P0093, Limp Mode
 

Hello, Just joined DB in the hopes that someone here might be able to offer additional insight into the problem with my 05 2.8 liberty CRD with 80k miles. I will try to keep the description brief, but with all the details.

This problem started as intermittent over several months. I thought it was fuel filters as I would replace them and it would be fine for a bit, until one day on a 300 mile trip I stopped near the end for fuel. after I left the station It went into what I now believe to have been limp mode and I stopped and replaced the fuel filter thinking I got bad fuel, but no change. Would die under any load, but would start and run fine right away, but with no power, 50 mph tops and 30+- on hills. Fine the next day. Shortly after that the problem was continuous after 5 min warm up. Runs fine with full power during 1st 5 min while cold.

I have ran the gamut. Original codes were intermitant P0093, and continuous 401 and 299 for Low turbo boost and EGR. I cleaned the boost/air temp sensor as well as MAF and Map and replaced original fuel filter head with aftermarket. Added 10 psi electric lift pump and installed 2' of clear fuel line in a loop after filer head to insure air free system. Pulled CAC hoses for inspection and cleaning. I ended up replacing the EGR as those codes were continuous. After EGR was replaced, no more code 401 or 299. However that was when the P0093 started being set continuously.

I have done all the checks for Fuel quantity solenoid (MPROP) the Fuel pressure solenoid (Pressure regulator), Air flow valve, wiring, and Turbo control. All research indicates the Fuel quantity solenoid fails more often and so that was the first valve I replace. No change, then the Fuel pressure solenoid was replaced and still no change. No additional codes that were not due to things I did and they went away never to return.

P0093, depending on who you chat with and what source one is looking at, it can indicate either high pressure or low pressure in the fuel rail. So going back to the original symptoms of being heat related (runs fine cold) does not fail until after a 5 min warm up, tells me the system is capable of building and running full system fuel pressure, something is amiss to send it into limp mode. Runs fine, just no power thus limp mode, dies completely under load, but will immediately restart fine, can anyone suggest what I should check now. My next step is to double check wiring and connectors and retest the pressure sensor hot and cold. How would I verify if the ECM is actually faulty?

I purchase the 05 manuals on disk a long time ago, but I recently downloaded the 06 off of Lost Jeeps so I have all that information. I don't know if DB has a link for a similar page.

Thanks to who ever reads this for your time. :argh:

Mark

Have read your lines and do recommend the check of the supply lines.

As you might have read in the other thread P0093 can be a couple of faults. I would like to cross check withan other source, but this will take a couple of days.
I also would like to have a close look at the wiring first, since the manual gives a bunch of fault recommendations. Most of them are wiring related. If the ECM is damaged you must face serious costs, since the Skim does not allow an easy interchange of ECM's.

So do check the wiring bit by bit. Disconnect the loom at the sensors and at the relay. Measure between and against ground. before doing this make sure the battery is disconnected.
Do you have theto be expected resistor values? If so cross check the exchange or old relay too to get variances.

I do report back. Deezel
There is a reason to list the errors in an order. start to check from top to bottom it usually starts with the most expected or with the cheapest error.

Thanks for the help. Yes the manual gives the values for the items dealing with a P0093 and will go through them again. Also know that some parts can fail without setting a code for something related to that part. I checked the values on the Fuel Pressure Sensor today. Tests were at unloaded conditions and were within specs when cold. After 20 minutes of idle ran the checks again and were pretty much the same, maybe a little diff under initial full throttle but still in the mid 3.5 volt range for a moment then settling into the 2.5 volt range.

After reading some other threads I am wondering if a defective boost/air temp sensor may be a factor. I am trying to think back as to when the 93 code became constant. I cleaned that sensor as it was gunked up with oily soot and it was not long after that that I replaced the EGR at which time the 93 became constant. I am just trying to reason out what might cause the limp mode and also the 93 code to pinpoint an area that might be the problem. I have a scanner but I don't have the big tools a dealer would have. Problem is my area dealer would most likely never have seen a jeep CRD to have any more experience than I have.

TM

Do not idle that engine. EGR is full open during idle. The no load condition is very bad for the engine.
As I told you I'm going to cross check this with my friends.
Soot build up, caused by the EGR and oil mixtures, is one of the biggest problems with this engine.

Just an update, doing what I can as I think of it. Checked the coolant temp sensor and no problem detected and not change. I tried running it with the temp sensor unplugged and still went into limp mode, however just ran without power and did not die. plugged it back in and cleared the temp codes and then it dies under power again.

Originally when the new filter head was installed I left the heater puck connect to the side as there is not a fuel heater or fuel temp sensor in the new fuel head. I ordered an Omega fuel temp sensor and installed it today. No change, still runs fine cold and goes to limp mode after warm up and sets a 0093 code. So back to more research
:humm:

problem solved yet/

Just to update everyone. The problem still persists. It is definitely temp related. Runs fine cold. Limp mode after warm up. I sent the PCM to Keith at Green Diesel Eng. who also has an 05 CRD. He installed the computer into his CRD and it ran fine. So, no problem with the computer. I got it back and problem still persists. So still doing research at this point, just is going slow.

0093, 0102, 0101, 0234 codes
 

2006 liberty 2.8 CRD limp mode, go passing gear, limp mode, shut it off, restart, out of limp mode, than again n again. Removed my tank held open the spring on the filler valve so can pour out the fuel, cleaned out the rest with clean rags..washed the float basket with diesel.Was a fare amount of crap including a small paper bottle cap liner. Oiled the big green o ring put it back to geather....took it for a run went into passing gear ok on a hill, ran the hill a few times. run it up to 180 km aprox 110 miles per hr. only for a few seconds. All was ok. Will check it again tomorrow. I did not think this would be the problem, but maybe it was.
Countrybumpkin

:tu:
Try to get a new O-ring. They start to leak once removed.

ready to sell
 

Tulmaster...i have the same problems with my 06 crd as you ...I am ready to sell...have you solved your limp mode and change filter just to start?...I will miss this crd!