P0340 Camshaft Position Sensor Circuit Malfunction

[TimaruStagea]

Hi guys, having trawled the internet for the past day this forum seems to be the most helpful so i figured i would give it a go posting here.

I am having trouble with my 2002 RX250 (M35?) stagea. Twice in the 8 months i have owned it, it has felt like it was going to stall on me. Without moving my foot on the accelerator it has surged and then dropped off. Both time this happened was as i was pulling out of my driveway and up the hill i live on so the car was cold both times.

On both occasions the check engine light has come on. The first time the car would not start for about 2 hours, the second time which was only yesterday it didn't actually stall and i was able to drive home no problem however the check engine light is still on. From what i can tell (i only found out about the ECU fault codes reading the forum today) it is coming up with a 0340 code (i will upload a video of the light blinking to YouTube later if anyone doesn't think this would be correct).

As i didn't know that i could check the codes myself i had no reason not to believe the garage who serviced it (part of the second hand dealership i purchased it off) when they told me that there was nothing physically wrong with the car and that sometimes gremlins like this occur and that it would probably never happen again. It was within the warranty period last time it happened but its not this time. I am taking it to them in 2 hours to get them to look at it again, if they tell me that there is nothing wrong again is this likely? Or is there an issue here that needs to be addressed before it causes any major damage?

Any advise on what i should do from here?

[zei20l]

replace the two CAM sensors on the back of the motor. no physical damage should occur, but its a PITA to drive like that. and when it doesn't start................ well, ask craig about that one!

[TimaruStagea]

Its going to the mechanics in about an hour so I am going to ask them to replace the sensors not just reset the ECU this time. Hopefully that will fix the minor annoyance of the car surging sometimes while I am driving along the long boring road to work

[Daleo]

Mark the sensors in an unobtrusive way;(think paint pen, or a series of scriber marks) then you can verify whether or not they have done as you asked.

[TimaruStagea]

Now that I have an idea of what's wrong I will. Last time they told me that they didn't do anything as they couldn't find anything faulty. I just hope that this solves the issue as I really love this car and its a shame to have running issues with it as its my daily driver

[Jetwreck]

How unusual for a workshop to not know what they are doing with an m35.

If you have the money replace all three sensors with genuine Nissan parts.

[iamhe77]

How unusual for a workshop to not know what they are doing with an m35.

If you have the money replace all three sensors with genuine Nissan parts.

Deadpan sarcasm! Surprised, but did enjoy

Also, besides replacing the two cam sensors and the crank sensor, check that the prongs on the connectors are nice and straight. I had this error a long time ago and it turned out that the prong on the connector was bent.

[zei20l]

its entirely possible that your car didn't receive the recall to have them replaced from factory. check the engine bay plate, make sure it has two round silver dot things on it. anyway, they will still need replacing, or at the very least checked, before the car operates correctly. resetting the ECU is NOT a long term fix.

[TimaruStagea]

So after hooking it up to their computers they determined that its an issue with the variable valve timing (there was more than one error code it would appear) gotta pull the front of the engine off now I guess

[scotty nm35]

More likely to be the sensors playing up imo.

[zei20l]

More likely to be the sensors playing up imo.

quoted because he is probably right. if it cant determine the position of the cams, it cant advance them

[TimaruStagea]

If it was the VVT wouldn't it do it more regularly than twice in 8 months? What exactly would I look for and where to see if it got the factory recall to replace the cam sensors?

[Commsman]

As Iain said, find the build plate in the engine bay (drivers' side wheel arch) & there should be 2 round silver stickers nearby, each about 7mm across.

One of mine says R186 on it, the other is blank.

[scotty nm35]

If it was the VVT wouldn't it do it more regularly than twice in 8 months? What exactly would I look for and where to see if it got the factory recall to replace the cam sensors?

You could just learn to reset the ecu yourself, that way it doesn't cost you a cent.

[TimaruStagea]

There is always the possibility that the stickers came off but I don't see them, I take it there was a known fault with them

[scotty nm35]

It was a factory recall.

[TimaruStagea]

Ok so hopefully my final update. The CAM sensors were replaced today. It feels like a different car almost, no random loss of power while driving on a straight flat road. Only time will tell if its fixed the random stalling problem I guess. Just wanted to say thanks to the community for all your input. I honestly wouldnt have known where to even start if it wasnt for you guys. Cheers

[zei20l]

no worries, glad its all working!

so it was the sensors on the back of the motor yes?

[TimaruStagea]

They told me they replaced the CAM sensors. My wife took it in for me while I was at work so I didn't actually see them do it and I cant tell the difference myself but it seems to be working all good now

[zei20l]

cam sensors are the one at the back of the motor. the ones we were talking about.

the ones on the front are the solenoids that advance/retard the cam timing.