*EDIT* title is incorrect, fat fingered the P0277.)

 

C0276 & C0240, good thing is, you have the TCCM, PCM, & BCM actively communicating with each other.
P0300 & P0304, sticking valve #4. Throw the K&N to the curb and clean fuel/air delivery until that misfire goes away.

 

Been running the K&N since 2011, so don't exactly have the stock airbox laying around anymore!

What's best way to cleanup the air/fuel delivery as is?

Being that this is an '06, 3.5L L52, I am also very interested in knowing where my VIN lands me for possible recalls. Production date 11.05.2005. Any help on where to check my VIN would be appreciated.

 

Before throwing anymore parts at the old girl imho, this is a good time to step back and begin a logical testing regimen.

1) test each injector for proper pulse and signal
2) test to make certain each cop is getting proper signal
3) test for cam, crank timing and proper clean signal from each
4) leak down test/ compression

I also highly recommend looking at Colorado 3.5 stuff to. They cover a lot of this kinda of stuff.

 

Here is THE list: Acts like it wants to stall/rough idle -No CEL -What To Do:

 

Ohhh I am familiar.

 

Thank you for all the responses. From this list, #3: few months ago I was getting the P0304 and replaced the cam position sensor. However did not inspect the crank position sensor or cam solenoid. I'll take a look at it whilst I run through this list.

In regards to cleaning -- would seafoam fowl up these new plugs? I am due up for an oil change and have never run seafoam through a vehicle. It's been in the back of my mind for the Hummdinger.

 

Here you go. BTW, did you pull the tccm(#2) and check/clean contacts?

PIP5029H

 

🙏 Thank you Hummerz

 

Quick update: as stated in my original message, I had a question regarding my VIN#

Had a compression/leakdown test and cylinder 4 is registering 50-psi

Also had loose intake manifold.

This vehicle needs a new head / valve repair. GM is saying there is no recall / no bulletin, so they are unwilling to assist in the repair.
I had it diagnosed by Plains Tire and GM is requesting that it get re-diagnosed by my local GM service center.

Last six of my vin# 102629