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Service bulletins for the 2021 Freightliner Cascadia

A bulletin is a manufacturer's communication to its dealers, as NHTSA indexes it. The summary is NHTSA's. The document is the manufacturer's: read it at NHTSA. A bulletin is not a recall, and listing a model year does not mean every vehicle of it is concerned.

509 on file from NHTSA, as of 2026-10-19.

By type

By component

Bulletins, newest first
SB54-3352020-09-16. Service bulletin. ELECTRICAL SYSTEM. Freightliner Service Bulletin for Optional 30K High-Current Trailer Cord Circuit Breaker Replacement. New Cascadia vehicles manufactured from September 1, 2016 through June 28, 2020 with an optional high current single- or dual-pole trailer cord were equipped with an auto-reset type I circuit breaker mounted in the battery cable access (BCA) box. Since type I circuit breakers can mask potential issues by resetting every time an over-current condition occurs, Daimler Trucks North America (DTNA) switched to a manual reset type III circuit breaker on June 29, 2020. This bulletin includes instructions for converting from a type I to a type III circuit breaker, how and where to reset a type III circuit breaker, and conditions to be aware of when troubleshooting a type III circuit breaker.
SB54-3312020-09-16. Service bulletin. VISIBILITY; EXTERIOR LIGHTING; ELECTRICAL SYSTEM. Updated Freightliner Service Bulletin for Updated ULB Control Unit for LED Headlamps. This bulletin replaces the version dated July 30, 2020. Information about a reman part has been added. New Cascadia vehicles with light emitting diode (LED) headlamps built from January 1, 2017 through February 17, 2020 may experience intermittent disabled headlamps due to an issue with the universal light ballast (ULB). The LED headlamps can turn off if the supply voltage drops below approximately 9V. This low voltage commonly and momentarily occurs when cranking the engine on a vehicle with batteries that are not fully charged. The momentary low voltage may cause the electronic ULB control unit to malfunction. The ULB may not resume normal function until the power supply to the headlamp is disconnected.
SB54-3292020-09-16. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. Updated Service Bulletin for Electrical Wall Chart and VPDM Cover on New Cascadia with Detroit Assurance 5.0 and Multi-Purpose Camera 2. This bulletin replaces the version dated 2/26/2020. Information about Service Bulletin 54-336 has been added.
20CSA-152020-09-02. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; EQUIPMENT. Customer Service Announcement for Release of DiagnosticLink 8.12 Service Pack 2. On Thursday, September 3, 2020, Service Pack (SP) 2 for DiagnosticLink 8.12 Standard and Professional will be made available to download from the Detroit Diesel server.
SS10347822020-09-01. Service bulletin. EQUIPMENT. Service Solution for New Cascadia Bluetooth Microphone Relocation. Similar to Service Solution 1034680 which also informs about relocating the microphone.
SS10347622020-09-01. Service bulletin. EQUIPMENT. Service Solution for P4 Cascadia Front HVAC Evaporator Freezing. Front evaporator freezes creating ice buildup, reducing airflow through the vents. The evaporator freezing condition is very hard or cannot be duplicated, in a repair facility. Because the condition is hard to duplicate, determining root cause is still under investigation.
CALFTL54-0112020-09-01. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Customer Advisory Letter for How to program the IPPC module using DiagnosticLink.
CALFTL54-010REV2020-09-01. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; SERVICE BRAKES, AIR:ANTILOCK:ABS WARNING LIGHT; EQUIPMENT. Revised Customer Advisory Letter for New Cascadia ABS Warning Light Illumination work instructions. Due to the enhanced vigilance of the New Cascadia ABS controller, some fault codes and indicator lights do not necessarily require immediate maintenance attention. DTNA and WABCO are currently jointly working on a long-term corrective plan for the condition. REVISED: This CAL replaces the CAL issued June 17th, 2020. The phrase "if equipped" in reference to cab load disconnect switches has been removed.
CALFTL-OILHUB2020-09-01. Service bulletin. STEERING; WHEELS. Customer Advisory Letter for Visual Inspection For Oil Presence In Hub. Visual Inspection is necessary for the condition of the oil level in the steer axle hubs.
ICI20-0262020-09-01. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Important Campaign Information Letter informing that revised bulletins for Detroit Diesel campaigns D20R1REV1 and D20M8REV1 have been posted on DTNAConnect.
D20R1REV12020-09-01. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM:SOFTWARE. Revised Detroit Emissions Recall for Daimler Trucks North America LLC, on behalf of its Detroit Powertrain Division, has determined that some Model Year 2020 GHG21 DD13 engines require reprogramming of the MCM to meet certification. NOTE: Reference 20TS-04 Detroit CPC501T GHG21 Only; Bootloader Update if New Cascadia CPC501T is not at the software level shown in this table. The Corrective Procedure also has been updated.
D20R12020-09-01. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. Detroit Emissions Recall for GHG21 Detroit DD13 Model Year 2020 Software Reprogramming. Daimler Trucks North America LLC, on behalf of its Detroit Powertrain Division, has determined that some Model Year 2020 GHG21 DD13 engines require reprogramming of the MCM to meet certification.
WI20-0152020-08-31. Service bulletin. LANE DEPARTURE. Warranty Information Letter for Active Lane Assist Steering Column - Providing Serial Number During Claim Entry. The serial number for an ALA steering column is scanned at installation and displays in OWL on the Major Components screen. Effective for repairs performed on or after August 24, 2020, if a factory-installed ALA steering column is replaced due to a warrantable failure, the serial number will be required on the Failure tab. If the replacement serial number is not entered on the claim, a red error message will display.
D20M8REV12020-08-29. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM:SOFTWARE. Revised Detroit Field Service Campaign for GHG17 & GHG21 Detroit DD13, DD15, and DD16 ACM Software Reprogramming. NOTE: Reference 20TS-04 – Detroit™ CPC501T GHG21 Only; Bootloader Update if New Cascadia CPC501T is not at the software level shown in this table.
ICI20-022R2020-08-29. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Revised letter is to announce a reimbursement available to dealers for travel to a customer's location to perform a recall or field service campaign. Potential travel reimbursement applies to DTNA truck dealers and Detroit Diesel distributors. Thomas Built Buses will be addressed separately.
SB26-0512020-08-29. Service bulletin. POWER TRAIN; EQUIPMENT. Updated Service Bulletin for DT12 Transmission Cooler Retrofit. This bulletin replaces the version dated 09/18/2019. The part number for the oil control valve has been updated in the parts table.
D20M82020-08-08. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. Detroit Field Service Campaign for GHG17 & GHG21 Detroit DD13, DD15, and DD16 ACM Software Reprogramming
FP31-0292020-08-08. Service bulletin. STRUCTURE:BODY:BUMPERS. Freightliner Parts technical bulletin for Aftermarket Bumper Replacement. In order to reduce part proliferation, and maintain relevant stock in the Parts Distribution Center (PDC), service bumpers were created. While ordering a production bumper replacement, order one of the eight service bumpers from Table 1, and relevant interchangeable parts from Table 2 based on vehicle configuration.
ICI20-0222020-08-05. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Important Campaign Information letter announcing Dealer Travel for Campaign Performance. This letter is to announce a reimbursement available to dealers for travel to a customerâ™s location to perform a recall or field service campaign.
WI20-0142020-08-05. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Warranty Information Letter for OWL and Warranty Manual Improvement: Sublets and Travel Time/Distance. In the spirit of continuous improvement, DTNA reviewed sublet-related policies and procedures. The goal was to improve language clarity and optimize processes.
WI20-0122020-08-03. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. Warranty Information Letter informing that to ensure that DTNA policies and service network practices align, the Warranty Department will be revising the Warranty Manual.
SB54-3322020-07-31. Service bulletin. ELECTRICAL SYSTEM. Freightliner Service Bulletin for In Rail Battery Box Cable Rub Repair. New Cascadia vehicles ordered with battery box data codes (282-014-BATTERY BOX[ES] MTD IN RL BOC or 29G-001-PLASTIC AUX BATT BOX MTD BTWN RLS) mounted on in rails at the back of the cab, have battery cables that are exposed to rubbing, which may result in excessive chaffing. Chaffing is observed more on the ground cable exiting the box. Typically, the battery rubs are found during the routine battery inspections. The symptoms related to excessive chafing could include low battery voltage faults, or slow or no engine crank.
SB54-3312020-07-31. Service bulletin. ELECTRICAL SYSTEM; EXTERIOR LIGHTING; VISIBILITY. Freightliner Service Bulletin for Updated ULB Control Unit for LED Headlamps. New Cascadia vehicles with light emitting diode (LED) headlamps built from January 1, 2017 through February 17, 2020 may experience intermittent disabled headlamps due to an issue with the universal light ballast (ULB). The LED headlamps can turn off if the supply voltage drops below approximately 9V. This low voltage commonly and momentarily occurs when cranking the engine on a vehicle with batteries that are not fully charged. The momentary low voltage may cause the electronic ULB control unit to malfunction. The ULB may not resume normal function until the power supply to the headlamp is disconnected.
20TS-052020-07-31. Service bulletin. ENGINE AND ENGINE COOLING. Technical Service Letter for EPA10, GHG14, GHG17 Diesel Particulate Filter (DPF) Compatibility. Note: This document supersedes 14 TS-25 and 15 TS-8. Detroit Diesel has determined that some, Diesel Particulate Filters (DPFs) are compatible in pairs and or can be mixed together within EPA10 and GHG14 Systems. For 1-BOX and Two-Box Configuration Aftertreatment Systems (ATS), this is only possible when the filters are used in accordance with Tables 1 and 2 shown below. All other DPFs, NOT mentioned below, are NOT compatible.
20OEM-052020-07-31. Service bulletin. ENGINE AND ENGINE COOLING. OEM and distributor announcement for DiagnosticLink 8.12 (Build 4527) was made available. All DTNA Service shops & OEM locations are required to maintain the latest version of software on each of their stations.

The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.