# P0340 - Camshaft Position Sensor A Circuit (Bank 1 or Single Sensor)



## cmdshft (Oct 17, 2011)

Hello again.

As some may know, I got my boost issue fixed with a simple hose clamp and since then, I've gone into limp mode a few times. Went from pulling 11psi to 5psi while driving. Decided that once I got to work the other morning I would hook my pocket scanner up and check for new codes because I've also had some difficulty starting the car from cold a few times.

P0340 - Camshaft Position Sensor A Circuit (Bank 1 or Single Sensor)

P0300 - Random - Multiple Misfire Detected

Both codes came up and I checked a few google links as well as Ross Tech's site and came to the conclusion that I may just need to change the CamPS, so I picked up a replacement sensor and changed it once I got home. 10 minutes after I changed it, I cleared codes, started the car and let it idle for a bit, went for a short drive and then re-scanned for codes. P0340 came back again as a confirmed code, but no longer having misfiring codes. I do not have any other codes for timing such as advance or retard, nor an implausible signal code.

I let the car cool off to cold and unplugged the sensor to start it again, and the car easily started up. I immediately shut it off, connected the sensor and the car took a few extra seconds of crank to start.

I again google'd for a bit and often I see that the fix is a timing re-adjustment. *The car idles and drives fine through the RPM range.* I see many posts that say that the exhaust cam may be off time by half or whole tooth and the code would not go away until the timing was aligned properly. I contacted the seller of the car who said that the person they bought it from did a timing belt change but was unable to specifiy much about what was done. I do not know if the tensioner was replaced or the water pump.

Is it entirely possible that the timing belt job was not done properly despite my not having issues with idle or driving, or that I jumped timing after getting boost back? This code never came up before the boost was fixed so I am really thinking I jumped timing slightly.

I am taking the car to my mechanic tomorrow to have the timing inspected and corrected if need be. Should I also just replace the tensioner at least for ****s and giggles and peace of mind? I am strongly leaning towards doing so due to the fact that I suspect I have a faulty tensioner and jumped timing AFTER fixing my boost. If the timing job was bad from the get go, this problem should have surfaced as soon as I picked the car up I think.

I will also have my mechanic inspect the cam chains. I have a suspicion there may be an issue with the chains because I do hear a bit of a rattle on the driver side of the motor but can't really pinpoint where it's coming from.

I will report back if my issue goes away.

EDIT: I actually think the noise may be the belt tensioner. It sounds like a rattle, not a tap or "chinging" sound that chains might make. Which means if it's failing, I probably jumped timing. Which means on the way to the shop tomorrow I am picking up a new tensioner... Joy.


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## cmdshft (Oct 17, 2011)

Timing was off by just over a tooth at TDC. Had the timing redone and the P0340 code went away.

So if you get this code, make sure your timing is ok. Misaligned timing will absolutely throw this code and in my case wont throw and advance/retard code.


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## Human Garbage (Jan 3, 2014)

If your rattle sounds metal on metal (think shaking a spray can) and happens largely at idle or sub 1500 RPM, it is likely a tensioner. From the time I heard mine in the morning at work until the time I got home mine jumped a couple of teeth. Anymore and I would have been rebuilding the engine. Literally 30 miles from the first warning too, so acting quickly is the key.

The tensioner that went on me was Uro brand. It was absolutely shot and leaking everywhere in less than 30K. If you have to replace yours, buy NTN (the OEM part) it costs double and then some but worth every penny for peace of mind. Given how important the tensioner is, its not worth saving a few bucks to potentially spend thousands when it fails IMHO.

Thanks for posting up the fix to your code issue. So many members start threads and don't update with what cures it. You have helped many in the future by doing so... Cheers.


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## cmdshft (Oct 17, 2011)

Human Garbage said:


> If your rattle sounds metal on metal (think shaking a spray can) and happens largely at idle or sub 1500 RPM, it is likely a tensioner. From the time I heard mine in the morning at work until the time I got home mine jumped a couple of teeth. Anymore and I would have been rebuilding the engine. Literally 30 miles from the first warning too, so acting quickly is the key.


After doing the timing the right way, the noise has mysteriously gone away. I'm not sure what it was, but it's gone. I'm still planning on doing the chain tensioner at some point but for now, I'm good. I'm doing the valve cover gasket along with the tensioner gasket this weekend as there is a spot of oil/grease around that area and the tensioner gasket it notorious for leaking apparently.



Human Garbage said:


> The tensioner that went on me was Uro brand. It was absolutely shot and leaking everywhere in less than 30K. If you have to replace yours, buy NTN (the OEM part) it costs double and then some but worth every penny for peace of mind. Given how important the tensioner is, its not worth saving a few bucks to potentially spend thousands when it fails IMHO.


My mechanic and I inspected the tensioner and other parts to make sure they were good, whoever owned the car before the person I bought it from did a complete timing job (pump, belt, tensioner, etc). No leaks from the tensioner, it looks new as does the water pump, belt pulleys are clean and make no noise at all. So I have some peace of mind for the next 70K miles hopefully.



Human Garbage said:


> Thanks for posting up the fix to your code issue. So many members start threads and don't update with what cures it. You have helped many in the future by doing so... Cheers.


Absolutely! I noticed that as well, many threads just die with no updates.


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## Human Garbage (Jan 3, 2014)

Good to hear man! Just for peace of mind I check the tension on the timing belt whenever I'm in there or each oil change at the very least. If you can twist it more than 90* then there is not enough tension and you have to look further. Considering how high the stakes are when it slips or breaks I figure its good to do once in a while... Sounds like you think the same way.


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## Brake Weight (Jul 27, 2006)

cmdshft said:


> Hello again.
> 
> As some may know, I got my boost issue fixed with a simple hose clamp and since then, I've gone into limp mode a few times. Went from pulling 11psi to 5psi while driving. Decided that once I got to work the other morning I would hook my pocket scanner up and check for new codes because I've also had some difficulty starting the car from cold a few times.
> 
> ...





cmdshft said:


> Timing was off by just over a tooth at TDC. Had the timing redone and the P0340 code went away.
> 
> So if you get this code, make sure your timing is ok. Misaligned timing will absolutely throw this code and in my case wont throw and advance/retard code.



Bumping this one. This describes mine nearly identical. I got some more codes but I was doing some spirited driving at the time. p0351, p0353, p0354, p0322, and p0321. Those all cleared but the above descriptions and picture are identical to the recurring code, p0340, and related issues.

I’ll move the timing forward a tooth and see if this doesn’t clear things up. Maybe tomorrow.


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## Brake Weight (Jul 27, 2006)

One tooth retarded.


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## Brake Weight (Jul 27, 2006)

I went ahead and made time to move one tooth over. Problems solved and no codes at all. I was looking at changing the Cam and Crank Position Sensors. I checked the ohm them both for future reference should anyone need to know. Taking a pic and holding the multimeter leads isn’t easy after wrenching for 1.5 hours. 

One tooth is all it needed. Even though the Bentley says one is within spec. Unless I misinterpreted this. 






















Cam Position Sensor. Note the OHM setting at 2000K. 










Crank Position Sensor. Note the Ohm setting at 2000.


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## Brake Weight (Jul 27, 2006)

I got a couple of codes back today. I was rev matching as I downshifted and the RPMs went to 0 and then when they came back the car backfired. 

P0321 and P0322. Codes cleared and the car cranks, idles, and runs just fine. 

Any ideas? Seems oddly intermittent to me.


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