Firmware version 5.16.16 includes improvements to how the speed filter is synchronized with other system components. On vehicles with poor or unstable CAN signal quality, this change may produce unexpected results, specifically, an increase in Harsh Acceleration (HA) and Harsh Braking (HB) events on your telematics reports.
Vehicles with frequent CAN signal dropouts, unstable wiring, or wireless CAN setups are most at risk. Vehicles running older CAN scripts are at higher risk.
Who may be affected
Vehicles most likely to experience issues are those with:
- Frequent CAN signal dropouts
- Unstable wiring
- Wireless CAN setups
- Older or multi-source CAN scripts
What you may observe
On affected installations, you may notice an increase in harsh events being recorded. This can have a knock-on effect on driver scoring, benchmarks, and monitored event data. If you are not seeing any unexpected changes, no action is required.
Contributing factors
Two separate factors have been identified that may contribute to this increase.
Issue – Incorrect speed reading during CAN signal loss
When a vehicle's CAN bus signal drops out, certain device scripts are incorrectly reporting a speed of zero rather than recognizing the absence of data. The device interprets this as an actual speed change, triggering false HA/HB events. This will be resolved in the upcoming firmware release (5.16.X).
Issue 2 – Driver scoring correction for multi-source CAN configurations
A long-standing issue in earlier firmware versions meant that devices running multi-source CAN scripts were not accurately detecting and scoring driver behavior events. Firmware 5.16.16 includes a correction to this logic. Clients using multi-source CAN configurations may notice an increase in HA/HB events as a result. Tis reflects more accurate scoring rather than a deterioration in driver behavior.
Recommended mitigation
If you are observing the effects described above, two options are available:
- Upgrade to a newer CAN script. Check with your configuration team before doing so, as newer scripts may require changes to associated configuration parameters.
- Have a technician inspect the CAN installation to identify and resolve the underlying cause of signal dropouts. This is especially recommended for wireless CAN setups.
Please reach out to our support team if you would like help identifying whether your vehicles may be affected.