ChiTownPack

I've searched this (and other) Jeep forums, as well as the internet and I am not finding any topics related to my specific problem. Over the last month or so I have been getting intermittent DTCs P0344 & C121C, as well as my ESP light coming on (all three always happen together). I did see a post on this forum (from 2009) where a similar thing was happening, but without the ESP light (the cause was spark plug wires arcing). I did check my spark plug wires and did not find any worn spots or arcing. I pulled out my CAM position sensor, checked for dirty connector contacts and reseated it.

I did see a TSB for the CAM position sensor and these DTCs, but one of the symptoms is hard starting and the vehicle dying, but I don't have either of those problems. When I get the DTCs, it doesn't die, doesn't start hard, not in limp in mode (I have full power).

One other thing, just before I first got the P0344 and C121C DTCs, I noticed my vehicle starting hard in the AM. I suspected that was because it was starting to get much colder and my battery is the original battery (2008). When I did get the two DTCs, I also got a low voltage DTC. I tested the battery and it was bad so I replaced it with a Diehard Platinum and have not had voltage problems since.

I wanted to see if anyone else has experienced this before I start shotgunning parts (CAM sensor, plug wires, etc).
Any suggestions would be greatly appreciated.

ronjenx

P0344-CAMSHAFT POSITION SENSOR INTERMITTENT

[TABLE]
[TR]
[TD="bgcolor: white"]Possible Causes
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]5-VOLT SUPPLY CIRCUIT OPEN
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]CMP SIGNAL CIRCUIT SHORTED TO VOLTAGE
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]CMP SIGNAL CIRCUIT OPEN
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]CMP SIGNAL CIRCUIT SHORTED TO GROUND
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]CMP SIGNAL CIRCUIT SHORTED TO THE (F856) 5-VOLT SUPPLY CIRCUIT
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]TONE WHEEL/PULSE RING
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]CAMSHAFT POSITION SENSOR
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]POWERTRAIN CONTROL MODULE (PCM)
[/TD]
[/TR]
[/TABLE]



C121C–TORQUE REQUEST SIGNAL DENIED

[TABLE]
[TR]
[TD="bgcolor: white"]Possible Causes
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]ANTI-LOCK BRAKE MODULE
[/TD]
[/TR]
[TR]
[TD="bgcolor: white"]POWERTRAIN CONTROL MODULE[/TD]
[/TR]
[/TABLE]

ChiTownPack

Thanks for the reply, ronjenx. I'll do more testing when it warms up and post the resolution when I find it.

kenmcJK

I'm getting the same DTC's on my rig not sure what to do either . Never had a problem until I had a new clutch put in?

ChiTownPack

To follow up, I ended up replacing the plug wires with a new set of Borg Warner plug wires and a fresh set of Champion spark plugs from the local auto parts store. I didn't notice any arcing or sparking with the old set, but while replacing the wires, one of the end connectors tore loose from the plug wire. It was one of the front wires so it's not like it was tough to get to or I was pulling at a bad angle. Since replacing both, I have not had any problems.