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Service bulletins for the 2020 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.

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

By type

By component

Only bulletins with component: Engine are shown. Show all

Bulletins, newest first
TechTalk357822021-06-02. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. Tech Talk discussion on J1939 datalink failure codes.
FAB1532021-05-18. Service bulletin. ENGINE AND ENGINE COOLING; ELECTRICAL SYSTEM; FUEL SYSTEM, GASOLINE. Freightliner Action Bulletin FAB153 New Harness Highway for Cascadia
TechTalk80602021-05-06. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT; ENGINE AND ENGINE COOLING. Tech Talk continuing discussion on CGW lost communication with cpc.
WI21-0092021-04-24. Service bulletin. ENGINE AND ENGINE COOLING. Warranty Information letter announcing that DTNA is increasing the Standard Diagnostic Times (SDTs) shown. The updated after treatment system (ATS) diesel exhaust fluid (DEF) pump times will be applied to repair orders opened on or after April 12, 2021.
TechTalk81342021-04-06. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; ENGINE AND ENGINE COOLING. Tech Talk continuing discussion on SCR conversion codes only when bobtailing.
SF6192021-03-31. Service bulletin. ENGINE AND ENGINE COOLING. Field Service Campaign for Cascadia Cummins Natural Gas Engine Exhaust Shield. On certain vehicles, there may be early heat degradation at the front right cab mount due to excessive heat exposure. An exhaust shield will be installed on all vehicles involved.
SB49-0382021-03-24. Service bulletin. ENGINE AND ENGINE COOLING. Revised Freightliner Service Bulletin for netized Fill Neck for Six-Gallon DEF Tanks. A design change removed the magnets from the fill necks for some 6-gallon diesel exhaust fluid (DEF) tanks. If the vehicle is equipped with a non-magnetic fill neck 04-32529-000, it can be updated to a magnetic neck 04-32529-001. This bulletin replaces the version dated 04/18/2017. Updated availability of magnetic fill neck option for other diesel exhaust fluid (DEF) tank part numbers.
TechTalk81262021-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on D20M8 having updates greater than Recall requires in server.
TechTalk81342021-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on scr conversion codes only when bobtailing.
TechTalk67412021-03-02. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on P4 cascadia codes 3597 4 & 5741 13 only active with key off
WI21-0042021-03-02. Service bulletin. POWER TRAIN; ENGINE AND ENGINE COOLING. Warranty Information Letter for Detroit Resources: Exploded View DD Platform and DT12 Posters. Detroit's TechComm team created visual aids for the network and released exploded view posters for DD platform engines. In early 2021, Detroit added multiple DT12 posters.
21TS-042021-03-02. Service bulletin. ENGINE AND ENGINE COOLING. Technical Service Letter for Gen 5 DD15 Instrument Panel Oil Pressure Gauge Operation. Gen 5 DD15 equipped units have been brought in for service with a complaint of the instrument panel oil pressure gauge not moving during unit operation and/or stuck at 50PSI. The instrument panel oil pressure gauge does not operate the same as with previous engine models. Please be advised, this is normal operation and no further diagnostics are required. Do not down a unit for this complaint.
21OEM-062021-03-01. Service bulletin. ENGINE AND ENGINE COOLING. Starting on November 23, 2020, DiagnosticLink 8.13 (Build 4527) was made available. Current subscribers of DiagnosticLink 8.11 or 8.12 may upgrade to DiagnosticLink 8.13 at no cost. All DTNA Service shops & OEM locations are required to maintain the latest version of software on each of their stations.
20TS-07REV2021-03-01. Service bulletin. ENGINE AND ENGINE COOLING. Revised Technical Service Letter for Cold Weather Faults on GHG17/21 DD13 with MCM Software Version 14. Due to colder weather, there may be an increase in the frequency of faults, noted below, on GHG17/21 DD13 trucks built after June 5th 2019. This is due to a calibration issue in the current MCM software (14.1.1.5 or 14.2.1.3). New software is scheduled for release in the first quarter of 2021 that will address these faults.
SB54-3082021-02-26. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE; EQUIPMENT. Freightliner Service Bulletin for Programming Chassis Electronic Control Units (ECUs) With DiagnosticLink.
WI21-0062021-02-26. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. Warranty Information Letter for Detroit NOx Sensor Circuit Fault Codes - Claim Guidelines.
TechTalk80602021-02-03. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; EQUIPMENT. Tech Talk discussion on cgw lost communication with cpc.
TechTalk80932021-02-02. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN; ENGINE AND ENGINE COOLING. Tech Talk discussion on Cummins ISX fault 5865.
TechTalk80222021-02-02. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING; POWER TRAIN. Tech Talk discussion on Modules not powering up after being jumped.
TechTalk76442021-02-02. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on Possible new regen strategy on GHG 17.
SS10344922021-01-28. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. Superseded Service Solution for New Cascadia P4 Coolant Level Wiring Damage. Fault codes can be generated if wiring to the coolant level sensor becomes damaged. This Service Solution has been superseded to service bulletin SB 54-337. Please see the service bulletin for the most current information.
SS1034762update2021-01-26. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This Service Solution has been superseded by Service Bulletin SB54-338. Service Solution for P4 Cascadia Front HVAC Evaporator Freezing. Front evaporator freezes creating ice buildup, reducing airflow through the vents.
WI21-0012021-01-26. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. Warranty Information Letter for Detroit New Service Replacement Engine SRT Update. While validating Standard Repair Times (SRTs) for Detroit's new Gen 5 engine series, DTNA discovered an error in a pre-Gen 5 SRT for the New Service Replacement Engine Program. As a result, DTNA re-studied the SRT and concluded that time for removing/re-installing multiple components (e.g., exhaust manifold/turbo, engine sensor harness, rocker arm assemblies, etc.) should not be included.
SB54-3372021-01-22. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING. Freightliner Service Bulletin for Coolant Level Sensor Wiring Repair. On New Cascadia vehicles, depending on the tension applied to the harness located at the coolant level sensor and its mounting locations, wiring damage can occur, resulting in one or more of the below listed fault codes.
Techtalk66092021-01-03. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk continuing discussion on Optimized Idle batteries dying.

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