Code P0340 driving me NUTS

[TheSushiGod]

Greetings,

My 2002 3.7L Liberty is suffering from intermittent crank but no starts. When it cranks and doesnt start it throws a P0340 code. Eventually it will start if I keep trying or let it sit a bit. Doesn't matter if the motor is warm or cold it's quite random when it happens.

While running the vehicle runs great. Great acceleration no stumbles etc. Zero issues.

I've replaced the camshaft sensor and the crank sensor 2 times now and the 2nd time I've used NTK parts since mopar doesn't make them anymore. The problem persists. I've also disconnected the battery while touching the positive cable to the negative to attempt to force a "relearn." I've also replaced the ASD relay on the chance that was not triggering. No change. I've inspected the pig tails and wires and they look fine.

I've read that some people have had issues with timing chain slack and tone rings as well. The jeep has 123k miles on it and it's all original. Wouldn't a tone ring or slack in the timing chain cause rough running conditions, limp mode, etc? Does anyone have any ideas or experienced this?

 

[Rokk]

I pulled this code on my 2012 once so I’m not sure if it will apply to a 2002 but it might help. My problem turned out to be a compromised connection at the temp sensor. Apparently these sensors are connected to the same circuit and can affect each other. My symptoms were different but it couldn’t hurt to have a look at the other sensors. There aren’t that many on the 3.7

 

[blackhawk]

Take a pic a what I found in all data related to p0340 in ikj 2002

 

[TheSushiGod]

I have an update: I bought a legit Mopar cam sensor. After installing I got a no start. Zero starts and many tries. I put the Chinese one back in and boom it fired up. I confirmed it was the correct Mopar sensor. I'm starting to think maybe the Chinese sensor stretched out the pigtail so the computer cant see the Mopar one?

 

[blackhawk]

It could be, you need to scan and see if you get the open circuit code. Btw, is strongly recommend to replace both sensors at once , Crankshaft and camshaft regardless of one of them is in good condition

 

[TheSushiGod]

It could be, you need to scan and see if you get the open circuit code. Btw, is strongly recommend to replace both sensors at once , Crankshaft and camshaft regardless of one of them is in good condition

I did actually. Couldn't find a mopar crank sensor they don't make them anymore so I went with an NTK.