Global SCR Fault Code
Free · no signupSPN 3216 FMI 13 / 20
Intermittent Check Engine Light; Sudden derate; Inconsistent emissions data.
System
Not specified
Symptom
Intermittent Check Engine Light; Sudden derate; Inconsistent emissions data.
Diagnosis & fix steps
Inlet NOx Sensor - Drifted High / Out of Calibration.
LOGIC: The sensor's ceramic element is "poisoned" or aged, causing it to send a signal that doesn't match engine mapping.
ACTION: 1. Inspect sensor wiring for heat damage.
2. Check for moisture in the sensor control module.
3. Perform a "NOx Sensor Reset" in the software.
FIX: Replace the Inlet NOx Sensor and its associated control module.
Red Seal field insights
NOx sensors are "smart" and talk over the CAN bus. If you have multiple sensor codes, check the power and ground to the sensor module first. They often fail due to vibrations in the exhaust mounting.
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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