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DR.Cummins
DR.Cummins, FIELD SERVICE TECHNICIAN
Category: Heavy Equipment
Satisfied Customers: 3628
Experience:  16 Years working on Cummins Diesel engines,
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I got a peterbuilt with a cummins isc it was giving me a

Customer Question

hi i got a peterbuilt with a cummins isc it was giving me a check engine light and then a stop engine light so the mechanic went into the ecm and it said high crankcase pressure so the guy replaced the crankcase filter and sensor we cleared the code and the check engine light keeps coming back on we just checked it through the ecm and it says high engine pressure it is inactive when the light is off but it keeps coming on even after we cleared the code
JA: What is the complete model and serial number of your machine?
Customer: px8 286 73010064
JA: Anything else you want the equipment mechanic to know before I connect you?
Customer: just that we clear the code and it keeps coming on check engine
Submitted: 5 months ago.
Category: Heavy Equipment
Expert:  DR.Cummins replied 5 months ago.

Are/were there any other codes present in the ecm inactive?What is the fault code number

Customer: replied 5 months ago.
no
Expert:  DR.Cummins replied 5 months ago.

Was it a 555 fault code or 556 ?

Customer: replied 5 months ago.
it was neither of those codes im not sure i think it was fmi 0
Customer: replied 5 months ago.
when we unplugged the sensor we got pid 101 fmi4
Customer: replied 5 months ago.
when we plugged it back in we got fmi 0
Expert:  DR.Cummins replied 5 months ago.

These are the Cummins codes that are for high crankcase pressure. The FMI is a OEM code and I convert it to Cummins. see below. Since you said the stop engine light came on ill go with fault 556 The ECM illuminates the red STOP ENGINE light when the crankcase pressure limit is exceeded.

CODE

Fault Code: 556
PID: P101
SPN: 101
FMI: 0/0
LAMP: Red

Crankcase Pressure - Data Valid but Above Normal Operational Range - Most Severe Level.

Ill give you a list to check

Customer: replied 5 months ago.
yeah but we put a new filter in and sensor we have not gotten a stop engine since just check engine which is yellow
Expert:  DR.Cummins replied 5 months ago.

Now I do see an update in the ecm calibration that fixes these codes too. It stops false occurrences the updated calibration is AU90115.20 but when Cummins updates the ecm it will be up to AU90115.36 so you may want to have the ecm calibration checked . But first you need to check the following

Possible causes of this fault code include:

  • Crankcase breather filter needs to be replaced --REPLACED
  • Crankcase pressure sensor damage ---REPLACED
  • Plugged or restricted crankcase breather oil separator
  • Plugged or restricted crankcase breather oil drain tube or check valve
  • Plugged or restricted crankcase breather draft tube
  • Frozen, plugged, or restricted crankcase breather tube.

If all the tubes are free and clear. You will need to have the unit ran on a dyno and check for high blowby (crank case pressure)

And this can be caused by:

Air compressor is malfunctioning

Turbocharger failure

Valve stem clearance is excessive or the valve stem seals or guides are damaged

Piston or piston rings are worn or damaged

Please don't forget to rate my service .

Expert:  DR.Cummins replied 5 months ago.

Here are the lines and separator you need to check . The check valve is built in to the lines

Customer: replied 5 months ago.
hi ratin very informative
Expert:  DR.Cummins replied 5 months ago.

Thank you.I'm always here if you need assistance.The accept /rate button will be lit now to accept . Thank you again

Expert:  DR.Cummins replied 5 months ago.

Hi just following up . Please don't forget to rate my service.

Expert:  DR.Cummins replied 5 months ago.

Please don't forget to rate my service

Expert:  DR.Cummins replied 4 months ago.

Hi, Just following up. Please don't forget to Accept/Rate my service.