What does SPN 520501 FMI 7 (520501/7) mean?

Wheel Speed Permanent Slip Failure at Axle 1 Left: mechanical system not responding.

What does SPN 520501 FMI 9 (520501/9) mean?

Wheel Speed Permanent Slip Failure at Axle 1 Left: abnormal update rate.

SPN 520501 — Wheel Speed Permanent Slip Failure at Axle 1 Left (Meritor (ex-WABCO))

Q: Can I keep driving with code SPN 520501 (Wheel Speed Permanent Slip Failure at Axle 1 Left)?

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

Safe to driveUntil the next service

SPN 520501 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by Meritor (ex-WABCO), and what the second half of the code (FMI) means.

Meritor (ex-WABCO)

FMI 7	Wheel Speed Permanent Slip Failure at Axle 1 Left
FMI 9	Wheel Speed Jump Down Detection at Axle 1 Left
FMI 13	Impermissable Tire Size Detected at Axle 1 Left
FMI 14	Impermissable Deviation of Tire Size Detected at Axle 1 Left

What FMI means in J1939

SPN 520501 FMI 7520501/7 · 520501.7	mechanical system not responding
SPN 520501 FMI 9520501/9 · 520501.9	abnormal update rate
SPN 520501 FMI 13520501/13 · 520501.13	calibration out of range
SPN 520501 FMI 14520501/14 · 520501.14	manufacturer-specific instructions

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: Until the next service

A standalone fault with no immediate consequences for driving.

Show the codes at the next service. If a second code from the same system appears, stop putting it off.

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.