FMCSA and eCFR-backed guide to ELD malfunctions and data diagnostic event categories.
ELD malfunction categories are compliance-oriented. They describe whether an electronic logging device can capture, retain, synchronize, and transfer required records. Browse the ELD topic pages for individual malfunction and data diagnostic event categories.
FMCSA distinguishes malfunctions from data diagnostic events. Diagnostic events often point to missing or inconsistent data, while malfunctions indicate a more serious or persistent failure condition. See the source registry for the FMCSA and eCFR documents used.
Common categories include power, engine synchronization, missing required data elements, timing, positioning, data recording, data transfer, and unidentified driving records. Use the fault code lookup to search verified ELD records by keyword.
Electronic Logging Device · Power compliance monitoring
FMCSA-sourced explanation of ELD power malfunction: what triggers it, what it means for HOS records, and required driver and carrier steps under 49 CFR 395.34.
Electronic Logging Device · Engine ECM data connection
FMCSA-sourced explanation of ELD engine synchronization malfunctions: what ECM data the ELD requires, what causes the connection to fail, and required regulatory steps under 49 CFR 395.
Electronic Logging Device · Time synchronization
FMCSA-sourced explanation of ELD timing compliance malfunctions: UTC synchronization requirements, what causes timing faults, and how they affect HOS record accuracy under 49 CFR 395 Appendix A.
Electronic Logging Device · Position measurement
FMCSA-sourced explanation of ELD positioning malfunctions: GPS and location requirements, what causes positioning failures, and compliance steps under 49 CFR 395 Appendix A.
Electronic Logging Device · Record storage and retrieval
FMCSA-sourced explanation of ELD data recording malfunctions: what the device must record and retain, what causes this failure, and required steps under 49 CFR 395.34 including record reconstruction.
Electronic Logging Device · Roadside data transfer
FMCSA-sourced explanation of ELD data transfer malfunctions: required transfer methods, what causes transfer failures, and how to respond at roadside and when planning for repair under 49 CFR 395.
Electronic Logging Device · Required log data fields
FMCSA-sourced explanation of the ELD missing required data elements diagnostic event: which fields are required, what causes them to be absent at record creation, and how to respond.
Electronic Logging Device · Unidentified driver profile
FMCSA-sourced explanation of the ELD unidentified driving records data diagnostic event: what triggers the diagnostic indicator, the 24-hour threshold, how to assign records, and compliance obligations under 49 CFR 395.
A data diagnostic event indicates a data inconsistency that may be resolvable. A malfunction indicates a more serious or persistent ELD compliance problem under FMCSA rules.
Power, engine synchronization, missing data, timing, positioning, data recording, data transfer, and unidentified driving records.
No. They are educational summaries. Verify current FMCSA and eCFR requirements and follow carrier procedures.
