P0340 code

[darkhorse05]

Ok guys I have searched and searched for any answer to this problem and I can find any answers, car is an 05 gt and mods are as follows: jlt series 3 intake, bbk twin 62mm throttle body, frpp shorty headers, and cat less x. I have gotten the dreaded p0340 and the p0344 codes about a month ago, so started by swapping sensors from one side to the other to see if it changed which it didn't. After some research I saw the tsb about the alternator, picked up a new one and the fixed the p0344 code but still have the p0340 and cannot get it to go away. I've deleted codes and the come right back, tried pullin tune out and putting factory program back in with no luck I need to get this fixed ASAP as I am getting ready to have to leave for work in Kansas end of next month. Any ideas to fix this? TIA

 

[scramblr]

Check the battery. The bad alternator could have damaged it or vice verse.

 

[darkhorse05]

That's the thing I have put a brand new battery too

 

[JimIII@JDM]

Had this issue on my 06 it was the alternator. If not that then I would replace your VCT housing's and Phasers. Do you get any ticking or tapping noises from the engine, especially at idle?

 

[darkhorse05]

No tapping but every once in a while I would have a slight rattle upon startup

 

[JimIII@JDM]

After installing the new alternator did you monitor voltage readings to make sure its charging properly?

 

[darkhorse05]

Yes I did and was showing 14.6

 

[05stroker]

No tapping but every once in a while I would have a slight rattle upon startup

That sounds like a can phaser. Check it out on youtube and see if it sounds like yours.

 

[darkhorse05]

Checked out the videos and no that's not it it was just a slight rattle nothing like the videos

 

[05stroker]

Checked out the videos and no that's not it it was just a slight rattle nothing like the videos

It could also be a tensioner with a blown gasket leaking down. Also one time I had this code and replaced the crank sensor and it went away for a couple months and then came back. I have fought this code for quite sometime myself. I have it again right now but think it is the fact that my battery has been setting for several months.

 

[darkhorse05]

Well the thing is that as sudden as the rattle started it stopped and I took the aftermarket time out the other evening and uploaded the factory program and it went away, then reinstalled the aftermarket tune and it can back, well re did the process the following evening and had the code in both programs

 

[05stroker]

Well the thing is that as sudden as the rattle started it stopped and I took the aftermarket time out the other evening and uploaded the factory program and it went away, then reinstalled the aftermarket tune and it can back, well re did the process the following evening and had the code in both programs

I would guess that when you clear it on either tune it will come back on every other start, without the PCM being flashed again.

 

[darkhorse05]

So in other words the pcm needs reflashed?

 

[darkhorse05]

I'm still lost on this is the bad thing

 

[darkhorse05]

Bump

 

[05stroker]

So in other words the pcm needs reflashed?

No I was referring to reloading your tune. If I was to clear the code it would come back every second start after clearing the code. I believe it was because my battery was weak and the voltage would drop below a certain level on startup thus activating the code Looks like mine may have been because my battery was not fully charged as I am not getting the code now and my alternator is putting out 14.26 volts.

 

[darkhorse05]

Hmm that's odd cause I clear mine and it comes back every second start also so it's bugging me that I can't find a solution for this

 

[darkhorse05]

And that's also with both the factory and aftermarket programs in it

 

[thump_rrr]

Your answer is the alternator but it seems like you don't want to believe it.
I've gone through 5 alternators and a wiring harness so far.
Mine has a Saleen supercharger so the alternator is flipped around backwards and rotates in the opposite direction. Due to this the alternator cannot cool itself properly and overheats.

If you are handy and have the proper tool to remove the pulley you can separate the alternator exposing the voltage regulator. You may find that the voltage regulator nuts are loose causing your issue.

 

[thump_rrr]

Your answer is the alternator but it seems like you don't want to believe it.
I've gone through 5 alternators and a wiring harness so far.
Mine has a Saleen supercharger so the alternator is flipped around backwards and rotates in the opposite direction. Due to this the alternator cannot cool itself properly and overheats.

If you are handy and have the proper tool to remove the pulley you can separate the alternator exposing the voltage regulator. You may find that the voltage regulator nuts are loose causing your issue.