NHTSA safety investigation
NHTSA Investigation PE23010
Preliminary Evaluation · Daimler Trucks North America, LLC · FORWARD COLLISION AVOIDANCE: DYNAMIC BRAKE SUPPORT/BRAKE ASSIST
An investigation is not a finding that a defect exists.
NHTSA opens an investigation to examine whether a safety defect may exist. An open investigation is not a determination that a defect exists, and many investigations close without a recall. Investigations can, however, lead to one.
What NHTSA is examining
The agency's own description of the inquiry, quoted as published
Automatic Emergency Braking Errors
On May 26, 2023, the Office of Defects Investigation (ODI) opened a Preliminary Evaluation (PE23010) to assess reports of false positive activation of the Automatic Emergency Braking (AEB) system in model year (MY) 2017-2022 Daimler Trucks North America (DTNA) vehicles. The reports alleged that activation of the AEB system occurred while driving with no apparent obstruction in the vehicle's forward path, resulting in unexpected and sudden vehicle deceleration. ODI sent an information request letter to DTNA on June 15, 2023.In its September 1, 2023, response, DTNA indicated that it received of a total of 315 reports that may relate to the alleged defect in MY 2017-2022 DTNA vehicles. DTNA stated that the vast majority of false positive activation of the subject systems occur for very limited durations and result in a five mile per hour deceleration. ODI considered four AEB systems offered by DTNA: Detroit Assurance 2.0, Detroit Assurance 4.0, Detroit Assurance 5.0, and Wabco OnGuard. ODI’s analysis shows that of the Detroit Assurance versions, all fail at similar rates. The Wabco OnGuard AEB systems equipped on the same model and model year vehicles have experienced a significantly lower claim rate. To date, ODI has received a total of 32 consumer complaints of inadvertent activation of AEB in MY 2017-2022 DTNA vehicles. In total, ODI reviewed 347 unique (i.e., non-duplicative Vehicle Identification Number) reports that may relate to the alleged defect, which include 24 involving a crash, 13 reports involving an alleged injury and one report with a fatality. PE23010 has been upgraded to an Engineering Analysis (EA25006) to further assess the scope, frequency, and nature of the inadvertent AEB activations in MY 2017-2022 Freightliner Cascadia and Western Star 5700 vehicles.In particular, this EA will assess the safety consequences likely to arise in the scenarios during which the AEB inadvertently and unexpectedly activates, such as the speeds and conditions during which the activation occurs. To review the ODI reports cited in the Closing Resume ODI Report Identification Number document, go to NHTSA.gov.
An investigation is a separate record from a recall and from a manufacturer communication. A manufacturer campaign to repair a safety defect or a failure to meet a federal safety standard.
Investigation details
Identifiers, dates and outcome as recorded by NHTSA
- Action number
- PE23010
- Investigation type
- Preliminary Evaluation (PE)
- Status
- Closed
- Manufacturer
- Daimler Trucks North America, LLC
- Component
- FORWARD COLLISION AVOIDANCE: DYNAMIC BRAKE SUPPORT/BRAKE ASSIST
- Opened
- May 26, 2023
- Closed
- Oct 23, 2025
- Associated recall campaign
- None recorded
Vehicles named in this investigation
12 model years across 2 models
Being named here means NHTSA included the vehicle in the scope of its inquiry. It is not a statement that these vehicles have a defect.