What does SPN 520240 FMI 3 (520240/3) mean?

SPN 520240: voltage above normal or shorted high.

What does SPN 520240 FMI 4 (520240/4) mean?

SPN 520240: voltage below normal or shorted to ground.

SPN 520240 — factory code MAZ, Meritor (ex-WABCO), SITRAK and others

Q: Can I keep driving with code SPN 520240?

Safe to drive. Below — how much time you have and what happens if you keep going.

Safe to driveDrivable, but watch it yourself

SPN 520240 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by MAZ, Meritor (ex-WABCO), SITRAK and YaMZ, and what the second half of the code (FMI) means.

MAZ Meritor (ex-WABCO)SITRAK YaMZ

MAZ

FMI 3	Cruise control indicator lamp circuit fault - Short to ground. Blink code: 3-3-6. Repair: Check the cruise control indicator lamp and its wiring.
FMI 4	Cruise control indicator lamp circuit fault - Short to battery positive. Blink code: 3-3-6. Repair: Check the cruise control indicator lamp and its wiring.

Meritor (ex-WABCO)

FMI 9

External Brake Request, Message Timeout

SITRAK

FMI 8	The torque-to-fuel-quantity conversion map is not strictly monotonic. Scan tool code: P1031. Effect: Torque may be limited.
FMI 13	The torque-to-fuel-quantity conversion map is not strictly monotonic. Scan tool code: P1031. Effect: Torque may be limited.

YaMZ

FMI 3	Cruise control indicator lamp circuit fault (Short to ground). Blink code: 3-3-6. Repair: Check the cruise control indicator lamp and its wiring.
FMI 4	Cruise control indicator lamp circuit fault (Short to battery positive). Blink code: 3-3-6. Repair: Check the cruise control indicator lamp and its wiring.

What FMI means in J1939

SPN 520240 FMI 3520240/3 · 520240.3	voltage above normal or shorted high
SPN 520240 FMI 4520240/4 · 520240.4	voltage below normal or shorted to ground
SPN 520240 FMI 8520240/8 · 520240.8	abnormal frequency or pulse width
SPN 520240 FMI 9520240/9 · 520240.9	abnormal update rate
SPN 520240 FMI 13520240/13 · 520240.13	calibration out of range

Can I keep driving

Safe to drive. Below — how much time you have and what happens if you keep going.

What happens if you keep driving

Time you have: Drivable, but watch it yourself

This is an electrical fault: an open, a short or a bad contact in the sensor circuit. The value it measures is most likely fine.

You can drive. But until the circuit is repaired this system runs blind and cannot warn you about a real failure.

Nearby: other

Scanner threw several codes at once? Paste the whole list — we will show which one is the root cause and which ones simply followed.