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Service bulletins for the 2020 Peterbilt 579

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.

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

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Bulletins, newest first
21PBN2022-02-04. Service bulletin. FUEL SYSTEM, DIESEL:STORAGE:TANK ASSEMBLY; ELECTRICAL SYSTEM; EQUIPMENT. Interim Safety Recall – Methane detection system will not warn the operator if the system loses power. The driver could be unaware of an issue with the methane detection system or excessive methane present, increasing the risk of a fire, crash and/or personal injury. The repair procedure will be added when it is available.
R21032022-02-04. Service bulletin. ENGINE AND ENGINE COOLING. Retrofit - The emissions exemption will be expiring on 5/15/2022 for certain pre-production vehicles equipped with PACCAR MX-11 and MX-13 EPA 2021 Emissions engines. Production-level components are now available to make these vehicles compliant.
T0122022-01-06. Service bulletin. POWER TRAIN. Non-Safety Campaign: Drivers of vehicles equipped with PACCAR TX-12 transmissions may experience harsh shifts and gear grinding noise. Premature Main Drive Gear damage may occur due to clutch housing and main case countershaft bearing bore wear.
21PBM2022-01-06. Service bulletin. SERVICE BRAKES, HYDRAULIC. Safety Recall – Work Brake May Unintentionally Disengage – NHTSA ID: 21V906, TC: 2021-713. The work brake (also known as winch brake) may unintentionally disengage during winching operations, releasing the service brakes, increasing the risk of crash or injury. The VECU software will be updated to correctly set the speed interlock parameter.
26-0382022-01-06. Service bulletin. POWER TRAIN. Non-Safety Campaign: Eaton Endurant transmissions may experience premature Main Drive Gear damage due to clutch housing and main case countershaft bearing bore wear. A Clutch Housing Front Cover Kit will be installed to address the issue.
42-0592021-12-03. Service bulletin. ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION MOTOR:CONTROLLER; ENGINE AND ENGINE COOLING:COOLING SYSTEM:FAN; ENGINE AND ENGINE COOLING. Non-Safety Campaign - Vehicles with a Cummins X15 engine and Horton fan drive may set Diagnostic Trouble Code (DTC) 6637 and/or 3838 due to fan speed that results in the fan remaining activated until the power is cycled. A new controller will resolve the issue.
43-0712021-10-05. Service bulletin. FUEL SYSTEM, DIESEL. Fix-As-Fail – Due to undersupply issues, only a limited supply of Diesel Exhaust Fluid (DEF) sensors are available. As a temporary solution, after PACCAR confirms a DEF sensor is not available, a temporary software update will allow a vehicle to continue operation with a failed DEF sensor by disabling the DEF sensor diagnostics.
02-1682021-10-05. Service bulletin. STRUCTURE. Information Only - Rear axle Quarter Fenders with less than two inches of clearance between the top of the quarter fender and the bottom of the trailer/equipment are susceptible to damage. The lack of clearance could result in cracked/broken quarter fenders or complete separation if undetected or un-remedied.
21 PBJ2021-10-05. Service bulletin. EXTERIOR LIGHTING; POWER TRAIN. Safety Recall – Hill Start Assist (HSA) Valve Clearance – NHTSA ID: 21V-648, TC: 2021-521. Crossmember mounted Hill Start Assist valve may not have sufficient clearance to the rear axle, resulting in hose or fitting damage. Damage could cause the loss of rear brake signal, resulting in reduced braking capability and increasing the risk of a crash.
52-0042021-08-05. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; ELECTRICAL SYSTEM:ADAS:BLINDSPOT:SOFTWARE. Fix-as-Fail: Radio does not mute when truck with auto trans is placed in reverse. Software flash resolves issue.
36-0072021-07-06. Service bulletin. ENGINE AND ENGINE COOLING. Non-Safety Campaign - Certain Peterbilt Model 579 vehicles may have an incorrect blind spot sensor installed on the right-hand side.
21PBE2021-07-06. Service bulletin. SERVICE BRAKES, AIR. Safety Recall – TSE Brake Chamber Air Leak – NHTSA ID: 21V328. Meritor brake chambers were built with a misaligned park spring, which may cause a fatigue hole in the diaphragm and an internal air leak. The affected brake chambers will be replaced.
21-PBF2021-07-06. Service bulletin. EXTERIOR LIGHTING. Safety Recall – Interim Notification - The Daytime Running Lamps (DRLs) may turn off while the vehicle is in motion and the headlamps, fog lamps or turn signals are not on. This is non-compliant with Canadian Regulation CMVSS 108, which states that the DRLs must be on while the vehicle is in motion without certain other lamps being activated. This bulletin will be updated when a repair is available.
02-1612021-05-05. Service bulletin. STRUCTURE. Non-Safety Campaign- Chassis Fairings become loose and rattle.
21PBB2021-04-06. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING. Safety Campaign - Cummins Engine Flywheel Capscrews improperly torqued. Cummins Recall C2402.
02-1602021-03-10. Service bulletin. VISIBILITY; EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; VISIBILITY:WINDSHIELD WIPER/WASHER. Information Only – Windshield washer pumps have a high No Trouble Found rate. Washer pumps may fail to spray due to a clogged filter.
32-0182021-03-10. Service bulletin. ENGINE AND ENGINE COOLING. Non-Safety Campaign – Chassis with the City Horn option may generate unexpected alerts. A VECU software update is available to resolve the issue.
32-0172021-03-10. Service bulletin. ELECTRICAL SYSTEM. Non-Safety Campaign – The batteries may drain quickly due to the VECU not going to sleep. Updated VECU software is available to resolve the issue.
116-12021-02-01. Service bulletin. EQUIPMENT. SmartNav 2.0 Hardware retrofit for quality validation and vehicle validation units.
26-0372021-01-06. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; POWER TRAIN; EQUIPMENT ADAPTIVE/MOBILITY. Fix-As-Fail - Prior versions of Eaton Endurant transmission software may be prone to setting Linear Clutch Actuator (LCA) fault codes leading to possible LCA hardware replacement.
26-0352021-01-06. Service bulletin. POWER TRAIN; EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT. Non-safety campaign: Vehicles equipped with an Eaton Endurant 12 speed transmission may experience transmission service lamp activation, no gear engagement from neutral, and/or DTC 511 FMI 7 or 10 is set. Resolution is to update the transmission software and calibrations.
T0112021-01-06. Service bulletin. POWER TRAIN. Fix-As-Fail - Prior versions of PACCAR transmission software may be prone to setting Linear Clutch Actuator (LCA) fault codes leading to possible LCA hardware replacement.
01-0792020-12-05. Service bulletin. ELECTRICAL SYSTEM. Fix as Fail The HVAC system, on model 579 and 567 vehicles manufactured since 1/20/2012 may have inadequate temperature control. The HVAC may intermittently stop blowing cold air, typically after a truck restart. Driver may notice the system returns to normal after key cycle. The remedy is updating HVAC software.
13-0552020-11-05. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; SERVICE BRAKES, AIR. Fix as Fail: Peterbilt has introduced an improved mounting bracket for low mount air tanks for vehicles built between January 01, 2017 and July 06, 2020. Torsional vibration may stress the currently-installed brackets and cause them to fail near the bottom of the frame rail.
14-0272020-10-06. Service bulletin. STRUCTURE; EQUIPMENT. Information only: In 2020, Peterbilt and Kenworth began using the same M10, M12, M16, and M20 frame fasteners on all vehicles. Torque specifications for these fasteners are different from previous fasteners.

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