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 sudden vehicle deceleration. 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 in 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 are failing at similar rates. The 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 Numbers) reports that may relate to the alleged defect, which include 24 reports involving a crash, 13 reports involving an alleged injury and one report with a fatality. PE23010 has been upgraded to an Engineering Analysis to further assess the scope, frequency, and potential safety related consequences of the inadvertent AEB activations in MY 2017-2022 DTNA vehicles. To review the ODI reports cited in the Opening Resume ODI Report Identification Number document, go to NHTSA.gov.
FORWARD COLLISION AVOIDANCE: DYNAMIC BRAKE SUPPORT/BRAKE ASSIST
PE23010ClosedPreliminary Evaluation Automatic Emergency Braking Errors
Opened May 26, 2023
Closed Oct 23, 2025
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.
FORWARD COLLISION AVOIDANCE: DYNAMIC BRAKE SUPPORT/BRAKE ASSIST
PE21004ClosedPreliminary Evaluation Engine Electrical Wiring Harness Chafe
Opened Feb 25, 2021
Closed Jan 14, 2025
The Office of Defects Investigation (ODI) opened this Preliminary Evaluation to investigate reports of engine electrical wiring harness chafe on the subject vehicles.ODI analysis found thousands of unique harness part numbers, spanning the two generations of vehicle chassis assembled at multiple vehicle assembly plants in two different countries, with multiple sub-models, incorporating over thirty powertrain choices.Each wiring harness could contain several dozen individual wires for power, ground and communication purposes depending on the multitude of equipment options available for custom vehicle configuration. ODI identified three primary areas where a wiring harness bundle may chafe: the air compressor support bracket, the transmission case, or the coolant surge tank. In each case, the root cause was some combination of inadequate design clearance, installation variability and relative motion between the wiring harness and the point of contact, such as from vibration. The chafing could result in a range of consequences from none to various diagnostic fault codes, telltale illumination, driver warning center messages, erratic electrical component operation, difficult or no engine start condition, engine de-rate (power reduction), engine shut down, inoperative transmission gear selection, or an unexpected shift to neutral.These potential consequences vary depending on the specific damaged wire in the harness and the exact failure mode, such as intermittent short circuit to ground or open circuit. Generally, the chafing resulted in a progressive series of driver warnings with high levels of detectability over the course of several days and ignition cycles. Drivers usually heed warnings before an engine shutdown condition occurs and the driver may override an engine shutdown countdown timer using the override switch. If the driver allows the shutdown event to occur, the engine can almost always be immediately restarted. Incident rates for an engine shutdown with no warning or a transmission shift to neutral while driving are both very low. ODI received one complaint (NHTSA ID Number 11366557) from a fleet mechanic, who reported in a subsequent interview that he repaired at least six subject vehicles that experienced the alleged defect condition. However, there have been no new Vehicle Owner Questionnaire complaints received by ODI since opening this investigation, and there are no known crashes, fires or thermal events, or injuries or deaths related to the alleged defect. Accordingly, no safety-related defect trend has been identified. Based on available information, this investigation is closed.The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist. The Agency reserves the right to take additional action if warranted by future circumstances. To review the ODI report cited in the Closing Resume ODI Report Identification Numbers document, go to NHTSA.gov.
ELECTRICAL SYSTEM
PE21006ClosedPreliminary Evaluation Halogen Headlights May Cause Fires
Opened Feb 25, 2021
Closed Jul 16, 2021
In its process for evaluating Early Warning Reporting data, the Office of Defects Investigation (ODI) found twenty-four (24) field reports involving headlight fires on Freightliner Cascadia trucks, model years 2017 and newer produced by the vehicle manufacturer, Daimler Trucks North America (DTNA). ODI contacted DTNA and learned that it was aware of halogen bulb-related thermal events. DTNA stated a belief that the issue was due to incorrect bulb replacement during maintenance. However, some vehicles experienced fires within the original equipment halogen bulb's expected life range.In July 2019, DTNA released a service bulletin and a training video covering proper headlight bulb replacement. There have been 17 fires, with 3 total vehicle losses, since DTNA released this extra training information.On February 25, 2021, ODI opened a Preliminary Evaluation (PE21-006) and sent an Information Request (IR) letter to DTNA.After the PE opening, DTNA reevaluated the data and found additional thermal events at low mileages and decided to file a recall. On May 14, 2021, DTNA submitted recall 21V-357 for 72,508 vehicles covering 2017-2022 models (exceeding the population and model years of this investigation). The planned owner and dealer notification date is July 12, 2021.For the remedy, DTNA will open up the 2-inch access into a 4-inch access hole into the inner fender to provide better access for the maintenance replacement of the bulb, and add a label that provides a visible warning to aid in the correct installation during the change. Additionally, a new foam grommet will replace the flammable rubber boots for both the high and low beam bulbs, improving access to the interface point where the bulbs install into the socket of the reflector. ODI believes that the scope of DTNA recall 21V-357 is sufficient, and accordingly, PE21-006 is closed. The closing of this investigation does not constitute a finding by NHTSA that a safety-related defect does not exist on other models or MY vehicles outside of the recall scope. The agency reserves the right to take further action if warranted by the circumstances.
EXTERIOR LIGHTING:HEADLIGHTSLed to recall 21V357000