Problem with DTC PO342 Camshaft Position sensor circuit low

[LSXstart]

Just new to this game......running a 24X LS7 on a LS1 pcm. Generally engine starts & idles well. However occasionally engine refuses to start - backfiring or not firing at all. Sometimes it will take 10 or a dozen goes at turning the key on and off before it goes. Other times just once or twice. Pcm comes up with "camshaft position sensor circuit low", which I am told is a problem with the ground signal wire. I have checked the cam sensor wiring harness and it appears ok. Not sure what do do next???

Being a 24x engine we are running a 2x camshaft timing wheel.

[exploder]

I don't know if it will help you much, but the 3 bolts that hold the cam to the timing gear sometimes come loose and cause the code....ask me how I know. There have been several others that it has happend to. I red locktited my bolts and have been trouble-free since.

[LSXstart]

Thanks exploder. Will check this......

[3fingas]

What year harness? Some have a cms loop with male and female connector by top tensioner. Purple weatherpak. If unplugged or eliminated car will start intermittently.

[LSXstart]

Its a new custom harness so don't think this could be the issue. But will check.....thanks

[joecar]

Just new to this game......running a 24X LS7 on a LS1 pcm. Generally engine starts & idles well. However occasionally engine refuses to start - backfiring or not firing at all. Sometimes it will take 10 or a dozen goes at turning the key on and off before it goes. Other times just once or twice. Pcm comes up with "camshaft position sensor circuit low", which I am told is a problem with the ground signal wire. I have checked the cam sensor wiring harness and it appears ok. Not sure what do do next???

Being a 24x engine we are running a 2x camshaft timing wheel.You mean a x1 cam wheel, right...? Do you have any pictures...? Just a thought.


Camshaft Position Sensor (http://127.0.0.1:9001/servlets/BlobShtml?ShtmlFile=684352&evc=sm&pubid=238&cellId=32590&mspsdsubkey=1724#ss3-684352)

The camshaft position (CKP) sensor works in conjunction with 1x reluctor wheel mounted at the rear of the camshaft. The CMP is used to determine the top dead center position of cylinder #1, and will synchronize with the 24x CKP sensor signal for quicker starting. The PCM will detect an increase in the mass airflow (MAF) sensor signal when the engine starts. The CMP signals are output as a digital waveform.

[jfpilla]

I remember that there was an issue, at least a year ago, that the sensor wires needed to be reversed. I don't remember more than that. Maybe someone knows more?

[LSXstart]

You mean a x1 cam wheel, right...? Do you have any pictures...? Just a thought.

Thanks for the advice guys. Fingers crossed but looks like the problem was a faulty cam sensor.

[joecar]

hi mates. definitely have the same problem the Pcm comes up with camshaft position sensor circuit low. Now I need to replace the camshaft position sensor, i removed the wiring harness, then the 8mm bolt, i removed it slowly and the sensor split in 2 pieces? but i don't know what will be the next step. I appreciate any help. thanks :cheers:Where did it break off...? Does the piece in the block move at all when you wiggle it...?

Which year/model/vehicle and which eng/trans RPO's...?

[DrkPhx]

The Gen IV engine have the camshaft position sensor in the front timing cover. It can be used with a LS1 PCM however the two outside wires must be crossed to make it work correctly or you can buy an aftermarket adaptor that plugs in between the harness and sensors.

[joecar]

Has this ever happened to anyone else (cam sensor breaking off)...?

[ I had a crank sensor break off inside its bore in a 2.8L some years ago ]