Scania Fault Code
Free · no signup4097 (SPN 3216 FMI 20)
Frequent DPF regens; High DEF consumption; Power derate.
System
Not specified
Symptom
Frequent DPF regens; High DEF consumption; Power derate.
Diagnosis & fix steps
NOx Sensor 1 (Inlet) Drifted High.
LOGIC: The sensor is reading a higher level of NOx than the ECM calculates should be possible based on engine load.
ACTION: 1. Check for exhaust leaks before the SCR catalyst.
2. Inspect the sensor tip for white "crystal" (DEF) buildup.
3. Check the sensor module CAN wiring.
FIX: Repair exhaust leaks or replace the NOx Sensor.
Red Seal field insights
Scania NOx sensors are a common failure item. If you see white buildup on the sensor tip, your DEF injector may be "dripping" rather than "spraying," causing the sensor to give erratic readings.
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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