P2047-1 Intermittent

cRoe04

New member
Hi everyone,
Just bought my first sprinter van, a 2008 with a OM462 engine. 222k miles on the chassis but the engine was replaced 50k ago. Here is my issue, when accelerating foot to the floor occasionally a check engine light pops and it loses most of the power. I can maintain 60 on flat ground but any slope and it slows rapidly. I am a long time Ford tech but this is Greek to me. The freeze frame data for two code pops
RPM 3440 3100
Quantity Control Valve 12.4% 14.0%
Rail Pressure Commanded 1518 bar 1511 bar
Rail Pressure Actual 1314 bar 1321 bar
I can generate 1500 bar if I am careful with the throttle and don't trip the DTC. I replaced the fuel filter as the first and easy check. Problem still happens. Tested low fuel pressure at idle 58 psi in and out of the filter so I don't believe that is the issue. However I do understand that the pump my be dropping out under heavy load, I will try to tape a gauge to the windshield and check pressure under load when I get a chance. There are no leaks that I can tell from any of the injectors and certainly no high pressure line leaks. The nearest Sprinter trained technician is over 200 miles away so I'd rather like to try and crack this nut on my own. Any guesses from the Mercedes gurus on here? Thanks for any help!
 

Dima74

Independent & Self Reliant - From Chattanooga TN
Have you tried to replace the quantity control valve?

2047 - [1] Rail pressure monitoring via volume control valve - The rail pressure is too low.

Part number below...
 

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manwithgun

Active member
As Dima says, the quantity control valve is an excellent place to start when chasing intermittent rail pressure faults. If your low pressure system is good, the high rail pressure is balanced between the pressure regulator on the drivers side rail AND the quantity control valve on the high pressure pump (based on rpm/demand). $150-200 and 30 minutes to swap out and no adaptation needed. Once the fan and shroud are out, it's just 3 bolts, plug and play. 36mm nut on the fan is reverse thread. Poor pin continuity to/from the rail pressure components can cause similar issues.

EDIT: Examples of rail pressure faults "possibly" cured by quantity control valve.
Standard OBD scanner fault
- P0088 - Fuel rail/system pressure - too high
Autel AP200
- 2018-1 - Rail pressure monitoring via volume control valve - Rail pressure too high
- 2016-1 - Rail pressure monitoring via volume control valve - Rail pressure too low
 
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cRoe04

New member
Ordered and installed a new VCV. Can now accelerate to the speed limiter with no problems. Seems to be fixed! Thanks for the help
 

nctrailseeker

Active member
Please forgive me for hi-jacking the thread, but quick question. Does this quantity control valve also apply to the T1N ?
 

Dima74

Independent & Self Reliant - From Chattanooga TN

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