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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: Engine are shown. Show all

Bulletins, newest first
TechTalk81262021-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on D20M8 having updates greater than Recall requires in server.
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.
CALFTL01-0032021-02-04. Service bulletin. ENGINE AND ENGINE COOLING. Customer Advisory Letter for Gen 5 DD15 Proactive Turbocharger Replacement.
TechTalk69852021-02-02. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on oil filter.
TechTalk76442021-02-02. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on Possible new regen strategy on GHG 17.
21TS-012021-01-28. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. Technical Service Letter for Detroit Bearing Failures - Standard Diagnostic Times. DTNA is increasing repair strategies for determining the root cause of Detroit DD heavy duty lower end bearing failures. To support this strategy change, Detroit now has two (2) Standard Diagnostic Times (SDTs), easy and difficult, which can be applied to repair orders.
WI21-0032021-01-28. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING; EQUIPMENT ADAPTIVE/MOBILITY. Warranty Information Letter for Detroit Bearing Failures - Standard Diagnostic Times. DTNA is increasing repair strategies for determining the root cause of Detroit DD heavy duty lower end bearing failures. To support this strategy change, Detroit now has two (2) Standard Diagnostic Times (SDTs), easy and difficult, which can be applied to repair orders.
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.
Techtalk77762020-12-31. Service bulletin. VISIBILITY; ENGINE AND ENGINE COOLING. Tech Talk continued discussion on 2021 Cascadia opt idle issues.
18SP7442020-12-08. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING; FUEL SYSTEM, GASOLINE:FUEL INJECTION SYSTEM:FUEL RAIL. Special Publication letter for Two-Filter Fuel System KM59 GEN1 DD15 DD16 Severe Duty High Pressure Fuel Rail Feed Lines Service Kit.
20TS-092020-12-07. Service bulletin. ENGINE AND ENGINE COOLING. Technical Service Letter for SPN 3711 FMI 31 on GHG17 DD15 Trucks.
TechTalk77852020-11-03. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; ENGINE AND ENGINE COOLING. Tech Talk discussion on DL8 CGW connection issues for D20M8.
TechTalk77762020-11-03. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. Tech talk discussion on 2021 Cascadia opt idle issues.
TechTalk77712020-11-03. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. Tech talk discussion on DD harness Chaffe.
TechTalk77502020-11-03. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL; ENGINE AND ENGINE COOLING. Tech Talk discussion on DETROIT D20M8 ASM DELETED.
TechTalk77352020-11-03. Service bulletin. FUEL SYSTEM, OTHER; ENGINE AND ENGINE COOLING. Tech Talk discussion on 1 Aftertreatment System Problem Detected.
20TS-072020-10-21. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; POWER TRAIN:AUTOMATIC TRANSMISSION:CONTROL MODULE (TCM/PCM/TECM); ENGINE AND ENGINE COOLING. 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.
SB09-0382020-10-19. Service bulletin. ENGINE AND ENGINE COOLING. Freightliner Service Bulletin for Air Cleaner Support Bracket Bolt Replacement. On New Cascadia vehicles, the air filter housing rear mounting bracket bolts may be found to be loose or missing. If allowed to continue, this can lead to complete bolt failure which will allow the filter housing to rest on and possibly wear through the valve cover.

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