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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

Only bulletins with component: Electrical system are shown. Show all

Bulletins, newest first
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.
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.
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.
D20M82020-08-08. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. Detroit Field Service Campaign for GHG17 & GHG21 Detroit DD13, DD15, and DD16 ACM Software Reprogramming
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.
SB54-3332020-07-30. Service bulletin. EXTERIOR LIGHTING; ELECTRICAL SYSTEM. Service Bulletin for Installing a Fog Lamp Backshell. The connector that attaches to the fog lamp is exposed to water spray from the front tires. Even though the connector is sealed, water spray, in addition to wiring that may be pulled sideways, can cause water intrusion into the connector. A backshell can be added to the connector to provide shielding from direct water spray. It also provides strain relief for the wires entering the connector.
SS10347402020-06-26. Service bulletin. ELECTRICAL SYSTEM. Service Solution for CTP Reset Warning When Using DiagnosticLink Version 8.12. Starting with DiagnosticLink version 8.12, a new Common Telematics Platform (cTP) Not Communicating Over the Air symptom based Advanced Diagnostic procedure was released with the intent to resolve specific issues on a certain population of trucks. Please, do not run this procedure unless specifically directed by a DTNA field service representative, or by the Detroit Connect support team.
SS10346842020-04-09. Service bulletin. EXTERIOR LIGHTING; ELECTRICAL SYSTEM. Service Solution for P4 New Cascadia Road Lamp Strain Relief and Water Protection For Electrical Connection. The connector that attaches to the road lamp is exposed to water spray from the vehicles front tires. Even though the connector is sealed, water spray, in conjunction with wiring that may be pulled sideways, can attribute to water intrusion into the connector.
SS10346702020-03-19. Service bulletin. ELECTRICAL SYSTEM. Service Solution for fault code VRDU 524127/9 - lost communication with the MPC. VRDU fault code 524127/9 is often caused by lack of ignition supply to the MPC, which causes it to stop communicating.
20CSA-032020-03-06. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE. Customer Service Announcement saying that Service Pack (SP) 2 for Diagnostic Link 8.11 Standard and Professional will be available for download from the Detroit Diesel server.
P4HalogenEnhance2020-03-04. Service bulletin. ELECTRICAL SYSTEM; EXTERIOR LIGHTING. Customer Maintenance Enhancements for the P4 Halogen Lamp replacement procedure.
DRVRFacingCamera2020-03-03. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. DASH letter to dealers on updating the driver facing camera to improve captured video quality. The concern only impacts the quality of video captured and transmitted to the SafetyDirect Portal during an Active Brake Assist event or driver requested video recording.
SB54-3292020-03-03. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. Service Bulletin for Electrical Wall Chart and VPDM Cover on New Cascadia with Detroit Assurance 5.0 and Multi-Purpose Camera 2.
CALHIGHCURRENT2020-03-03. Service bulletin. ELECTRICAL SYSTEM:WIRING:FUSES AND CIRCUIT BREAKERS. Customer Advisory Letter that an inspection to determine if the high current breaker has been bypassed.

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