SPN 1808 — Yaw Rate
Drive with cautionEnough to reach the yard
Updated: 2026-11-14
J1939 code SPN 1808. Below — how the fault is worded at the factory by Bendix ABS/ESP, KAMAZ EBS3 and Meritor (ex-WABCO), and what the second half of the code (FMI) means in the standard.
How to check it yourself
The yaw rate sensor in the stability control unit. It shows how fast the vehicle rotates about its vertical axis. From it the unit decides whether it is time to intervene in a turn.
What it should read
| Signal on a stationary vehicle | per the manufacturer's manual |
| Signal in a turn | changes — per diagnostics |
Check order
- Check the stability control unit's connector, its mounting and the supply of the sensor bus.
- FMI 2, 9, 13, 14 (Bendix: sensor CAN bus supply, voltage out of range): check the unit's power and the bus.
- FMI 1, 2, 3, 5 (Meritor: signal does not change under load): sensor — calibration per the manual after frame repair or replacing the unit.
Common causes — from most to least frequent
- Stability control sensor or unit.
- Supply of the sensor bus.
- Calibration after repair.
Bendix ABS/ESPKAMAZ EBS3Meritor (ex-WABCO)
Bendix ABS/ESP
| FMI 2 | Sensor CAN Supply Voltage Error; ESP Sensor Voltage Out of Range; YRS Signal Out of Range; YRS Sensor Reversed Signal; YRS Invalid Signal; YRS Gradient Error; YRS Static BITE Error; YRS Dynamic BITE Error; YRS Fast Calibration Error; YRS Static Calibration Error; YRS Normal Calibration Error; YRS Sensitivity Calibration Error; YRS Plausibility Check (Ref Yaw Rate); YRS Plausibility Error (Inside ECU-Specific Limits); YRS Plausibility Error (Outside ECU-Specific Limits); Yaw Rate Sensor Vibration Detected |
| FMI 9 | YRS CAN Timeout |
| FMI 13 | YRS Sign Check Not Finished |
| FMI 14 | Erratic ESP Sensor Signal |
EBS3 brakes (WABCO)
| FMI 0 | Yaw rate: data valid but above normal range (most severe level) |
| FMI 1 | Yaw rate: data valid but below normal range (most severe level) |
| FMI 2 | Yaw rate: data erratic, intermittent or incorrect |
| FMI 7 | Yaw rate: mechanical system not responding or out of adjustment |
| FMI 11 | Yaw rate: failure mode not identifiable, root cause unknown |
| FMI 12 | Yaw rate: bad intelligent device or component |
| FMI 13 | Yaw rate: out of calibration |
| FMI 14 | Yaw rate: special instructions required |
| FMI 15 | Yaw rate: data valid but above normal range (least severe level) |
| FMI 16 | Yaw rate: data valid but above normal range (moderately severe level) |
| FMI 17 | Yaw rate: data valid but below normal range (least severe level) |
| FMI 19 | Yaw rate: network data received in error |
Meritor (ex-WABCO)
| FMI 1 | Minimum Dynamic Failure/Yaw Rate |
| FMI 2 | Range Check Failure of Yaw Rate Sensor Signal |
| FMI 3 | Drift Failure of Yaw Rate Sensor Signal (Standstill) |
| FMI 5 | Offset Failure of Yaw Rate Sensor Signal |
| FMI 12 | ESC Module Failure Flag 'Yaw Rate Sensor' |
| FMI 14 | Yaw Rate Cross Check (Yaw Rate Signal) |
| FMI 17 | Neutral Value Detection (Yaw Rate) |
What FMI means in J1939
Can I keep driving
Drive with caution. The ABS on this wheel or axle may be off, but the service brakes work. On a slippery road brake gently. Get it repaired soon.
What happens if you keep driving
The ABS on this wheel or axle may be out of action, while the service brakes still work. On a dry road you may notice no difference.
On a slippery road brake gently and keep a longer following distance. Do not put the repair off: if the red brake lamp comes on or the pedal feels soft, stop.
Nearby: other
- SPN 1194Anti-Theft System Encryption Key Present Indicator
- SPN 1213Malfunction Indicator Lamp (MIL)
- SPN 1272Ignition Coil #5
- SPN 1324Misfire, Cylinder #2
- SPN 1408Ignition Coil Secondary Winding Output, Cylinder #16
- SPN 1809Lateral Acceleration
- SPN 3413Door 1 Open Status
- SPN 3841Auxiliary Input/Output #18
- SPN 3871Auxiliary Input/Output #48
- SPN 3873Auxiliary Input/Output #50
Related codes
- SPN 1188Turbocharger 1 Wastegate Actuator
- SPN 1081"Wait to Start" Lamp
- SPN 1068Brake Signal Sensor #2
- SPN 1065Lining Wear Sensor, Axle 3, Right
- SPN 1062Lining Wear Sensor, Axle 2, Left
- SPN 1057Backup Pneumatic Pressure Control, Trailer Control
- SPN 1056Electronic Pressure Control, Trailer Control
- SPN 1048Backup Pneumatic Pressure Control, Axle 1
Makes with this code
Bendix ABS/ESPKAMAZ EBS3Meritor (ex-WABCO)
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