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.
Same code keeps coming back?
That's a program problem, not a part problem. Book a 30-minute uptime review with Grant, a Red Seal Heavy Duty Technician.
Read before you touch anything
- This is general reference information, not a repair manual. It is for trained, qualified technicians.
- Fault codes, meanings and procedures vary by model, serial number and software version. Confirm the code and the procedure against the manufacturer's service manual before acting.
- Follow the OEM service manual, torque specs and your site's safety procedures: lockout/tagout, block raised equipment, relieve hydraulic, fuel and air pressure, and let hot systems cool.
- You use this information at your own risk. Adventure Mechanical and AM Fleet Integrity accept no liability for damage, injury, downtime or loss arising from its use.
- Not affiliated with or endorsed by any manufacturer. Brand names are used only to identify the equipment a code applies to.
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