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SPN 84 — Wheel-Based Vehicle Speed

Do not driveTo the nearest safe stop

J1939 code SPN 84. Below — how the fault is worded at the factory by DAF, Dongfeng, Ford Trucks, Foton, International, KAMAZ, MAZ, Mercedes-Benz, Renault Trucks, SITRAK, YaMZ and ZF AS-Tronic, and what the second half of the code (FMI) means in the standard.

DAFDongfengFord TrucksFotonInternationalKAMAZMAZMercedes-BenzRenault TrucksSITRAKYaMZZF AS-Tronic

DAF

FMI 2Vehicle speed signal missing/implausible
FMI 10Abnormal rate of change of speed signal frequency
FMI 18Speed signal corrupted

Dongfeng

FMI 2Loss of signal or incorrect vehicle speed signal
FMI 10Vehicle speed signal not plausible (rate of change)

Ford Trucks

Ford Trucks/Ecotorq writes fault numbers in its own format: the code in the table below is a Ford code (hexadecimal, zero-padded), not a J1939 SPN. It matches the standard only where the signal itself is standard, and usually matches the title of this page by digit alone.

FMI 0MAF Sensor – Inconsistent High Reading. FODP code (scan tool): P0101-22.
FMI 1MAF Sensor – Inconsistent Low Reading. FODP code (scan tool): P0101-21.
FMI 5MAF Sensor Electrical – Open / Short Circuit. FODP code (scan tool): P0103-01.

Foton

FMI 9Vehicle speed signal missing

International

FMI 9Wheel-Based Vehicle Speed — Missing Wheel Based Vehicle Speed Message

KAMAZ

FMI 0Vehicle speed measurement, path 1 (tachograph link!)
FMI 2Vehicle speed measurement, path 1 (tachograph link!)
FMI 3Vehicle speed (C3 or J1939). K-line code on KamAZ-5490: ADM3 10103.
FMI 9Vehicle speed (C3 or J1939). K-line code on KamAZ-5490: ADM3 10109.
FMI 11Vehicle speed measurement, path 1 (tachograph link!)
FMI 12Vehicle speed measurement, path 1 (tachograph link!)
FMI 14Vehicle speed (C3 or J1939). K-line code on KamAZ-5490: ADM3 10114.
FMI 19Vehicle speed (C3 or J1939). K-line code on KamAZ-5490: ADM3 10119.

MAZ

FMI 0Vehicle speed sensor fault - Maximum speed exceeded. Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.
FMI 2Vehicle speed sensor fault - Vehicle speed inconsistent with fuel delivery and crankshaft speed. Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.
FMI 11Vehicle speed sensor fault - Speed sensor coefficient could not be determined. Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.
FMI 12Vehicle speed sensor fault - Sensor signal implausible. Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.

Mercedes-Benz

FMI 3Vehicle Speed Sensor Circuit shorted to Ubat
FMI 4Vehicle Speed Sensor Circuit shorted to GND
FMI 5Vehicle Speed Sensor open Circuit (broken wire, terminal floating)
FMI 13Vehicle Speed Sensor Anti-Tamper Detection via ABS Vehicle Speed Comparison (ABS speed and Vehicle Speed Sensor are not consistent)
FMI 19Hall effect Vehicle Speed Sensor supply voltage out of range
FMI 20Vehicle Speed Sensor Drifted High Error (VSS signal not plausible)
FMI 21Vehicle Speed failure (VSS Signal Not Plausible)

Renault Trucks

FMI 6Short to battery positive. Repair: Check the wiring between the control unit and the clutch actuator (X1B/12, X1B/17). Run the diagnostic check of the clutch actuator. Switch the ignition off, switch it on again and repeat the test. If the fault persists, replace the control unit.
FMI 9CAN data bus link to VECU. Repair: Check the continuity of the CAN bus connected to the EBS unit (X1/1, X1/3). Check that the VECU is connected and works correctly.
FMI 10CAN data bus link to VECU. Repair: Check the continuity of the CAN bus connected to the EBS unit (X1/1, X1/3). Check that the VECU is connected and works correctly.
FMI 31CAN data bus link to VECU, fault not stored. Repair: Check the continuity of the CAN bus connected to the EBS unit (X1/1, X1/3). Check that the VECU is connected and works correctly.

SITRAK

FMI 3Vehicle speed sensor voltage above the upper limit. Scan tool code: P0503. Effect: Speed-based functions such as cruise control and the speed limiter do not work.
FMI 4Vehicle speed sensor voltage below the lower limit. Scan tool code: P0502. Effect: Speed-based functions such as cruise control and the speed limiter do not work.
FMI 8Vehicle speed signal from the tachograph or sensor not plausible. Scan tool code: P2162. Effect: Speed-based functions such as cruise control and the speed limiter do not work.
FMI 14Vehicle speed sensor not connected. Scan tool code: P2162. Effect: Speed-based functions such as cruise control and the speed limiter do not work.
FMI 15Vehicle speed above the maximum allowed. Scan tool code: P0279. Effect: Speed-based functions such as cruise control and the speed limiter do not work.
FMI 16Vehicle speed physical value above the upper limit. Scan tool code: P0500. Effect: Torque may be limited.
FMI 18Vehicle speed physical value below the lower limit. Scan tool code: P0500. Effect: Torque may be limited.

YaMZ

FMI 0Vehicle speed sensor fault (Maximum speed exceeded). Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.
FMI 2Vehicle speed sensor fault (Vehicle speed inconsistent with fuel delivery and crankshaft speed). Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.
FMI 11Vehicle speed sensor fault (Sensor coefficient could not be determined). Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.
FMI 12Vehicle speed sensor fault (Sensor signal implausible). Blink code: 3-2-4. Repair: Check the vehicle speed sensor and its wiring. Check the CAN bus connection.

ZF AS-Tronic

ZF AS-Tronic uses its own fault numbering: the number in the table below is an internal ZF code, not a J1939 SPN. It matches the title of this page by digit only and means something different.

FMI 6Short circuit to positive supply on valve Y16 output (clutch fast release).

What FMI means in J1939

SPN 84 FMI 084/0 · 84.0data above normal range (most severe level)
SPN 84 FMI 184/1 · 84.1data below normal range (most severe level)
SPN 84 FMI 284/2 · 84.2data erratic or intermittent
SPN 84 FMI 384/3 · 84.3voltage above normal or shorted high
SPN 84 FMI 484/4 · 84.4voltage below normal or shorted to ground
SPN 84 FMI 584/5 · 84.5current below normal or open circuit
SPN 84 FMI 684/6 · 84.6current above normal or grounded circuit
SPN 84 FMI 884/8 · 84.8abnormal frequency or pulse width
SPN 84 FMI 984/9 · 84.9abnormal update rate
SPN 84 FMI 1084/10 · 84.10abnormal rate of change
SPN 84 FMI 1184/11 · 84.11root cause not known
SPN 84 FMI 1284/12 · 84.12faulty device or component
SPN 84 FMI 1384/13 · 84.13calibration out of range
SPN 84 FMI 1484/14 · 84.14manufacturer-specific instructions
SPN 84 FMI 1584/15 · 84.15above normal — low severity
SPN 84 FMI 1684/16 · 84.16above normal — moderate severity
SPN 84 FMI 1884/18 · 84.18below normal — moderate severity
SPN 84 FMI 1984/19 · 84.19error in received network data
SPN 84 FMI 2084/20 · 84.20data drifted high
SPN 84 FMI 2184/21 · 84.21data drifted low
SPN 84 FMI 3184/31 · 84.31condition exists (see manufacturer description)

Can I keep driving

Do not drive. Stop as soon as it’s safe to do so — don’t keep going.

What happens if you keep driving

Time you have: To the nearest safe stop

The code is flagged critical: the manufacturer considers it unsafe to keep driving without checking.

This code alone cannot say what will fail next, so stop at the first safe opportunity and look at it on the spot.

That said, the manufacturer flags this code as critical — if in doubt, it is safer to stop and check on the spot.

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.