Code Details
| Display code | WABCO RSSplus SID 5 FMI 13 |
|---|---|
| SPN | Not applicable or not verified |
| FMI | 13 |
| OEM code | WABCO / ZF SID 5 FMI 13 |
| Manufacturer | WABCO / ZF |
| System | Trailer ABS / RSSplus |
| Component | Wheel Sensor e |
| Source address | Unknown or not applicable |
| Severity | high |
| Review status | ai source checked |
| Source confidence | high |
| Last reviewed | 2026-04-09 |
Plain-English Meaning
FMI 13 flags a configuration or calibration mismatch rather than a wiring fault or a mechanical issue. The sensor at position E is producing a signal, but one or more of its characteristics — output type, frequency calibration, or operational parameters — do not match what the RSSplus ECU is configured to expect. This type of code often appears after wheel-end service with parts that do not match the original specification, or after changes to the ECU configuration.
WABCO MM-0888 FMI 13 is listed as 'sensor signal characteristic or configuration concern' for Wheel Sensor e. In J1939 and SPN/FMI systems generally, FMI 13 is used for calibration and configuration mismatch conditions. In the RSSplus context, this can indicate that the sensor's output characteristics (active vs. passive, output voltage levels, frequency-to-speed ratio) do not match the ECU's programmed configuration for that sensor position.
Common Symptoms
- Trailer ABS lamp on after wheel-end service, sensor replacement, or ECU replacement or reprogramming
- Code may be persistent from initial installation rather than developing after a period of normal operation
- Sensor E may produce a signal in WABCO PC diagnostics but with characteristics that differ from expected
Possible Causes
Possible causes may include the items below. The list is not a parts diagnosis.
- Wrong sensor type installed — active sensor installed where passive is configured (or vice versa)
- Sensor with different output voltage levels or frequency-to-speed ratio than the ECU's calibration
- ECU replaced with a unit configured for a different sensor specification than what is installed
- WABCO PC diagnostic tool configuration change that no longer matches the installed hardware
First Checks
- Confirm the sensor type installed at position E matches the WABCO specification for this trailer's RSSplus system — passive or active, and the specific output specification.
- If a sensor replacement was recently performed, verify the replacement part number against the original and the WABCO compatibility list.
- If an ECU was recently replaced or reconfigured, confirm the configuration matches the installed sensor and tone ring specifications using WABCO PC diagnostics.
- Contact the WABCO/ZF service network or an authorized trailer brake system technician if the configuration does not match available parts and reconfiguration is needed.
Can I Keep Driving?
Trailer ABS and brake-related codes should be handled conservatively. Stop safely for brake warnings, red stop lamps, abnormal braking, wheel-end concerns, or any severe warning condition, and follow fleet or OEM guidance.
Related Lookup Pages
Sources
- WABCO RSSplus Trailer ABS Maintenance Manual MM-0888 WABCO / ZF Commercial Vehicle Solutions · oem · accessed 2026-05-05 · confidence high
Source: WABCO / ZF Commercial Vehicle Solutions, WABCO RSSplus Trailer ABS Maintenance Manual MM-0888. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - TOOLBOX PLUS Diagnostic Software ZF Commercial Vehicle Solutions · oem · accessed 2026-05-05 · confidence medium
Source: ZF Commercial Vehicle Solutions, TOOLBOX PLUS Diagnostic Software. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
Can I use any active wheel speed sensor on a WABCO RSSplus trailer?
No. Sensor compatibility in WABCO RSSplus systems depends on the sensor's output type, voltage characteristics, and the ECU's configuration. Using a sensor with different output specifications than what the ECU is calibrated for can trigger FMI 13. Use WABCO-approved replacement sensors or parts confirmed compatible by WABCO service documentation.
Can the ECU be reconfigured to accept a different sensor type?
In many cases, the WABCO PC diagnostic tool can reconfigure the ECU for a different sensor specification. However, this should only be done by a qualified technician following WABCO service procedures, as an incorrect configuration could affect ABS performance. Do not attempt ECU reconfiguration without access to WABCO service data.
Does FMI 13 on a wheel sensor indicate a safety risk?
A configuration mismatch means the ABS system may not be processing the wheel speed signal correctly for the affected wheel position. ABS function on that channel may be unreliable. The system should be corrected before relying on full ABS functionality on the trailer.