SPN 3216 engine fault code indicates after treatment 2 intake NOx problem. A FMI 20 means data drifted high as shown in data table:
SPN, FMI – Fault Code Meanings:
- 3216, 2 – data erratic
- 3216, 4 – low voltage or shorted
- 3216, 9 – abnormal update rate
- 3216, 10 – abnormal rate of change
- 3216, 13 – out of calibration
- 3216, 16 – above operating range
- 3216, 20 – data drifted high
Suggested Fix:
The inlet NOx sensor is a device that connects to the ECM. You can replace it, or recalibrate the ECM.
