Mk7 GTI limp mode/P0340

Hey guys- I just completed the water pump/ thermostat housing replacement on the 2015 GTI. A bit of a process but it cleared my trouble code P0226. 
 

Now I have P0340- cam position sensor intake. Which completely wasn't touched during my repair process. And I'm in limp home. 
 

Could this be because I drove it without completely purging the coolant system? Does it auto clear after a number of cycles without the code reappearing? I reset the code and it hasn't triggered a new check engine light but the code is still stored as "permanent". 
 

any help you can give would be great. Beers on me. 

Update 1: 

battery (as mentioned in the cornflower blue gti thread) is f'ing kaput. Second one in just under six years. Hoping that is at least part of the culprit for the epc check engine light and weird code. 
apparently that code can mean not just the cam sensor but any number of things. I'll get the battery replaced and see what she shows after that. 

Yeah a weak battery can do all sorts of weird things with codes. On my mk6 gti the cam chain tensioner crapped out(very common on the mk6's) and would throw the cam position code.  

Hope it's just the battery.

If that is the TFSI engine, there is a strong chance that it's coincidentally the screen on the cam bridge has come loose and debris is fouling the spool valve.

BTDT this week on a Q5, with a side of low oil pressure because it turns out you shouldn't actually wait 10k+ miles between oil changes.  Fortunately the guy is scrapping the truck, I foresaw a huge E36 M3show developing if he wanted me to tear into it deeper.

More info today. I had a bad battery, called the VW dealer first thing. He said VW batteries have a 12 month warranty. I distinctly remember the parts lady saying it had a 48 month, but whatevs. I'm close enough that the pro-rata wouldn't have done much anyway. I was planning to punt and have them diagnose while I had the battery replaced, but the first appointment was for the 21st. Wow.  I bought a Napa Premium (84 month warranty, mofo!).  Didn't clear the code.

So I delayed all day- my son is a shop student in HS (actually just graduated today!) and I had him check the shopkey for my problem. I ran through the diagnosis process- they had the pins on the harness/ecu connection incorrect, so that was a pain in the ass to figure out. At first because of this, I feared that I'd broken/chafed the wires while fixing the water pump, but the harness is in perfect shape. So, I started checking pins for continuity one by one. There were "only" 105 on the connector, so it didn't take too long to figure out that the pins were incorrect in the shopkey program. 

So, after finding the correct pins for the position sensor wires, everything in the harness checked out, and it said "replace the camshaft position sensor". I don't 100% trust this, because it was fine before I did the (unrelated) water pump work, but I'm going with it for now. I'll be picking up a new sensor tomorrow morning and installing. I'll report back. 

Good news- if I hadn't reported earlier- was that the P0226 coolant transfer valve code cleared immediately when I powered up after the water pump/thermo housing replacement. I dig that FCP Euro has lifetime guarantee on their parts, so if this happens again, allegedly the replacement from them is free. That's some seriously good stuff. Also good, nay, it was absolutely fantastic- was their install video, which was comprehensive and very easy to follow. Also good was that they sell a kit with all the crap you need. So two major thumbs up for FCP Euro. I'll continue to buy parts from those guys.

Pete. (l33t FS) said:

If that is the TFSI engine, there is a strong chance that it's coincidentally the screen on the cam bridge has come loose and debris is fouling the spool valve.

 

BTDT this week on a Q5, with a side of low oil pressure because it turns out you shouldn't actually wait 10k+ miles between oil changes.  Fortunately the guy is scrapping the truck, I foresaw a huge E36 M3show developing if he wanted me to tear into it deeper.

Oh god I hope it isn't that. I've been doing 10k oil changes. I've been doing it with premium stuff- liqui moly. I'd better up the interval I guess. Is 5k good or do I need to move it even more?

Well no one will be surprised but the cam sensor did not fix the problem. Code is still there. Cleared code and it came back.  
 

sigh. 
 

don't really know what to do next. 

Still in limp mode?  I think you would have much better luck on a VW-specific forum.

In reply to Teh E36 M3 :

I wouldn't do 10k oil changes.  My hard and fast rule is 5k oil changes on all cars

Still in limp mode. I've searched all the VW forums that the search engines offer with zero luck. Part of my documenting this here is to have the keywords out there for the next guy. 

Side rant- an "Audi" independent shop in town that does APR installs etc- they only work on Audis. Wtf. I mean, it's their world, but it seems weird since VW's are the same exact vehicles without the four rings.  Chatted with the dude, and he was pretty hard over on it. But he doesn't mind doing the APR software install (?). So I actually broke down and booked an appointment at the VW dealer- earliest I can get in is the 21st. I'll keep after it until then, but figured I'd do that as a backstop.

Doc- yeah, I'd better get with it- figured that premium oil and filters, and following MFR guidelines would be legit. I'll go back to 5k. And probably succumb to E-cars from here on out.

Well, "limp mode" was your esteemed author missing a clamp on- wait for it- an intercooler hose. Jesus H. So all the power is back. Which is good. But the code is still on. I'm now hoping that it just clears itself through a few drive cycles. 

I had thought it might be a bubble in the cooling system- so I bought maybe the coolest tool ever for the job of refilling coolant. UView vacuum coolant fill. It was about $120, but I figured I'll be doing four cars, and if it fixed my problem it would be well worth it. So the system works by plugging the unit into your overflow tank, then attaching your air hose to an eductor that draws a huge (24-26") vacuum on your cooling system, then you shut a valve, attach another hose to your bottle of coolant, then open the valve, and voila. No bubbles. No bullE36 M3 burping. I fully endorse the thing. I think there is a cheaper version of what I got, but mine is all brass, which makes me happy.  Didn't fix the problem, but I don't feel bad about the purchase. It will save a ton of time in the future. 

Onward and upward. I feel like a huge moron for the intercooler hose, because I swear I double checked everything, but I'd probably just put the hose on the intercooler and forgot to tighten. Sigh. Still have the code, and I'll be working on it some more tomorrow.

In reply to Teh E36 M3 :

Congrats on finding it. 

yeah, so far I just found the hose that my stupid ass missed. Error code still present.

In reply to Teh E36 M3 :

Sounds like the Air Lift tool I got for filling my 996.  I was very much dreading that job given the fact the car has 3 radiators that are in the front of the car and the engine/over flow bottle is in the back of the car.  The tool made it such a non event.  Hook it up, pull a vacuum, suck in all the coolant.  Run the car with the heater on until you get heat out of the vents, let it cool off, top off the over flow.

Yeah! Isn't it great? 

I have one of those too and it's amazing.  A professional mechanic passed on a word of warning to me about them.  On more than one occasion, he's had a fill using the vacuum tool result in a leaking water pump which results in general unhappiness for all involved.

I'm not sure what I'm going to do with that info.  Be cautious about how much vacuum I pull, I guess.

In reply to mfennell :

The one word of caution I got is to be careful how much vacuum you pull on an old car.  You can damage the hoses/plastics if you pull all the vacuum...

Well,  it is going to take some nerve to admit that it was me all along. There is a semi-hidden Sensor for the intake cam position on the front of the engine under and behind some brackets. The harness connector side had fallen behind another bracket that I couldn't see. I missed plugging it back in. I feel simultaneously stupid and ecstatic. So, I guess the moral of the story is, check the simple stuff first. Did the three drive cycles and the permanent code cleared itself. 
 

lesson learned number two: don't let me work on your car. 

It happens to all of us.  I left a vacuum hose disconnected from under the intake manifold of a MX-6 one time after replacing the valve cover gasket.  A mechanic found it months later when replacing the distributor.  Oddly, no check engine light, probably because it was ODB1. 

ODB1= Ole Dirty Bastard. 

Thanks for comisserating.