Just thought I would share what took me 16 hours to find in case someone has the issue in the future.

 

A customer traveling through on I-40 with a fifth wheel rv in tow got a check engine light and stopped by the shop for us to have a look. Truck has 212,000 miles. Hooked up Snap-on diagnostic. Found a stored P0341 fault. Cleared fault and started engine and watched live data on the Snap-on. Cam speed readings were all over the place. Swapped places with CKP and CMP sensors and still had erratic cam speed readings. Pulled entire engine sensor harness off of engine to give a thorough inspection. Found 2 wires on CMP sensor plug in bad shape so I replaced all 3 wires on the CMP sensor plug. I also found a broken wire on the wastegate solenoid so I replaced both wires on the wastegate solenoid even though ECM didn't have a fault to indicate an issue. I reinstalled the sensor harness and fired the engine up. Still had erratic cam speed readings. Replaced CMP and CKP sensors with new genuine Cummins. Still getting erratic cam speed readings. Replaced MAP and rail pressure sensors with new genuine Cummins since they share the same 5 volt and ground with the CMP sensor. Still erratic readings on cam speed. Finally decided to pull the front cover on the engine. I found 1 complete bolt and 1 head of a bolt laying down in the bottom gear housing. The bolts belong to the cam thrust plate and being they not in place allowed the cam to walk. Luckily they some how didn't get caught up in the gear train on their way down. I managed to get the broken bolt out of the block with a pick then installed and torqued new bolts to 212 inch pounds. Reassembled front of engine and everything taken off to access front of engine. Fired engine up and now have steady cam speed readings that match crank speed. No more P0341 fault.

 

Owner was not sure if there was ever any major engine work done in the past since they have only owned it for about 6 months.

Ive heard of this occurring on 24V 2nd Gen trucks as well. Rare but does happen. I would have to ask the owner if he changed cams? Its strange to see specs on the end of the shaft.

Fighting same issue on my 07 5.9.  i have swapped sensors, next step will be the wiring.  I have seen one other post about the bolts, now i'm thinking it may be more common than i wanted to believe.  if i can't fix it with wiring, next stop will be pulling the cover....

 

While it's not a common issue, it does happen and the cam sensor goes erratic. It's certainly worth pulling the timing cover and inspecting. 

5 hours ago, dmckeehan said:

Fighting same issue on my 07 5.9.  i have swapped sensors, next step will be the wiring.  I have seen one other post about the bolts, now i'm thinking it may be more common than i wanted to believe.  if i can't fix it with wiring, next stop will be pulling the cover....

 

 

If you have a way to monitor live data from the ECM it will help diagnose too. I was seeing CMP readings jumping all over the place when the engine was idling at 850 rpm. CMP readings were only erratic at idle.

 

Best advice I can give you is to remove the entire sensor harness and look for damage while checking resistance on wiring. Also look for corroded and spread pins. Pulling the left front tire and plastic inner fender allows easy access to ECM.

 

Once you are satisfied that the harness is in good shape I would then pull the front cover. Front cover is easy to pull once the condenser, CAC, and radiator are out of the truck. DO NOT REUSE THE FRONT CRANK SEAL, you need an install sleeve. A new front crank seal will come with the install sleeve even with Fel-pro. There is no gasket made for the front cover so plan on a couple of tubes of Ultra Grey RTV to seal up the front cover. That's exactly what Cummins did to seal it.

Edited July 7, 20186 yr by 04Mach1

Thanks guys.  definitely will check the wiring.  I'm having intermittent long cranks on start.  sometimes it starts perfect, sometimes it cranks for 3-5 seconds before cranking.  New injectors, new tubes, 6-7k rail pressure on start.  no fuel in my oil.  just a pesky code for the cam sensor. 

On 7/6/2018 at 5:36 PM, AH64ID said:

While it's not a common issue, it does happen and the cam sensor goes erratic. It's certainly worth pulling the timing cover and inspecting. 

 

Curious... Your thinking a possible thrust plate issue where the bolts have walked loose? 

Edited July 9, 20186 yr by Mopar1973Man