Service bulletins for the 2021 Cadillac CT4
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.
813 on file from NHTSA, as of 2026-10-19.
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By component
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Only bulletins with component: Electrical system are shown. Show all
| PIC6444 | 2021-09-13. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM. This Preliminary information communicates a possible SIM issue with vehicles in the middle east. |
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| PIC6443 | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a condtion with service parts and a software anomaly that does not allow them to be programmed to the vehicle. The S165 Infotainment switch inventory will be reworked and released back to service. |
| PIC6384G | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon. |
| PIC6384H | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM; STRUCTURE. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon. |
| PIC6442 | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY THERMAL:MANAGEMENT:SOFTWARE. This Preliminary information communicates that a condition exits that can cause the Drivers Information Center to be blank on startup and Engineering is investigating the concern. |
| PIT5698B | 2021-09-13. Service bulletin. ELECTRICAL SYSTEM:ADAS:BLINDSPOT:SENSORS. This Preliminary information communicates additional information on how a LIN bus operates and diagnostic tips when working on a LIN bus. |
| PIE0643 | 2021-08-09. Service bulletin. ELECTRICAL SYSTEM; ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the Malfunction Indicator Lamp (MIL) illuminated on Driver Information Center (DIC). |
| 21NA131 | 2021-08-09. Service bulletin. SEATS:FRONT ASSEMBLY:POWER ADJUST; ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of Memory Seat Module Does Not Adjust. |
| 20NA178 | 2021-07-19. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of Service Driver Assist and/or Take Steering Messages on Start-up, Advanced Driver Assist Systems (ADAS) Features Not Available. |
| 19NA044 | 2021-07-19. Service bulletin. ELECTRICAL SYSTEM; ENGINE. This service bulletin provides information on the cold start control system in DI engines to reduce cold start emissions and improve fuel economy. |
| 18NA279 | 2021-07-19. Service bulletin. LATCHES/LOCKS/LINKAGES; ELECTRICAL SYSTEM. This service bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking. |
| 21NA124 | 2021-07-06. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides diagnostic tips/steps on testing for possible EVAP leaks in the system to correct a customer concern of an MIL Illuminated with DTCs P0442 and/or P0455 Set. |
| N202307080 01 | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM. Service Update Bulletin (Labor Codes Added). Certain vehicles may have a condition where the engine control module (ECM) software allows the Auto Stop to occur at a state of charge below 65%. Auto Stop is supposed to be inhibited at 65% to protect against excessive battery wear and discharge. Dealers are to reprogram the ECM. |
| PIC6384F | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM; STRUCTURE. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon. |
| PIC6437 | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates the Radio may stay on after ignition off and door opened if there is an Over The Air update pending and to review SI document ID 5778263 for Over The Air update description and operation. |
| PIC6384E | 2021-06-14. Service bulletin. ELECTRICAL SYSTEM; STRUCTURE. This Preliminary information communicates a parts restriction is in place for the Body Control Module on 2020 Cadillac CT4, CT5, Chevrolet Corvette, Suburban, Tahoe and GMC Yukon. |
| N202307080 | 2021-05-24. Service bulletin. ELECTRICAL SYSTEM. Service Update Bulletin. Certain vehicles may have a condition where the engine control module (ECM) software allows the Auto Stop to occur at a state of charge below 65%. Auto Stop is supposed to be inhibited at 65% to protect against excessive battery wear and discharge. Dealers are to reprogram the ECM. |
| PIT5782C | 2021-05-17. Service bulletin. ELECTRICAL SYSTEM; BACK OVER PREVENTION. This Preliminary information communicates and issue with programming a replacement side object detection module and engineering is working on the issue. |
| PIC6433A | 2021-05-17. Service bulletin. ENGINE AND ENGINE COOLING:ENGINE:ENGINE CONTROL MODULE (ECU/ECM); ELECTRICAL SYSTEM:PROPULSION SYSTEM:TRACTION BATTERY:MANAGEMENT SYSTEM/ENERGY CONTROL MODULE (BMS/BECM). This Preliminary information communicates that a service theft deterrent message may display with no DTC's. OnStar turned off the ECM read request to prevent re-occurrence. |
| 21NA068 | 2021-05-10. Service bulletin. ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER. This warranty administration bulletin provides policy information requirements applicable to key fob replacement under the New Vehicle Limited Warranty or under a Replacement Parts Warranty on 2021 and newer model year vehicles with RPO ATH (U.S. Only). |
| 21NA061 | 2021-05-10. Service bulletin. ELECTRICAL SYSTEM:IGNITION:ANTI-THEFT:IMMOBILIZER/PROXIMITY:KEY/SENDER. This service bulletin provides information for dealers on Using EL-52545 When Diagnosing PEPs Transmitter Key Fobs (North America ONLY). |
| 21NA060 | 2021-05-10. Service bulletin. ELECTRICAL SYSTEM. This service bulletin describes the TLC/SPS2 Module Programming Requirements for Vehicles Using GM?s New Vehicle Intelligence Platform (VIP) Module Architecture. |
| 20NA132 | 2021-05-03. Service bulletin. ELECTRICAL SYSTEM. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements. |
| 20NA123 | 2021-05-03. Service bulletin. ELECTRICAL SYSTEM. This service bulletin provides repair information to correct a customer concern of a Malfunction Indicator Lamp (MIL) Illuminated with DTCs U1961, U1983 setting. |
| PIT5817A | 2021-04-19. Service bulletin. ELECTRICAL SYSTEM. This Preliminary information communicates and issue with a SES MIL and the BCM keeping the ignition main relay on after the vehicle is turned off. Dealers are to replace the BCM. |
The summaries are NHTSA's. Each bulletin's page links NHTSA's copy of the manufacturer's document.