Spn 5681 Fmi 9 is a specific fault code related to the Wabco OnGuard Advanced Emergency Braking System (AEBS). This code indicates a communication issue between the AEBS and the vehicle’s display or instrument cluster. This article will delve into the meaning of SPN 5681 FMI 9, its potential causes, and troubleshooting steps.
Decoding SPN 5681 FMI 9
SPN 5681 FMI 9 stands for:
- SPN: Suspect Parameter Number (5681)
- FMI: Failure Mode Indicator (9) – Abnormal Update Rate
This specific combination signifies that the J1939 message from the AEBS2 system is not being received by the display, or the message is intermittent. Essentially, the display isn’t getting the information it needs from the braking system. This can lead to a lack of critical warnings or information for the driver.
Troubleshooting SPN 5681 FMI 9
The Wabco OnGuard manual provides the following troubleshooting steps for SPN 5681 FMI 9:
- Check Power and Network Connections: The first step is to verify the power and J1939 network connection to the display or instrument cluster. Look for loose connections, damaged wiring, or blown fuses. Intermittent issues could point to a loose connection.
- Verify Harness: Ensure that the correct harness is being used and that it is properly connected. Consult the wiring diagrams for your specific vehicle and system.
- Software Version: Confirm that the display or instrument cluster has the correct software version installed. Outdated software can sometimes cause communication issues. Updates may be available through the manufacturer.
Important Considerations for Wabco Systems
When working with Wabco systems, keep these points in mind:
- Active Fault Codes: Only currently active fault codes will be displayed.
- TOOLBOX Software: Wabco fault codes can often only be viewed using the specialized TOOLBOX software.
- System Disable: Active fault codes can sometimes cause partial or full system disablement, depending on the affected functions (ACC or CMS).
- Clear Other Codes First: Before addressing SPN 5681 FMI 9, clear any other fault codes from other vehicle modules. This helps isolate the problem.
- Clearing CMS Codes: A specific procedure is required to clear CMS codes: Cycle the ignition OFF for at least two minutes, then ON. Start the engine and let it idle for at least two minutes.
Bendix Systems and SPN 5681 FMI 9
While Bendix also utilizes the SPN/FMI system, they employ a different coding structure and don’t have a direct equivalent to SPN 5681. Bendix systems often use blink codes for diagnostics, requiring a different approach for troubleshooting.
Conclusion
SPN 5681 FMI 9 indicates a communication problem within the Wabco OnGuard AEBS. By systematically checking power, connections, harness integrity, and software versions, technicians can effectively diagnose and resolve the issue. Remember to consult the official Wabco OnGuard documentation for the most accurate and up-to-date information specific to your vehicle and system. Addressing this code promptly is crucial for ensuring the proper function of the advanced emergency braking system and maintaining overall vehicle safety.
