WenmarOpen by Wenmar Pro

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
SB49-0412020-05-23. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:DIESEL; FUEL SYSTEM, DIESEL. Service Bulletin for Remote-Fill DEF Tank Fill Port Torque Value and Required Lubricant. Some New Cascadia vehicles with chassis fairings have remote-fill Diesel Exhaust Fluid (DEF) tanks which have new instructions to replace the remote fill hose and fitting. Proper torque value is critical, as the remote-fill fittings are plastic and can easily crack if overtightened. The gasket on the fill fitting is sensitive to improper installation, and can get pinched, resulting in a DEF leak.
WI20-0042020-04-23. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. Warranty Information Letter for Warranty Long Block Program Change. The Detroit Reman Long Block Program has expanded. The expansion reduces complexity in ordering reman engines and promotes stocking reman engines to meet uptime commitments.
SS10346862020-04-09. Service bulletin. ENGINE AND ENGINE COOLING; POWER TRAIN. Service Solution for P4 New Cascadia with Manual Transmissions Does Not Use Bottom Of Clutch Switch For Starting. On the prior P3 Legacy Cascadia vehicles with manual transmission, the Bottom of Clutch (BOC) switch could be uses as an interlock for the engine crank circuit. If programmed in the SAM Cab, the engine crank circuit would require the clutch to be fully depressed in order for the engine to crank. P3 also offered a neutral switch as an interlock that could be used instead of the BOC and would require the transmission to be neutral in order for the engine to crank. P4 New Cascadia only offers the neutral switch as the interlock for engine crank.
SS10346822020-03-31. Service bulletin. ENGINE AND ENGINE COOLING. Service Solution for Updated Common Telematics Platform (CTP) Installation and Activation Procedure. Some new CTPs being installed in the field have failed to activate and do not communicate with Detroit Connect back end. The activation of the CTP requires that the VIN and CTP serial number pair is transmitted from DiagnosticLink to the Detroit Connect registration server. When using the old procedure, there may be some factors that may prevent that VIN and CTP Serial Number pairing data from uploading to the server.
20CSA-042020-03-22. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. Customer Service Announcement saying that Service Pack (SP) 3 for DiagnosticLink® 8.11 Standard and Professional will be available for download from the Detroit Diesel server.
20TS-022020-03-06. Service bulletin. ENGINE AND ENGINE COOLING. Technical Service Letter for DD Platform Heavy Duty, Metal in the Oil and Oil Filter. Some engine component failures can cause metallic debris to circulate throughout the engine lubrication system. Although the oil filter will capture most of this debris, some debris may enter the clean side of the lubrication system during oil filter bypass. Detroit has created a lubrication system cleaning and flushing procedure to address this problem.

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