Ok, I've read quite a few posts trying to find an answer. I purchased a 98 Ranger, 2.5L 5 speed with 114k miles about 5 weeks ago. 2 weeks later the CEL came on with either "P0340" or "P0345"... I don't remember which, both of which have to do with the Camshaft Position Sensor. I replaced the Camshaft Position Sensor (CPS), regretably with a non OEM part. CEL reset, no problems, runs fine. This past Thurs the CEL came on again with the code for "Camshaft Position Sensor- Circuit Malfunction", I believe that code is "P0345". So I took out the new sensor and put the original one, from when I bought the truck, back in. Truck ran fine, no problems, no CEL. Well, 4 days later, today, the CEL is back on and truck is not running smooth. (Obviously b/c the timing is not right b/c of the sensor) Now, I read in another post from April, Here's the link... https://www.ford-trucks.com/forums/8...dtc-p0340.html about someone else having this problem. Should I even bother spending the $80 for an OEM Motorcraft Sensor, or just tear the motor apart looking for damaged wiring. Mechanics that I have spoken to say that it is a wiring issue since the code is for a "CIRCUIT MALFUNCTION" and they tell me not to spend the money on another sensor. Any and all help is greatly appreciated!!!

 

Ok, I figured I would post an update on my situation in case there are other people with this same problem.... The "CPS" has 2 wires connecting it, a blu/or and a red/grey. The blue and orange is a direct feed to the computer to pin 85. The red/grey includes other sensors on the same circuit going to pin 91. Seeing as how there was only the one code for the CEL, I knew that the wire causing the problem was the blu/or. I cut both ends of the wire, leaving them connected at the computer and the plug for the sensor, and spliced a new wire to it running away from the block so this will not happen again. This saved me alot of money from a repair shop of having to remove the AC Compressor and the power steering pump brackets. Hopefully this will help someone else!!

 

Necessity is the mother of all inventions, or Mcgiver at work here, hey whatever works!!!! I've been known to re-engineer a few things now & then myself!!! lol

Hope this puts a lasting fix on your problem, good feedback.

BTW Welcome to FTE!!!!

 

I suggest you have wiring/connectors issues. having this kind of problem I use to check signal on sensor and on PCM with o-scope...

Well, I advice you to rewire cam.pos sensor wires only.

 

Seeing as how the problem would go away for a few days after you'd unplug the CMP & you've now rewired the CMP, If the problem returns, I like Pablo's idea about it being a connector/contact problem. So put the engine wirng harness CMP electrical connector, or it's contacts on your suspect list!!!!

 

It has now been a month since correcting the wires on my Camshaft Position Sensor and I have not had any more issues with it. So, the fix worked for me. Thanks to all who replied with help and suggestions!!