Strange P0340 camshaft position sensor code (1 Viewer)

[Dominic Nicandri]

The truck recently developed a check engine light. It's a P0340 camshaft position sensor. The code will appear and then after a few drives it will disappear. I logged about 1000 miles of driving after I put the replacement engine in with no codes. Now any time I rev it over 3000 RPM the code will appear. I replaced the sensor. I inspected the harness. The RPM thing worries me that it's out of time but it runs fine and I verified the timing marks. I'm going to tear it apart again tonight to verify the marks a 3rd time but right now it's not making any sense. I would think if it has skipped a tooth the computer is going to see the timing discrepancy and throw the code at any RPM not just over 3000?

 

[Dominic Nicandri]

So I pulled them covers again. If the timing is off, it sure isn't visible to the naked eye. The crank mark is hard to see with the fan pulley in the way but I got the phone pretty much over the top of it. Right cam might be a hair past the T but it's not a full tooth off.

 

[Rya]

I have the exact same issue when it revs over 3000 rpm the cam sensor lights come on.

Did you get to the bottom of it?

 

[AARONTLC]

Your timing looks good. In this picture, your crank timing mark should be lined up with a raised dot which in turn lines your cam marks up with the T’s. If you set your crank at 0 then your cam mark should be lined up with the raised straight lines just to the left of the T’s.

The T location is a secondary location where you can line up the crank with the raised dot and you can remove the timing belt without it jumping.

I would say the most common failure for a Cam Position sensor is misrouted wiring harness during timing belt replacement. I would look very close at the wiring harness that goes down from the cam position sensor down to the crank position and oil pressure sensor. Car Care Nut on YouTube did a video on this very thing about 2 months ago. The vehicle he was looking at was a 1st gen Sequoia. Good luck!

 

[Import Driver]

Your timing looks good. In this picture, your crank timing mark should be lined up with a raised dot which in turn lines your cam marks up with the T’s. If you set your crank at 0 then your cam mark should be lined up with the raised straight lines just to the left of the T’s.

The T location is a secondary location where you can line up the crank with the raised dot and you can remove the timing belt without it jumping.

I would say the most common failure for a Cam Position sensor is misrouted wiring harness during timing belt replacement. I would look very close at the wiring harness that goes down from the cam position sensor down to the crank position and oil pressure sensor. Car Care Nut on YouTube did a video on this very thing about 2 months ago. The vehicle he was looking at was a 1st gen Sequoia. Good luck!

A few months ago, before that video, I broke down 3 hours from home because a mechanic routed the wires indirectly. Delinquent mechanics are too common unfortunately. Code P0340 camshaft position sensor but it was the wire going to the crank position sensor.

But getting the code only when reving over 3k rpm seems like it would be something else.

 

[Dominic Nicandri]

No i have not gotten an answer to it. 5000 more miles this year and no change in anything, still runs fine just throws the code if consistently over 3000 rpm. I was trying to find someone with a scanner that can look at live sensor data earlier this year but got busy with other stuff.

 

[Rya]

Thanks, I'm going to see what the mechanic can find this week. I was worried I'd get into the rough idle or not starting that some people have, but so far mine runs fine, just throws the light at higher rpm.

I've looked up as much as I can and I guess I'll get them to check timing, distributer, and all the wiring around it. Those seem to be the main culprits.

 

[Rya]

So, they checked timing, changed cam shaft sensor and also the crank shaft sensor, and checked electrical and can't figure out why it throws the cam shelf sensor error only when over 3000RPM. Revving in neutral won't do it, has to be under load.

It drives fine and drives fine when over 3000 rpm and still drives fine with code light on. Light resets itself shortly after.

Maybe someday, someone will figure this one out on their vehicle. Let me know if you do! Thanks.

 

[gnob]

make sure you don't have spread terminals in the connector and also double check your alternator isn't putting off any ac voltage. or anything else underhood putting off random emf.

might be worth pulling the sensor and inspecting the cam gear.