I have a 2004 g35 coupe 6 speed manual with basic bolt ons and oil catch can. I bought the car a few months ago and it has given me nothing but headaches. I have codes P0340 and P0011 pop up and I have replaced both cam sensors with OEM as well as the crank sensor with OEM as well. when I get in the car and start it up I can start driving normal and once I get above 2k RPM the car goes into limp mode (VDC OFF, SLIP lights come on) the car does not let me go past 2K RPM once the lights come on. Once I turn the car off and turn it back on it will do the same thing and I haven't been able to find a shop that can diagnose this car properly. I originally took the car to Z1 and they told me that the issue was the ECM so I bought a new ECM and that did nothing. Next the car went into limp mode and I had a crank, no start situation so I replaced the cam and crank sensors with OEM parts that I purchased from Z1. Next I took out the VVT solenoid that the P0011 code called for and tested it and the solenoid moves back and forth properly and there was no oil contamination in the sensor screens so I put the sensor back in with a new OEM gasket and it is still throwing these 2 codes and going into limp mode. Also my idle is around 950-1050 RPM which is high but it also sounds like it is missing when it is at idle but I have done the Idle re-learn process and I have had no luck with it. any suggestions would be great i'm just trying to enjoy the car and would really like to keep it instead of sell it to get rid of this headache.

 

This is only my opinion, but it seems like that 2000rpm limit means the VVT is the culprit in some manner.
So, I would pull it back off, test the voltage to the wiring by setting up your multimeter, then turn the car to the on position, but do not try to start it. I'm hoping you see at least 5volts, and probably not more than 8 volts. If not, then you know it's the wiring.
Then you want to take the cover off the VVT, and run voltage to it from the battery to see if it clicks and moves. Since it's getting 12 volts from the battery, it should be an audible click as the solenoid engages. You should be able to see inside a bit and see the action happen.
Finally, check the Ohms on the VVT, I think it is supposed to be around 8ohms to 12 ohms, otherwise I would tell you it's bad.
This will let you test it without having to buy another one.

Once you do all that , if you do have to replace, you will probably need to do a reset of the ECU.

 

I pulled it off again yesterday and I stuck 12v to it and it clicked. Put the multi meter on it and it said 8.2 if I remember correctly and stuck it back in. I will try and turn the car on and see what I’m getting out of the plug next but thanks for the info. I’ll post an update when I check the voltage.

 

I hooked the car up to a buddies scanner and got some info. In the picture the freeze frame detected p0340 as the source of why the car is going into limp mode and it kicked in at 2,200 RPM. Could I have gotten a bad ‘new’ oem sensor? Or do you think that it is still related to the p0011 code with the solenoid?

 

Hmmm....so if the error points to the cam or crank sensor, can you get in there and make sure you are getting voltage to those sensors by checking the wiring? I say this since you said you replaced them and with OEM so that shouldn't be the issue.

 

I checked the voltage on them before I put the OEM sensors in because the sensors that were in the car were not oem from the previous owner and I tried to put some more in from oreillys and that is what caused the crank, no start issue but before trying to change the sensors the car would go into limp mode at 2,000 RPM as well and was not pulling the P0011 code like it is now but all of the sensors wires and plugs have been checked and referenced to the service manual for the car. I also called Z1 motorsports and they said that they do not offer any type of warranty for the sensors.

 

I would say it's time to check continuity between the ECM and the cam sensor harness.

Just focus on bank1 since that's the P0340 side.

P0011 was probably being CAUSED by the actual culprit from the cam sensor. Codes tend to cascade like that, problems with one system also cause codes to pop up for other systems downstream.

Check all the wiring around that cam sensor harness, see if there's nicks in the wire, is a pin loose in the harness, is there corrosion, OIL, or anything else that can screw up the oscillating signal from the sensor back to the ECM.

If the harness is all crapped out with oil contamination you can clean it with electrical contact cleaner just make sure you read the can to make sure it is PLASTIC SAFE! Otherwise it will literally melt the harness...

Just spray it in the harness, all over it, then let it dry, that's how you clean electrical components.

Do all this with the battery disconnected... never unplug stuff from your computer while it's powered up.

 

I’m going to pick up another OEM sensor just to rule out the suspicion but I’m going to try within the next few days to play around with the wires and trace them from the sensor and try and make it through the firewall. I’ve also got my old ecu that I want to see if that code is burned into this ecu or if It is a wiring issue but I’ll keep updating when I can. Thanks for all of the help so far.

 

Its been a few months and i've had the same issues and haven't really driven the car or looked at it until I could get it into the shop for them to look at it and they came back and said that the gallery gaskets were bad and quoted me 3,500$ to take the car apart and change the gallery gaskets plus whatever else was needed while they were in there so I got the car back a few days ago and started tearing the motor apart at home to save some money and so far we have found that the gallery gaskets on the car are fine and the motor that is in the car has had a timing job done on it recently but nothing out of the ordinary from that inspection. We pulled the timing chain off, got the water pump, thermostat ect pulled and noticed that the bank 1 passenger side cam shaft chain tensioner did not have much tension on it at all compared to the drivers side on bank 2 and that tensioner is also connected to and sits right under the vtc solenoid on the side that I was throwing the code for, also I noticed once we removed the tenisioner that there looks to be an O ring missing from the tensioner as well as a screen that is built into the tensioner has basically rotted away so that is what im left to believe is the culprit. so Im going to z1 tomorrow to pick up parts to start throwing the car back together so far weve got about 12 hours into tearing down and cleaning all of the RTV out of all of the crevices and we have are fingers crossed that there are no other problems while we try and put it back together. next is: water pump, thermostat, updated gallery gaskets, timing cover seal kit with O rings, new cam chain tensioner, valve cover and gasket for the passenger side. I will update with hopes that this nightmare is fixed.