What It Means
A timing malfunction means the ELD cannot maintain the UTC time accuracy required by the technical specifications in 49 CFR 395 Appendix A. ELDs are required to synchronize their internal clocks with UTC using a reliable time source — typically GPS satellite time or another network time source — and maintain accuracy within defined limits. When the device detects that it cannot meet this requirement, it flags a timing malfunction.
The accuracy requirement exists because HOS records are time-stamped, and records with inaccurate timestamps could misrepresent when duty status changes occurred. A clock that is wrong by more than the allowed tolerance creates compliance uncertainty.
What To Record
Record the malfunction indicator text, time of occurrence (as best as the device can report), vehicle, and driver. Note whether GPS positioning is also unavailable — a GPS signal loss can affect both timing and positioning simultaneously if the device depends on GPS for both. If the device has been in a location with poor satellite reception for an extended period, document that context.
What Drivers Should Do
Follow your motor carrier's malfunction procedure and notify the carrier within 24 hours. The 8-day repair or replace rule applies. For the duration of the malfunction, maintain supporting documentation as required. Some devices will continue recording with a degraded time source and automatically correct when satellite sync is restored — consult your ELD provider's documentation for device-specific behavior.
Do not manually adjust the ELD clock unless the device's approved interface requires it — manual time entry may be a separate compliance obligation depending on the device.
What Not To Do
Do not assume a timing malfunction will resolve itself once the truck is back outdoors and GPS signals are available. Some timing faults indicate an internal hardware issue with the time-keeping circuit that will not recover from GPS sync alone. Verify with the ELD provider whether the device requires replacement.
Related Pages
Related Fault Code Pages
Sources
- ELD Malfunctions and Data Diagnostic Events Federal Motor Carrier Safety Administration · government · accessed 2026-05-05 · confidence high
Source: Federal Motor Carrier Safety Administration, ELD Malfunctions and Data Diagnostic Events. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - 49 CFR 395.34 - ELD malfunctions and data diagnostic events Electronic Code of Federal Regulations · government · accessed 2026-05-05 · confidence high
Source: Electronic Code of Federal Regulations, 49 CFR 395.34 - ELD malfunctions and data diagnostic events. This page paraphrases factual fields only and is not a substitute for the original document.
Open source - 49 CFR Part 395 Appendix A to Subpart B - Functional Specifications for ELDs Electronic Code of Federal Regulations · government · accessed 2026-05-05 · confidence high
Source: Electronic Code of Federal Regulations, 49 CFR Part 395 Appendix A to Subpart B - Functional Specifications for ELDs. This page paraphrases factual fields only and is not a substitute for the original document.
Open source
FAQ
Can operating in a tunnel or underground garage cause a timing malfunction?
Brief GPS signal loss in a tunnel or parking structure typically does not trigger a timing malfunction because most ELD devices use an internal clock that maintains accuracy for short periods without a GPS fix. A timing malfunction is more likely to appear when the device has been unable to synchronize for an extended duration, or when the internal time-keeping circuit itself has a fault.
What is the acceptable time accuracy requirement for ELDs?
The technical specifications in 49 CFR 395 Appendix A specify that the ELD must synchronize with a UTC-based time source. The specific accuracy requirement and synchronization frequency are detailed in the technical specification. Consult the current version of Appendix A to Part 395 for the precise tolerance, as specifications can be updated.
Does a timing malfunction affect older records that are already stored on the device?
Records already stored before the malfunction was detected are not retroactively changed. The malfunction indicator covers the period during which time accuracy may be affected. Records from before the malfunction event retain their original timestamps.