2007 Dodge 2500 RAM 5.9L  4x4 Mega Cab (82,000 miles well taken care of vehicle): Engine died at highway speed, and will not start with no immediate electrical problems.  I was traveling on a 700 mile trip for labor day holidays, and after five hours during the returning home leg and while on cruise control at night, then without any notice the engine just stopped running/producing power at 60 mph and truck coasted to a stop.  There was no engine life but would crank and did not start or even show any signs of firing.  Immediate checks of fuses determined that there were no blown fuses.  Just to be sure I replaced fuse #41 for EGM but this did not help.  Luckily, I was 7 miles from home and got towed by a friend to house - whew!.  This morning, I checked engine codes and retrieved a P2509, ECM/PCM intermittent power and an intake low voltage code which, I cleared and these did not return upon several crankings of the engine.  No other electrical issues or instrument indications provide any further symptom identification.   I also unscrewed and checked the fuel filter housing to check for fuel and it was full as well as I can hear the fuel pump runing during the the ignition switch being first turned on.  I will empty it next and watch it refill to verify fuel is being pumped from the tank too.  So my initial thoughts are that for such a sudden (without symptoms or warnings) engine to cease running there must be an electrical issue of some sort.  I don't believe the ECM is without power or ground (initial assumption), since all wiring looks good and the batteries are both in good standing, but I plan to pull PCM connector and follow continuity checks per P2509 troubleshooting steps.  This truck has no maintenance history problems, with the exception when I washed engine compartment and got fuel rail pressure sensor connection wet and it went bad causing loss of power and surging symptoms.  With this experience and all the research during that trouble shooting effort, I initially thought the FCA was going bad and purchased one to have on hand before I narrowed down the problem to the fuel rail pressure sensor via consistent associated engine fault codes.  So, I am already at a loss for where to go if the PCM continuity checks are ok, which I fully believe will not be an issue???  Is it reasonable to believe a faulted FCA could cause shutdown of the engine suddenly?   ...or could the fuel pump itself fail suddenly like this also??? Any other trouble shooting leads will be welcome.  Thanks.

 PS - War Eagle it would be helpful if you can give me any insight into your CPS failure and whether the shop identified any related codes or did you have a code reader at the time and verified that there were no codes???  This would be very helpful and provide the logic I am looking for to confirm that this is a suspect component failure next.  Thanks, and btw I have the new COV and would like to just put it in and get immediate feedback, but will test its output from the current one installed before removing to inspect and replace it out ... in the spirit of being disciplined to following thru with the logical testing that my troubleshooting thoughts and plans are directing ...lol.!

I was dead on the road (out of town and out of state) and didn't have a reader with me at the time but had the truck towed to a shop.  They diagnosed and replaced the cam position sensor and I was on my way.  I didn't ask them about the code it threw (if any) but I believe 0340 is the likely code. 

 

Also, it is my understanding the the crankshaft position sensor can also cause similar symptoms if it goes bad. Likely code for that is 0336 I believe.

 

You can check for loose connector or damaged or loose wiring near the sensors.

By the way you are a man of great patience, I could not hold in my hand the part that may resolve an issue in the name of proper diagnosing, God bless!

Agreed! This is excellent reading for anyone who may find themselves found on the road dead.

I was recently trying to diagnosis a stumble/misfire issue with my sons F150. I found a good forum on ford trucks and a knowlegable person there was having a lengthy argument over the cause/symptoms of the issue. The guy was matter of fact that a faulty coil pack is the #1 culprit. The next day I bought every part that could possible cause this issue, and decided to heed his advice first.. Nailed it the first time and returned about $150 bucks worth of parts to the store.

Guys who post information like this do an invaluable service for the rest of us.

Ed,

 

Thanks for offer but that  link I provided ( Relentless Diesel • View topic - DIY CP3 Mods ) has pictures of how the internals of the FCA look and sequenced into its housing, which I was able to deduct valve positions when energized verse de-energized - super helpful.  It does throw a wrench into things about why the engine runs with FCA disconnected and does not shutdown verses starting/running the engine from ignition sw ACC position as you and I discussed previously that the engine shutsdown within 5 or so seconds?   What is going on that makes this difference?

 

It may not matter much other than I would like to understand what is going on, but I do believe your suggestion that the COV is the issue does make sense, as I do get the P0088 code during both starting condition (i.e., FCA connected and FCA not connected).  So this week end I am looking downstream at the COV and return fuel flow.  The only other inputs to cause the no start are other sensor inputs to the ECM, all of which I can not understand why they would not throw their own code, and cause a P0088 code too???   Hopefully, all this logic nails the COV being the failure, and I got the new COV part in the mail along with the fuel injector line blocking tool, and two banjo bolts (one with a gauge connection tap) and the banjo washers you suggested I have on hand to reseal any banjo bolts being removed.  I will at least have some more data to ponder .... or a smoking gun!!  I will post the results after working on it as I am planning on it tommorrow.

Edited September 25, 20159 yr by gudge

Well, troubleshooting today determined that the COV is operating correctly, fuel flow verified to flow from CP3 while cranking, and so I removed COV for inspection.  The piston slides smoothly under constant spring pressure, no hang ups or limited travel issues.  So my focus shifted to the fuel rail pressure sensor since it is producing the only (P0088) code.  I unplugged the sensor and tried starting the truck, which it started with no problem - although it was running rough (to be expected), and I got a P0192 code, "Fuel Rail Pressure Sensor Low".  So to recap: I can start the truck from ACC ign. sw. pos., but engine dies (get a P0088 code); I can start engine with FCA disconnected (get P0088 and P0251 codes); and, I can start engine with fuel rail pressure sensor disconnected (only get a P0192 code and no P0088 code (very interesting!)).  Since I have tested the FCA and determined it is good (and the old FCA too), I believe the problem lies with the Fuel Rail Pressure Sensor.

 

I still had the previous failed pressure sensor that I replaced in May this year (due to rough running, surging, no power when driving  - P0192 code).  So I reinstalled the old failed sensor and with the FCA connected started the engine with no problem and of course got the expected P0192 code and no P0088 code.  So my conclusions are that the new Pressure Sensor has failed-high, hence why I can not start engine with FCA connected and when I do start engine I am getting a P0088 code all the time. Therefore I believe the new Pressure Sensor has failed - high.  I decided to take continuity readings of both pressure sensors: the fail - low one has no continuity across any of the three connectors (makes sense since it gives a P0192 code, as well as I get this code when starting/running engine with the pressure sensor disconnected); and, the newer pressure sensor has a continuity reading of approximately 35 Ohms across the 2nd and 3rd connector stabs when looking at the end of the connector with the ***/key side upward.  Therefore, I plan to check on whether my newer pressure sensor is under a warranty (premature failure) and/or make a purchase of another replacement rail pressure sensor.  I will post the final verification that this is the fix to my problem, and also try to share some of my drawings then too. 

Edited September 27, 20159 yr by gudge

Well, troubleshooting today determined that the COV is operating correctly, fuel flow verified to flow from CP3 while cranking, and so I removed COV for inspection.  The piston slides smoothly under constant spring pressure, no hang ups or limited travel issues.  So my focus shifted to the fuel rail pressure sensor since it is producing the only (P0088) code.  I unplugged the sensor and tried starting the truck, which it started with no problem - although it was running rough (to be expected), and I got a P0192 code, "Fuel Rail Pressure Sensor Low".  So to recap: I can start the truck from ACC ign. sw. pos., but engine dies (get a P0088 code); I can start engine with FCA disconnected (get P0088 and P0251 codes); and, I can start engine with fuel rail pressure sensor disconnected (only get a P0192 code and no P0088 code (very interesting!)).  Since I have tested the FCA and determined it is good (and the old FCA too), I believe the problem lies with the Fuel Rail Pressure Sensor.

 

I still had the previous failed pressure sensor that I replaced in May this year (due to rough running, surging, no power when driving  - P0192 code).  So I reinstalled the old failed sensor and with the FCA connected started the engine with no problem and of course got the expected P0192 code and no P0088 code.  So my conclusions are that the new Pressure Sensor has failed-high, hence why I can not start engine with FCA connected and when I do start engine I am getting a P0088 code all the time. Therefore I believe the new Pressure Sensor has failed - high.  I decided to take continuity readings of both pressure sensors: the fail - low one has no continuity across any of the three connectors (makes sense since it gives a P0192 code, as well as I get this code when starting/running engine with the pressure sensor disconnected); and, the newer pressure sensor has a continuity reading of approximately 35 Ohms across the 2nd and 3rd connector stabs when looking at the end of the connector with the ***/key side upward.  Therefore, I plan to check on whether my newer pressure sensor is under a warranty (premature failure) and/or make a purchase of another replacement rail pressure sensor.  I will post the final verification that this is the fix to my problem, and also try to share some of my drawings then too. 

Gudge,

This has been an excellent read. Rail pressure sensors are pricey.  Its sounds like some bad luck, you have had one fail low, and now seem to have a newer one fail high in such a short span. I hope this is the final answer? If so you now have the readings (ohms) and symptoms of rail sensor failures to either extreme. It would be great if you could post the resistance readings from your new sensor just for future reference.

Good luck! 

Gudge,

This has been an excellent read. Rail pressure sensors are pricey.  Its sounds like some bad luck, you have had one fail low, and now seem to have a newer one fail high in such a short span. I hope this is the final answer? If so you now have the readings (ohms) and symptoms of rail sensor failures to either extreme. It would be great if you could post the resistance readings from your new sensor just for future reference.

Good luck! 

Ok, I will do this for use with others to troubleshoot the sensor in a static mode - sure will help verify than trial and error approach most of us if not all have to perform along the way.  

I called US Diesel Parts where the pressure sensor was purchase in May 2014 and discussed the warranty for the premature pressure sensor failure.  They were helpful and let me know that it should be covered, but it will have to be sent back to Bosch for failure verification and warranty processing.  Based on them giving me this assurance and not being able to wait the number of weeks all this is going to take, I went ahead and ordered the new pressure sensor.  US Diesel Parts will then reimburse me the cost of the new part when Bosch verifies the failure.  I would like to believe that Bosch will use this data in the betterment of the next generation of pressure sensor parts for improved reliability and in the end, all of us diesel customers may benefit (one day?).  However, I look forward to taking the continuity readings on the new pressure sensor for critical baseline data that will help the rest of us NOW, as an effort to greatly improve the efficiency of diesel troubleshooting and testing for sensor failures!.  

Edited October 1, 20159 yr by gudge

I was dead on the road (out of town and out of state) and didn't have a reader with me at the time but had the truck towed to a shop.  They diagnosed and replaced the cam position sensor and I was on my way.  I didn't ask them about the code it threw (if any) but I believe 0340 is the likely code. 

 

Also, it is my understanding the the crankshaft position sensor can also cause similar symptoms if it goes bad. Likely code for that is 0336 I believe.

 

You can check for loose connector or damaged or loose wiring near the sensors.

Thanks, I thought there may be a code set for this type of failure.  This rules out my situation, but I checked the wiring closely for the benefit of knowing its condition.  

With all the information you have collected through this experience.  If this scenerio were to play out again for a person stranded on the side of the road I can see where possibly disconnecting the rail sensor could allow someone to at least limp their truck home, and have a better than average starting point to trouble shoot from.

With all the information you have collected through this experience.  If this scenerio were to play out again for a person stranded on the side of the road I can see where possibly disconnecting the rail sensor could allow someone to at least limp their truck home, and have a better than average starting point to trouble shoot from.

I would agree, it is now cataloged well within my memory.  I believe you could do the same for the FCA too.

 

By the way you are a man of great patience, I could not hold in my hand the part that may resolve an issue in the name of proper diagnosing, God bless!

Ed, it is all about learning for me since I don't have much experience with diesel engines, much less Cummins.  I appreciated your help!

Received the new Rail Pressure Sensor from US Diesel Parts Monday evening, and started trying to obtain static measurements.  After a little while of getting mixed results, I started researching the sensor operation and determined the continuity checks do not provide any useful information (Sensor operation is based on piezio crystal converting pressure to voltage - I believe to be correct by deduction of studying the diagrams, electrical prints and reading operation description).  It appears I need to connect it to the computer and take voltage readings and/or ground readings.  Therefore, I will test all three Rail Pressure Sensors connected to the ECM to get the failure data from the two and the good data from the new sensor.  There are three leads with the sensor: a 5vdc reference, a ground (from ECM), and a variable voltage output based on pressure.  I will test it at zero pressure (which should correlate to .5 vdc output).  Hopefully, truck will be back in service this week end and share the data for each sensor (i.e., the failed low one, failed high one, and the good sensor).

Edited October 7, 20159 yr by gudge

Yes we should have already considered this..the rail sensor actually communicates with the ecm via the data network. It is not simply a resistance value as found on older vehicles. When connected the pressure sensor has what is refered to as a source address. The ECM is programed and sees the sensor by this source address and translates the voltage reading into useful information.

 

I just had to go back and edit this post.. The sensor communication is not as complex as what you would see between an ECM and another control module.

Edited October 9, 20159 yr by angus

Success Proclamation: Problem Fixed!!! ...Eureka

 

Ok, I see this clearly now Angus, which my troubleshooting was driving me to understand the sensor operation more in detail in order to test the Rail Pressure Sensor correctly for confirmation of failure.  My troubleshooting had shifted toward this component (others can see from the above steps, analysis, questions, and thoughts - thanks to all) as the root cause of my truck shutting down while driving at 60 mph on cruise control with NO symptoms, NO engine light, NO noises, No electrical perturbations, NO nothing, but silence while coasting to a stop at night and then essentially a crank/no start condition.

 

Well, I tested all three Rail Pressure Sensors (RPS) by connecting them to the ECM via the normal connector (uninstalled) and took the voltage reading from the center connector (Fuel Rail Sensor Signal).  I found where Bosch/Cummings provided the signal expected output from the RPS to the ECM (i.e., .5 vdc - 4.5 vdc for a corresponding 0 psi - 26,107 psi) so this allowed me to know what I was looking for from each of the three sensors:  the original failed low (P0192 code) sensor which should be very low/no voltage output; the existing failed high (P0088 code) sensor which should be a much higher than .5 vdc output; and, the new sensor just recieved which should be .5 vdc at 0 psi if it is working properly without any problems).  The results of the data acquired were almost precisely what would be expected for each condition:

• The original failed low sensor (P0192 code) output measured .01 vdc
• The existing failed high sensor (P0088 code) output measured 2.84 vdc (this output corresponds to approximately 15,000 psi fuel rail pressure)
• The new sensor output measured .5 vdc as it is designed and specified to provide for 0 psi

These measurements were all expected based on my troubleshooting narrowing down that the RPS had failed, not the FCA, not the COV, not the ECM, etc...!!!!!!  It can be easily seen that the measured outputs correspond to the failure codes received, and the new sensor output is as specified (EXACTLY) by the manufacturer.

 

In retrospec, the initial codes that I got (P02509 and one for low intake voltage/#?) were misleading, and I may have caused them via trying to trouble shoot on the side of highway and/or possibly due to my weak/8 yo batteries?  But after reading these codes, and then clearing them the next morning with my code reader, they never returned again thru all my other troubleshooting, ...and then when I finally stumbled on to being able to start the truck and initially get it to run although only for a brief period (i.e., from the ACC ign. sw. position), the p0088 code has been central to all the other start/run configurations since (except when the RPS is disconnected from ECM as would be expected).  However, I still can not answer why the truck would not start/run from the On ign. sw. position, but would start/run and then die from the ACC ign. sw. position?  I believe now it was the ECM shutting down/cutting off fuel from the fuel injectors (i.e., no fuel allowed to enter cylinders) with the overpressure signal (i.e., from the failed RPS), since because from what has been learned about the FCA when its valve is seated fully closed by spring pressure (i.e., the solenoid is not operating/ECM demanding less fuel rail pressure) there should have been enough fuel emitted (i.e.,  the FCA valve seated fully closed by spring pressure would still allow idle fuel flow to the CP3 due to the small end of the triangular shaped valve opening "always" allowing idle fuel flow when the FCA valve is fully seated closed -see excellent web page link above with pictures of FCA internals).  Other important learnings are that the truck would start/run with the FCA disconnected, and it would also start/run with the RPS disconnected from the ECM, an important future trick to use and limp yourself home!  If I had this knowledge that "dark" night, it would have potentially allowed me to run/limp the truck home without tow ...I did not test moving the truck during my troubleshooting in these configurations so this can not be affirmed but there was a steady idling engine, and if I remember correctly there was throttle capability at least with the RPS disconnected. Additionally, the COV was a potential issue and could have been a strong suspect, but it is very easily troubleshot by removing it and mechanically inspecting its operation ( i.e., by pushing valve its length of travel (smoothly) with a small diameter shaft).  Lastly, the FCA is really just a very simple solenoid device/mechanical valve and its testing can be determined by operating it in hand while connected to the ECM (it also throws codes that should help with identifying its failure).  

 

I hope all this recap helps others for now and while I got the family back on the road pulling horses around, as time permits I will try to get my notes and diagrams ironed out for posting.  These should top-off this whole episode as my final sign-out.  Lastly, thank you to all for your inputs and thoughts, which have helped educate me into becoming a diesel troubleshooter or at least allowed me to grow knowledge and have an appreciation for the all mighty diesel engine design and operation!  Please feel free to correct me on anything that is not correct or could use clarifications, as these posts are meant to help others ...and that may well mean me again, too!?? 

Edited October 10, 20159 yr by gudge

Hallelujah brother. Happy to see you got it fixed. That is whole lot more electronics trouble shooting than I would want to mess with. But I am happy you got it fixed.   

Hallelujah brother. Happy to see you got it fixed. That is whole lot more electronics trouble shooting than I would want to mess with. But I am happy you got it fixed.   

Thanks - cheers all the way around; these man made machines are a blessing and a curse at times!  I was a Navy ET (many years ago with tube/transistors) and have held an Extra Class Ham license ever since, fiddled with avionics, antennas, etc... but it is always a challenge that keeps me perplexed most of the time - like flying in the clouds until you breakout into sunlight.  I can't deny it being worth celebration over a beer or two though.  Now on to working with Bosch via US Diesel Parts guys to refund me the part cost under its warranty and believing maybe improving the parts reliability.  This RPS only lasted 4K miles over a 6 month period?

How did you go about testing the sensor?   Did you back probe the harness?  I don't like breaking the insulation.  A way for contaminates to start corroding the wires. I've used a sewing needle to put as small a hole as possible in the insulation.