Service bulletins for the 2020 GMC Sierra
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.
1990 on file from NHTSA, as of 2026-10-19.
By type
By component
By trouble code
By topic
| 21NA238 | 2022-06-21. Service bulletin. POWER TRAIN; FUEL SYSTEM, GASOLINE. This technical bulletin provides a procedure to inspect the front pump of the transmission for a possible leak. |
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| 21NA228 | 2022-06-21. Service bulletin. ELECTRICAL SYSTEM:PROPULSION SYSTEM:CHARGING:MODULE:ONBOARD (OBCM). This bulletin provides a procedure to program the BCM to correct the customers concern of RKE idle Time-out. |
| 21NA219 | 2022-06-21. Service bulletin. EQUIPMENT. This informational bulletin provides information for dealers/technicians on an elevated idle feature. |
| 21NA214 | 2022-06-21. Service bulletin. POWER TRAIN; POWER TRAIN:AUTOMATIC TRANSMISSION. This technical bulletin provides repair information to correct a customer concern of Service Engine Soon Lamp being illuminated. They may also comment on multiple transmission issues including harsh or delayed shifts, slip, surge, shudder, noise, whine, growl, shake and/or vibration. As well as the exhaust brake not working or that they do not feel it. Technicians may find DTCs P2002, P2463, P2459, P144E, P0421, P0422, P0106 P20EE, P129F, P16F3, P20FF, P226D, P249D, P249E, P11CC and / or P11D5. |
| 21NA182 | 2022-06-21. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.. This service bulletin provides repair information to correct a customer concern of Radio System Settings Lost or Returning to Default Values. |
| 21NA149 | 2022-06-21. Service bulletin. ENGINE AND ENGINE COOLING. This technical bulletin provides repair information to correct a customer concern of Engine Wire Harness Chafing. |
| 21NA135 | 2022-06-21. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This service bulletin provides information to inform dealership personnel about Law Enforcement and Government vehicles that request to disable or enable content. |
| 21NA275 | 2022-06-21. Service bulletin. WHEELS; SERVICE BRAKES. This service bulletin provides repair information to correct customer concerns of Rear Wheel Lock Up, ABS Event, Loud Bang and a Flashing ?D? on Driver Information Center (DIC) when Lightly or Moderately Accelerating Forcing an 8-7 or 8-6 Downshift. |
| 21NA214 | 2022-06-21. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; EQUIPMENT; ENGINE AND ENGINE COOLING. This technical bulletin provides repair information to correct a customer concern of Service Engine Soon Lamp Illuminated, Harsh or Delayed Transmission Shifts Including Slip, Surge, Shudder, Noise, Whine, Growl, Shake and/or Vibration, DTCs P2002, P2463, P2459, P144E, P0421, P0422, P0106 and/or P20EE Set Current or in Recent History. |
| 21NA113 | 2022-06-21. Service bulletin. ELECTRICAL SYSTEM; ENGINE AND ENGINE COOLING:ENGINE:GASOLINE:TURBO/SUPERCHARGER; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE. This technical bulletin provides a procedure to perform a learn procedure for the turbo actuator. |
| 21NA095 | 2022-06-21. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:EXHAUST SYSTEM:MANIFOLD/HEADER/MUFFLER/TAIL PIPE. This technical bulletin provides a procedure to seal the exhaust at the UFSCR and Tailpipe flange. |
| 20NA203 | 2022-06-21. Service bulletin. EQUIPMENT; ENGINE AND ENGINE COOLING:ENGINE:DIESEL. This informational bulletin explains how the regen works for the DEF system and how it works at different levels. |
| 20NA188 | 2022-06-21. Service bulletin. SERVICE BRAKES; EQUIPMENT ADAPTIVE/MOBILITY; BACK OVER PREVENTION. This technical bulletin provides repair information to correct a customer concern of Rear View Camera Image Flickers When Brake Lamps or Turn Signals are On. |
| 20NA110 | 2022-06-21. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:DIESEL; FUEL SYSTEM, DIESEL:DELIVERY:FUEL PUMP; EQUIPMENT ADAPTIVE/MOBILITY. This service bulletin provides service information for a DEF pump that is unable to build pressure after replacement. |
| 20NA090 | 2022-06-21. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM):SOFTWARE. This informational bulletin provides a way for the technician to identify if the ECM has been modified. |
| 20NA043 | 2022-06-21. Service bulletin. EQUIPMENT; FUEL SYSTEM, GASOLINE:FUEL INJECTION SYSTEM:MANIFOLD PRESSURE (MAP) SENSOR. This informational bulletin advises the technician to not replace the TMAP sensor, clean it using air or harsh chemicals but allow time for the sensor to thaw. |
| PIP5358B | 2022-06-13. Service bulletin. STRUCTURE. This Preliminary Information communication provides information to the technician about vehicles that have an unusual noise and is difficult to identify, isolate or pinpoint. Technician should get record a sound clip or take a video of the noise for assessment by engineering. Technician will need to call General Motors Technical Assistance Center for further assistance. |
| PIP5856 | 2022-06-13. Service bulletin. FUEL SYSTEM, DIESEL. This Preliminary information communicates provides information to the technician on the use of R-99 or R-95 Renewable diesel fuel. |
| PIT5734E | 2022-06-13. Service bulletin. VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM. This Preliminary information communicates an issue with poor heater performance and advises dealerships to inspect the heater core inlet and outlet hoses for being twisted or kinked. |
| PIT5918 | 2022-06-13. Service bulletin. EXTERIOR LIGHTING:HEADLIGHTS. This Preliminary information communicates an issue where GM Accessory Illuminated Emblem may cause an issue with the left headlight/turn signal and dealership are to disable the Accessory Illuminated Emblem until a fix is available. |
| PIT5195G | 2022-06-13. Service bulletin. ELECTRICAL SYSTEM:INSTRUMENT PANEL:SPEEDOMETER/ODOMETER. This Preliminary Information communication provides information to the technician about vehicles that the speedometer needle appears to be inaccurate. Dealer should advise the customer the specification for speedometer needle accuracy is +/- 2 MPH at any given speed when looking straight at the needle. |
| PIT5745D | 2022-06-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates and issue with the memory seat module waking up the low speed GM lan bus and causing a battery draw. |
| PIT5914 | 2022-06-13. Service bulletin. BACK OVER PREVENTION:DISPLAY FUNCTION; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.. This Preliminary information communicates a concern on some 2020 Silverado and Sierra trucks where the radio display will go blank when trying to open the trailering app. Engineerng has root caused the issue, and is working on a software fix. |
| PIP5851 | 2022-06-13. Service bulletin. FUEL SYSTEM, GASOLINE. This Preliminary information communicates to technicians a replacement DEF tank may have been assembled with the incorrect harness. |
| PIT5809C | 2022-06-13. Service bulletin. BACK OVER PREVENTION; STEERING. This Preliminary information communicates an issues with a pop, clunk, knock, rattle type noise heard from the steering column over bumps and ask dealerships to replace the upper column shaft. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.