06 Rubicon - P0344

Blue XJ · 02-13-2020, 05:23 PM

My buddy has a 06 Rubicon (4.0, auto) that throws code P0344 (Camshaft Position Sensor Intermittent Interruption Bank 1 Sensor 1) that puts the into limp mode and only lets it rev to about 2500 rpm until the code is cleared. It only throws the code when the engine temp is cold, once its up to operating temp and he clears it, the code doesn't come back. But if he clears it while the motor is still cold, it comes right back.

He has replaced the cam sensor and the entire OPDA assembly and still has the issue. The Jeep dealer had it for almost a month and couldn't figure out what was wrong with it. They replaced the timing chain thinking it was worn out, but that didn't change anything.

The only thing we can come up with is a possible cam sensor crank sensor out of sync issue when it's cold. It looks like the two sensors can be ~15 degrees (crank angle) different and still work fine. Our thought is that when it is cold, the ECU is retarding the timing and it's somehow falling outside of the 15 degree window, until the temps come up and it throws the timing back at it.

I never knew a Jeep motor could go into limp mode until this issue came up, and we haven't been able to find much info online, other than the cam/crank difference and possibly a bad cam.

Anybody ever hear of a similar issue, or have any ideas where to keep
looking? He's gonna throw a crank sensor at it, since they are cheap, but the code specifically states cam sensor.

xj_man_646 · 02-13-2020, 10:10 PM

That is an interesting one for sure.

Has the dealer inspected all the wiring? Sometimes there can be weird interactions when stuff is cold vs hot. It could also be some strange interaction with the sensor and the air gap, but my experiences with crank position sensor intermittent issues generally goes back to the wiring at some level (I know this is related to cam position sensor but as far as I have always understood they operate on similar principles). Inspecting the pins in the connectors would be a good place to start with.

Blue XJ · 02-14-2020, 07:36 AM

I don't know if the dealer did, but my buddy said he cleaned all the connectors and checked the pins. I doubt he check the length of wire for a break somewhere.

I found this thread that matches his symptoms almost exactly. The end result for that one is the cam gear and dizzy gear were worn enough that there was too much slop when cold and it set the light off, once it warmed up an the metal expanded, the problem went away.

https://www.jeepforum.com/forum/f9/2...topics/3537194

nblehm · 02-14-2020, 08:17 AM

Codes are just starting points. I had a 3.6 throwing a intermittent cam sensor circuit code and it was the oil filter bypass valve in the filter housing jiffy lube broke when doing the oil change. Granted newer car with vvt but just making a point about codes.

Imo you need to find somebody or shop that are good with an oscilloscope. Dealers for the most part dont train or use them. Then you will actually know what is being put out to the pcm. Can compare to known goods and go from there.

nblehm · 02-14-2020, 10:19 AM

Lots of wobbly cam sensor synchronizer assemblies

Blue XJ · 02-14-2020, 02:55 PM

Is the synchronizer assembly part of the oil pump drive assembly?

nblehm · 02-14-2020, 03:10 PM

Quote:

Originally Posted by Blue XJ

Is the synchronizer assembly part of the oil pump drive assembly?

Yeah what replaces the distributor in the coil on plug stuff.

Blue XJ · 02-14-2020, 03:16 PM

He replaced that once, maybe he got a bad one...

Cobound · 02-14-2020, 05:44 PM

Time to scrap it and buy a 2012 +

Blue XJ · 02-14-2020, 05:56 PM

He has a few actually, he just picked up a 78 Cherokee Chief and it putting the 383 stroker motor from his blazer in it, it puts out 575 on the dyno and he just converted to fuel injection. He had the 383 in the TJ for a while, but decided to go back to the 4.slow.

02-13-2020, 05:23 PM	#1
Blue XJ Senior Member Join Date: May 2007 Posts: 3,857	06 Rubicon - P0344 My buddy has a 06 Rubicon (4.0, auto) that throws code P0344 (Camshaft Position Sensor Intermittent Interruption Bank 1 Sensor 1) that puts the into limp mode and only lets it rev to about 2500 rpm until the code is cleared. It only throws the code when the engine temp is cold, once its up to operating temp and he clears it, the code doesn't come back. But if he clears it while the motor is still cold, it comes right back. He has replaced the cam sensor and the entire OPDA assembly and still has the issue. The Jeep dealer had it for almost a month and couldn't figure out what was wrong with it. They replaced the timing chain thinking it was worn out, but that didn't change anything. The only thing we can come up with is a possible cam sensor crank sensor out of sync issue when it's cold. It looks like the two sensors can be ~15 degrees (crank angle) different and still work fine. Our thought is that when it is cold, the ECU is retarding the timing and it's somehow falling outside of the 15 degree window, until the temps come up and it throws the timing back at it. I never knew a Jeep motor could go into limp mode until this issue came up, and we haven't been able to find much info online, other than the cam/crank difference and possibly a bad cam. Anybody ever hear of a similar issue, or have any ideas where to keep looking? He's gonna throw a crank sensor at it, since they are cheap, but the code specifically states cam sensor.

02-13-2020, 10:10 PM	#2
xj_man_646 Senior Member Join Date: Oct 2004 Location: MN Posts: 27,739	That is an interesting one for sure. Has the dealer inspected all the wiring? Sometimes there can be weird interactions when stuff is cold vs hot. It could also be some strange interaction with the sensor and the air gap, but my experiences with crank position sensor intermittent issues generally goes back to the wiring at some level (I know this is related to cam position sensor but as far as I have always understood they operate on similar principles). Inspecting the pins in the connectors would be a good place to start with. __________________ - James I like diesels

02-14-2020, 08:17 AM	#4
nblehm Needs moar dagger Join Date: Feb 2004 Posts: 26,781	Codes are just starting points. I had a 3.6 throwing a intermittent cam sensor circuit code and it was the oil filter bypass valve in the filter housing jiffy lube broke when doing the oil change. Granted newer car with vvt but just making a point about codes. Imo you need to find somebody or shop that are good with an oscilloscope. Dealers for the most part dont train or use them. Then you will actually know what is being put out to the pcm. Can compare to known goods and go from there. Last edited by nblehm; 02-14-2020 at 08:21 AM.

02-14-2020, 05:44 PM	#9
Cobound - The Don - Join Date: Sep 2002 Location: MN Posts: 49,170	Time to scrap it and buy a 2012 + __________________ To each his own. Not all those who wander are lost. The great irony - triggered snowflakes accusing triggered snowflakes of being triggered snowflakes

02-14-2020, 07:36 AM	#3
Blue XJ Senior Member Join Date: May 2007 Posts: 3,857	I don't know if the dealer did, but my buddy said he cleaned all the connectors and checked the pins. I doubt he check the length of wire for a break somewhere. I found this thread that matches his symptoms almost exactly. The end result for that one is the cam gear and dizzy gear were worn enough that there was too much slop when cold and it set the light off, once it warmed up an the metal expanded, the problem went away. https://www.jeepforum.com/forum/f9/2...topics/3537194

02-14-2020, 10:19 AM	#5
nblehm Needs moar dagger Join Date: Feb 2004 Posts: 26,781	Lots of wobbly cam sensor synchronizer assemblies

02-14-2020, 02:55 PM	#6
Blue XJ Senior Member Join Date: May 2007 Posts: 3,857	Is the synchronizer assembly part of the oil pump drive assembly?

02-14-2020, 03:16 PM	#8
Blue XJ Senior Member Join Date: May 2007 Posts: 3,857	He replaced that once, maybe he got a bad one...

02-14-2020, 05:56 PM	#10
Blue XJ Senior Member Join Date: May 2007 Posts: 3,857	He has a few actually, he just picked up a 78 Cherokee Chief and it putting the 383 stroker motor from his blazer in it, it puts out 575 on the dyno and he just converted to fuel injection. He had the 383 in the TJ for a while, but decided to go back to the 4.slow.