NHTSA Office of Defects Investigation
Preliminary Evaluation PE21-004: Engine Electrical Wiring Harness Chafe
- Closed
NHTSA's Office of Defects Investigation opened Preliminary Evaluation PE21-004 on February 25, 2021 and closed it on January 14, 2025. NHTSA's investigations file lists the 2017–2021 Freightliner Cascadia for it.
Updated daily from NHTSA's investigations file
Key facts
- NHTSA number
- PE21-004 (also written PE21004)
- Investigation type
- Preliminary Evaluation The first stage of most defect investigations: NHTSA's Office of Defects Investigation gathers basic information about a possible safety defect, including from the manufacturer.
- Status
- Closed January 14, 2025
- Opened
- Closed
- Vehicle or equipment manufacturer
- Daimler Trucks North America, LLC
- Components
- Electrical System; Electrical System — Instrument Cluster/Panel; Electrical System — Wiring; Electrical System — Wiring — Front Underhood; Engine; Engine and Engine Cooling; Engine and Engine Cooling — Engine; Engine and Engine Cooling — Engine — Diesel; Engine and Engine Cooling — Engine — Engine Control Module (ECU/ECM)
- Vehicles and equipment
- 2017–2021 Freightliner Cascadia
A recall appears here only when NHTSA's investigations file links one to the investigation; NHTSA's summary or record can name others.
NHTSA's summary
As NHTSA's Office of Defects Investigation wrote it for Preliminary Evaluation PE21-004.
try.vin does not copy NHTSA's investigation documents; NHTSA's investigation record lists the ones NHTSA has published.
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.
Vehicles and equipment listed for this investigation
NHTSA's investigations file lists these vehicles and equipment for Preliminary Evaluation PE21-004. A listed model year means only that an investigation names it; it says nothing about any particular vehicle. Model years with a try.vin recall page link to that page's NHTSA investigations section.
What an NHTSA investigation is
NHTSA's Office of Defects Investigation (ODI) looks into possible safety defects in vehicles and equipment, often after owner complaints. An investigation usually starts as a Preliminary Evaluation, or as a Recall Query when it concerns whether an existing recall covers the right vehicles or fixes the problem, and ODI can upgrade it to a more detailed Engineering Analysis. A Defect Petition asks NHTSA to open an investigation, and Audit and Equipment Queries are administrative investigations into whether companies complied with federal vehicle safety requirements, such as reporting, recall and certification rules.
An open investigation is not a finding that a safety defect exists, and NHTSA can close one without a recall.
To see whether a specific vehicle has an open recall, enter its VIN at nhtsa.gov/recalls.
Free VIN check: decode a VIN to see its year, make and model.
Sources
NHTSA's investigation record for PE21-004
Investigation details come from NHTSA's investigations file, which try.vin imports once a day. The investigation types are described from the U.S. Department of Transportation Inspector General's May 2023 report on NHTSA's Office of Defects Investigation, NHTSA's petition rules (49 CFR Parts 552 and 557) and NHTSA's Office of Defects Investigation procedures. How try.vin reads NHTSA investigations.