Case Fault Code
Free · no signup9401
No Regeneration.
Variant 1
System
Not specified
Symptom
No Regeneration.
Diagnosis & fix steps
LOGIC: DPF Temperature Sensor #1 Error.
ACTION: Check the temperature sensor probe for soot "insulation" or a broken wire.
Red Seal field insights
Red Seal Fix: These small rigs don't get hot enough if they just sit and idle. If the sensor is covered in soot, it can't read correctly. Take it out and clean it with a soft wire brush.
Variant 2
System
Emissions (DPF)
Symptom
Power Loss.
Diagnosis & fix steps
LOGIC: DPF Differential Pressure Sensor reading is abnormal.
ACTION: Check the two sensing tubes for moisture or ice (common in Ontario winters).
Red Seal field insights
Red Seal Fix: If the tubes are clear, the sensor is likely "slugged" with soot. Blow the lines out away from the sensor with low-pressure air (5 PSI) to avoid popping the sensor diaphragm.
Track this across your whole fleet
This code is free to read. AM Fleet Integrity lets your team log fault codes against assets, plus the full fault-code library, QR operator reporting, PM scheduling and predictive alerts. Start free — no credit card required.
Start your free trial