SPN 3226 is a diagnostic trouble code for Aftertreatment 1 Outlet NOx.
FMI 2 – Data Erratic, Intermittent Or Incorrect
FMI 4 – Voltage Below Normal, Or Shorted To Low Source
FMI 9 – Abnormal Update Rate
FMI 10 – Abnormal Rate Of Change
FMI 13 – Out of Calibration
FMI 20 – Data Drifted High
NOx is nitrous oxide.
Troubleshoot:
NOx sensor and circiut to ECM, wiring harness
