SPN 520257 — Trailer detection sensor faulty (SITRAK and Volvo)

Safe to driveUntil the next service

SPN 520257 is a manufacturer number outside the standard J1939 table: different makes can put different things under it. Below — how it is worded by SITRAK and Volvo, and what the second half of the code (FMI) means.

SITRAK

FMI 2	Implausible temperature sensor reading at cold start, combination 4. Scan tool code: P1004. Effect: Fan and warm-up control may misbehave.
FMI 8	Implausible temperature sensor reading at cold start, combination 4. Scan tool code: P1004. Effect: Fan and warm-up control may misbehave.

Volvo

FMI 12

Trailer detection sensor faulty, open or short circuit in the wiring harness.

What FMI means in J1939

SPN 520257 FMI 2520257/2 · 520257.2	data erratic or intermittent
SPN 520257 FMI 8520257/8 · 520257.8	abnormal frequency or pulse width
SPN 520257 FMI 12520257/12 · 520257.12	faulty device or component

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

• SPN 520252
• SPN 520253
• SPN 520254
• SPN 520255Light switch pulled for more than 60 seconds
• SPN 520256LCM output current to the interior lighting lamps is below 500 mA
• SPN 520258LCM output voltage is equal to or higher than the LCM supply voltage
• SPN 520260Actual CFV floor pressure above target value
• SPN 520290
• SPN 520310Exhaust gas temperature 1 below the lower plausible range limit
• SPN 520392SMU hardware monitoring module

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