HI all, question, P0093 code. Seems everyone feels that code refers to sucking air or or lack of fuel. I am sure that is largely due to ODB II codes indicating this to be a "Large fuel leak". However, the 06 FSM does specifically say that it indicates "Positive fuel pressure deviation" and also says it means "Excessive fuel pressure above setpoint". So if we look at it from the pressure to high then it would seem like either the pressure control valve is off, or if that is known to be good, then the rail fuel pressure sensor is giving incorrect readings. Am I missing something hear? Would love to hear a response and thoughts on this subject. It would explain a lot about why some rigs shut down on that code with no apparent air in the system and plenty of fuel.

Mark

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2005 Jeep Liberty, GDE Ecotune, 31x10.5x15 with 3" Daystar Lift, Gabriel Struts and shocks.

usually means filter is plugged.....

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2006 Liberty CRD 275K, JBA 2.5 with Fox Shocks, GDE Turbo Kit, GDE TCM Tune, Suncoast TC, OEM fuel filter housing converted to fit Caterpillar Fuel Filter 1R-0749, OEM themostat housing modified to accept Hemi 203 F thermostat.

X2 on the plugged filter, or you have air in the lines, or out of fuel, I have had it a few times, but never the large leak.

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2006 LTD Bright Silver loaded with all the needed mods, CCV intact.
Proudly supporting CRD vendors, and their development of quality parts and accessories.
Equipped with HDS thermostat, plenty of heat, faster warm-ups, increased fuel mileage.

Just got P0093. Would get the CEL after hard accel/high revs (eg: merging). Changed the fuel filter and can't seem to replicate the problem again (fingers crossed).

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'06 CRD
Frankenlift II, 245/75/16 Goodyear MT/R's on Moabs, Samco Hoses, Provent, Mopar iPod Integration Kit

I had to replace the fuel pressure control solenoid on the back of the fuel pump. Took 1 hour and can be done without removing the timing belt

Rocky,

How did you determine that was the part to replace? Seems that code is pretty general.

DOC

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2005 KJ CRD Ltd Detroit TrueTrac Bilsteins G2 GDE "HOT" ECU GDE TCM "Tow Tune" "euro" TC SEGR Weeks Elbow New HG at 130K ARPs Clean CAT aFe Filter Magnaflow Exhaust EHM Cumminos In-Tank Lift Pump Hayden Fan Clutch Nylon Fan VH Enabled with GDE lower shutoff point Recalibrated Temp Gauge Tekonsha Prodigy Sears P-1 ZDDP

*Yes, I know this thread is old, but thought this info might help, as I couldn't find many actual solutions after searching*

I was getting the P0093 "large fuel leak" code and limp mode first while towing a trailer through the mountains doing 80. After that, it would pop into limp mode any time over 3/4 throttle. Checked for leaks, duh. Changed the fuel filter. The thing that fixed it for me was the Fuel QUANTITY Valve (not quality, as I have seen it written) on the back of the CP3. It's also called many other things for some reason, Fuel Pressure Regulator, Pressure Control Valve, Diesel Fuel Metering Unit, etc. Not hard to change with 3 bolts using a T25 tool. The part is BOSCH 0928400822 I found it cheapest (less than $100.) on ebay shipped from Latvia!?

Anyway, hope this helps someone. The code is not descriptive at all as to where to troubleshoot it.

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06 KJ Limited CRD
mod airbox
EHM
Mishimoto hoses
Weeks Stage1+2
Yeti stage 2 ECM
GDE ECO TCM
FTC billet TC
Transgo kit
no mech fan
Cummins lift pump
2.5" catback
OME 790/948 springs
JBA top plate and UCAs
2 upper rear insulators
Bilstein 24-139168 front 24-186704 rear
255/70R16
1.25" wheelspacers
SkidRow engine plate