SPN 91 FMI [2-19] Diagnostic Code Explained, Fix

SPN 91 is a diagnostic trouble code for accelerator pedal position 1 data erratic.

FMI 2 – Intermittent Or Incorrect
FMI 3 – Voltage Above Normal, Or Shorted To High Source
FMI 4 – Voltage Below Normal, Or Shorted To Low Source
FMI 8 – Abnormal Frequency Or Pulse Width Or Period
FMI 9 – Abnormal Update Rate
FMI 19 – Received Network Data In Error


APP sensor, check connections or replace
Verify ECM calibration


Other SPN codes: