I've seen a few other threads on this, but nothing very recent that I can find. We've had this vehicle since new, and not had any major issues until recently, after we decided to buy out the lease (of course!).

Here are the symptoms:
- Occasionally notice a noisy/rattle sound when starting after engine is at rest for a few hours. Noise goes away after a few seconds.
- Check engine light (MIL?) and traction control light will intermittently come on at start (not while driving). Usually tied to the noisy start condition.
- When lights are on, driving will sometimes feel normal, but other times the engine is very sluggish or non-responsive, and then will kick in to "normal" power again after a bit.
- Lights normally turn off after two or three successive driving cycles in a day (first traction control light goes off after restart, and then check engine light goes off after another restart or two).
- The only code being thrown (per my friends at the local auto parts store) is P0340 (Camshaft position sensor circuit).
- Replaced the back (easy to access) camshaft position sensor - no change in behavior.

Reading through the forums the last day or two points me to cam phasers. Specifically, an older post from Master Tech (thank you!) in DIY gave clear steps regarding the noisy start condition with a P0340, and stated that the fix was to replace both Exhaust Camshaft Phasers.

I took a look at my Haynes manual, and though I have no problem getting my hands dirty, I can't afford to mess this up. Is cam phaser replacement even something I can do without an engine lift or a bunch of other specialty tools? If I take it to the dealer, any idea how many arms and legs it might cost to get this done?

Thanks in advance!

 

Someone have a solutions?
I have the same problem.

Thanks

 

I have exactly the same issue with a 2011 GC. Any news on a solution?

 

I'm experiencing the same issue. I changed Bank 1 cam postion sensor and did not resolve the problem. I'm going to change crank shaft sensor TMR. How did you end up fixing this issue?? Thanks

 

Any solutions? Experiencing the same problem with my 11GC

 

From my research,it's pointing to a issue with the camshaft phasers.

 

P0340 is usually a bad CMP sensor, not a CKP sensor. The rattling and lack of power is the symptom of a Variable valve timing/phaser issue. But before you start throwing parts at this, check oil level and oil condition. The VVT system advances and retards timing using pulsed oil pressure. If there's sludge in the system, you've used the wrong oil viscosity or your dangerously low on oil, you can get the noise issues. A shop would go into MODE $06 to see if there are any bad values in the VVT system that haven't quite reached the threshold of setting a phaser related code.

You can trouble shoot the CMP sensors up to a point using a digital meter. You can check for the 5 volt reference and ground and check for opens and shorts to ground. BUt you really need a scope to see actual CMP performance. The thing shops see most is intermittent CMP performance that would be impossible to catch without a scope. See wiring diagram

 

I changed the rear Cam sensor and crankshaft sensor. The van has fresh synthetic oil with the correct viscosity. The issue only arrises on start up. I'd say %95 of the time it starts fine. The other %5 it makes that " rattling" noise and sometimes triggers the check engine light P0340. I'm thinking of trying some sort of engine flush. Try to clean out the phasers.