P340 Code

Hello everyone, I am new member here. I am a long time mustang owner, I think I am somewhere around 10, which makes this more frustrating for me.

I recently picked up an 02 Roush. Car ran like crap, did a full tune-up like to any new-to-me vehicle. Ran the codes and found P0340 Cam Position Sensor Circuit Fault. I have a running parts car, so I swapped alternators and cam sensors with no change. Went and had the alternators tested and they came back good. I started to get into the harness to check the pigtails and see no issues there. I even ordered a new cam sensor just incase. Any pointers? I checked cylinder 5 COP connector and I and seen 5 volts, so I assumed there wasn't a break in the harness. Any help would be appreciated.
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Active Member
Jul 2, 2019
A circuit fault would suggest there's a problem with one of the two wires to the cam sensor. I know on my 98 the cam sensor - runs through a shared signal ground wire, so I would assume the PCM is complaining about the + side. Either way, they both run to the large square connector on the passenger firewall and then to the PCM; grab a wiring diagram and a multimeter and test for continuity in each location. I suspect you'll find a short.
Hey, thank you for the reply. I've been waiting for some help. I've checked for voltage coming out of the cam sensor and it moves between 3-4.7 volts. So, there is signal coming out. I've started to trace my way up the harness with no damage to be seen yet. I will take you advice and look there.