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Service bulletins for the 2021 Western Star 6900

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.

76 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
CXA_10_25_Conmet Oil Pan2025-11-05. Other. ENGINE. CX Advocate for ConMet Oil Pan Insert Additional Issues
WI24-0192024-12-04. Warranty extension. ENGINE. Warranty Information letter for Detroit Line or Line Seal, High Pressure Fuel Injector Standard Repair Time Updates
SS1023366-Detroit2024-11-06. Other. ENGINE. Service Solution for Detroit Successful Regen Reference for GHG17 DD Engines
SS1023366-Detroit2024-10-04. Other. ENGINE. Service Solution for Detroit Successful Regen Reference for GHG17 DD Engines
CXA 8_24_Conmet Oil Pan2024-09-07. Other. ENGINE. CX Advocate for ConMet Oil Pan Insert Additional Failures
CXA 8_24_AutoElevate Disa2024-09-07. Other. ENGINE. CX Advocate for AutoElevate Disablement Gen5 Engines
CXA 8_24_AutoElevate and2024-09-07. Other. ENGINE. CX Advocate for benefits of Autoelevate and hydrocarbon faults
CXA 7_24_Conmet Oil Pan2024-08-02. Other. ENGINE. CX Advocate for ConMet Oil Pan Insert Additional Failures
CXA 7_24_AutoElevate Disa2024-08-02. Other. ENGINE. CX Advocate for AutoElevate Disablement Gen5 Engines
SS3144-FTL2024-05-07. Service bulletin. ENGINE AND ENGINE COOLING. Service Solution for DEF Pump Wiring for Cummins CM2450 Engine Controller
SBW49-0202022-03-03. Service bulletin. ENGINE AND ENGINE COOLING. Western Star Service Bulletin for DEF Connector Reinforcement Caps
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.
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.
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.
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.
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-062020-10-13. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING. DDC Technical Service Letter for GHG17 DD Platform Heavy Duty Oil Pan Drain Plug Inserts. Some GHG17 DD Platform Heavy Duty oil pans may experience an issue with the oil pan drain plug insert spinning during removal or installation while completing an oil change. Leaking may also be observed at the drain plug and/or other plugs in the oil pan.
18SP7362020-10-01. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:GASOLINE:BELTS AND ASSOCIATED PULLEYS; ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN. Detroit Diesel Special Publication informing about Heavy Duty Friction Style Belt Tensioner Kit. This heavy duty friction style belt tensioner kit contains the belt tensioner and two M10 bolts to correctly pin the friction style belt tensioner. The M10x80mm bolt is used to pin the engine cooling fan drive arm. The M10x50mm bolt is used to pin the engine accessory drive arm.
20TS-03REV22020-10-01. Service bulletin. ENGINE AND ENGINE COOLING. Revised Technical Service Letter for DD Heavy Duty Platform Belt Tensioner Change. A newly designed, dual-arm friction shoe damping tensioner was implemented for the DD Heavy Duty Platform. The revision includes additional information on retrofit and service kits.
TechTalk76792020-10-01. Service bulletin. ENGINE AND ENGINE COOLING. Tech Talk discussion on repair verification for codes like 'low air flow' when a trailer is not available.
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.
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.
20CSA-102020-07-31. Service bulletin. ENGINE AND ENGINE COOLING. Customer Service Announcement informing that Service Pack (SP) 1 for DiagnosticLinkî 8.12 Standard and Professional is available to download from the Detroit Diesel server.
TS10330142020-07-31. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; FUEL SYSTEM, GASOLINE:DELIVERY:FUEL PUMP; ENGINE AND ENGINE COOLING. Training Solutions for Fuel Leak Found at High Pressure Fuel Pump Weep Hole for Heavy Duty DD Engines. Occasionally we see trucks come in with fuel leaking from the high pressure fuel pump weep hole. This is NOT a defect in the pump and further diagnostics need to be performed to find the root cause.

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