03' Explorer E.B, 4.6L V8 Timing Chain / P0340

[jdishong]

Thanks to this forum I was able to replace my timing chain guides and chain tensioners but now here is my problem:

P0340 code (Camshaft Positioning Sensor Failure). Codes have been cleared mutiple times and they re-appear.

Engine runs great but cannot get rid of the codes.

I have verified sensor signals are getting to PCM (0.35 V AC-RMS and I was able to hook up an oscilloscope and did see the pulses.). I was also able to verify no wiring problem as well. This problem did NOT exist prior to my repair work ...SO..

with the engine running great, is it possible that my chain may have slipped one-tooth off of the crankshaft sprocket. I say crankshaft because I know I did not slip tooth on the camshaft sprockets as I used twist-ties and had them anchored down. Unfortunately when I removed the chain tensioner, there was enough slack to where it is possible the chain may have slipped on the smaller crankshaft sprocket.

I talked with a dealer shop foreman today and he tells me that the engine can run just fine and the chain off by one tooth. I wouldn't have thought this to be true; if so, I need to go back and tear-down and align.

Chains were NOT taken off during the repair.

Thoughts or suggestions appreciated!

 

[Birdy]

My guess is that you're right. I think I'd check that chain timing. 9 times out of 10 a new problem is caused by something that was done, in my experience.

 

[RRousta]

did you ever solve this problem?

I am going through a similar problem, although I believe its the PCM and not the timing chain (I have had the chains, guides, tensioners all replaced).