wayne613

While I and I'm sure most others would appreciate an update good or bad, if the same cam position sensor fault code re-appears, then there really only are a few reasons for it I can think of, (anyone's welcome to correct me if they can think of anything else), but this is about it IMO:

Bad alternator.
Bad sensor.
Faulty wiring.
Issue with PCM (where it this you'd more than likely have more than just that one code showing)

All of those above just mean it's either getting interference to reading a signal, or not getting one at all.

I'm betting it either won't come back, or if it does it's due to the replacement ( > .5v AC shown for test). In which case you need to contact who you purchased from and let them know, and have it exchanged post haste. If it passes and the code is still there, same deal, different part; exchange the sensor.

In any case, write down the exact code(s) this time to make sure it is actually one of the above. There are other codes indicating "camshaft position" that are not related to this, which is why I provided the TSB link for you to verify at the start. It should be 1 (or more) of those 4 codes.

got2begucci

ill be in touch.

got2begucci

so i went to JBA and had them run the code. Same code came up the PO340. He asked me if i had unplugged battery before changing out sensor and i said know. maybe i should have. he asked me if the code cleared when i put the new one in and i said yes but it came back. he also said well the code might still be going off due to memory issue. so he reset the code and since then it hasn't come on or been an issue yet. This is all after installing a new sensor and alternator. the code may have been needed to be cleared. so hopefully it doesnt come back. i am still going to do a ripple check. i got a buddy who has a multimeter and a few other things to check the car inside and out.

moosestang

I tried a ripple test with my multimeter. It only has two settings for AC, 200 and 2000, i think. Anyway it shows 30 coming from the alternator and 27 when the motor isn't even running. I'm not sure if it switches to millivolts or something, but keep this in mind when trying to do a ripple test with a volt meter.

As far as I know my alternator is functioning properly. I've never had a p0340 code.

wayne613

Afraid that's the overall quality of meter.and/or the filtering on the meter..

The +3v AC could be accurate however. The code isn't really thrown due to the AC bleed (ripple), but the RFI it causes. The AC bleed it's reading isn't really a true AC waveform. I had all but 1 diode functioning on my stock one when it was leaving me stranded. Never a single code. I never bothered to do this test, as I knew it was going loooong before it became useless. Never worried about it reeking any true havoc other than killing my battery, would have to be some seriously ****-taskic diodes for that scenario.

Definitely want to use a decent meter for this, fluke's are of course nice, but expensive as all hell. The test is really just meant as a quick and dirty one to make sure the alternator is properly rectifying what it is actually outputting, as much or as little as that might be from the AC it creates. If the meter is that far off to start, it's not a stretch to think that it's getting a false reading due to the proximity of the AC close-by when testing while it's on as well.

I've seen good results from the higher end generic ones at Lowes, still Chinese made of course, but better filtering and quality control than the ones you'd get from harbor freight or the other super-cheap stores for them.

I still use my old extech mid-grade true RMS meter (yes, Chinese) for just about anything I need a truly accurate reading from. Thankfully not stuck with auto-ranging either, don't much trust those. The crappy $20 (coupon for it at the time) from harbor freight (centech is the name I think?) I just carry with me for friend's issues and such, if it gets stolen, they'd more than likely be doing me a favor.

mustang racer06

So did the new alternator fix the issue in the end? By any chance are u running steda underdrive pulleys? Maybe that could have been the cause of the drop in your alternators output? I have them on my 06gt and the same code popped up altho the car runs fine. Not sure if the alternator is putting out less juice due to the pullys causing the problem, or if its simply time to get a replacement since i do have 84k.