
Table 19
Diagnostic Trouble Codes for the DPF Differential Pressure
J1939 Code
Description
Notes
3251-7
Particulate Trap Differential Pressure : Not Responding Properly The Electronic Control Module (ECM) detects the following
conditions:
The measured differential pressure from the DPF differential
pressure sensor is invalid.
The battery voltage is at least 10 VDC.
This fault can be caused by damaged or blocked pipes to the
DPF differential pressure sensor.
If equipped, the warning lamp will come on. The engine will be
derated.
3251-10
Particulate Trap Differential Pressure : Abnormal Rate of
Change
The ECM detects the following conditions:
The differential pressure across the DPF does not drop below
2.5 kPa (0.36 psi) after the engine has stopped.
This code will be active when the defect has been detected for
at least 6 seconds.
The battery voltage is at least 10 VDC.
If equipped, the warning lamp will come on. The engine will be
derated.
3251-17
Particulate Trap Differential Pressure : Low - least severe (1)
The ECM detects the following conditions:
There is no differential pressure across the DPF for at least 100
seconds.
The battery voltage is at least 10 VDC.
The engine will be derated.
The fault will be cleared if the differential pressure is within the
acceptable range for at least 10 seconds.
3251-18
Particulate Trap Differential Pressure : Low - moderate severity
(2)
The Electronic Control Module (ECM) uses the Diesel
Particulate Filter (DPF) differential pressure sensor to
monitor the soot load in the DPF. An excessive
accumulation of soot in the DPF can be caused by
the following faults:
Probable Causes
• Diagnostic codes
• Exhaust leaks
• Connections to the DPF differential pressure
sensor
• Incorrect installation of the DPF
• Faulty DPF differential pressure sensor
Recommended Actions
Note:
The procedures have been listed in order of
probability. Complete the procedures in order.
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UENR0612
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