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Service bulletins for the 2020 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.

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

By type

By component

By trouble code

By topic

Only bulletins with component: Transmission and driveline are shown. Show all

Bulletins, newest first
20NA1072020-06-22. Service bulletin. POWER TRAIN. This informational bulletin advises the technician not to replace the prop shaft if a small amount of grease is found leaking out.
PIE0538B2020-05-04. Service bulletin. POWER TRAIN. This engineering information (EI) ends the need for information from the field regarding 8 speed transmission shift quality.
PIC6395A2020-04-13. Service bulletin. POWER TRAIN. This Preliminary information communicates a parts restriction is in place for the Automatic Transmission Control on 2020 Cadillac CT4, and CT5.
PIP5702A2020-04-13. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that the 2020 Cadillic CT5 T93 transmission control module for the 10L80 10 speed transmission is on restriction through the Product Quality Center. Dealers are advised to contact the Product Quality Center if diagnostics has lead to replacement of the transmission control module.
PIP5700B2020-04-13. Service bulletin. ELECTRICAL SYSTEM; POWER TRAIN. This Preliminary information communicates to the dealer technician that the part numbers for the internal wiring harnesses for the 8 speed RWD transmissions are not listed in the Electronic Parts Catalog. Technicians are to refer to the information provided in this document to obtain the internal wiring harness part numbers by application.
PIP5677C2020-03-09. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that the 10L60, 10L80 and the 10L90 transmissions have been place on a part restriction. Dealers are to contact the Product Quality Center before replacing the transmission assembly.
PIP5677B2020-03-09. Service bulletin. POWER TRAIN; EQUIPMENT. This Preliminary information communicates to the dealer technician that the 10L60, 10L80 and the 10L90 transmissions have been place on a part restriction. Dealers are to contact the Product Quality Center before replacing the transmission assembly.
PIE0538A2020-03-09. Service bulletin. EQUIPMENT; POWER TRAIN. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to 8 speed transmission shift quality.
PIP5700A2020-02-10. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM. This Preliminary information communicates to the dealer technician that the part numbers for the internal wiring harnesses for the 8 speed RWD transmissions are not listed in the Electronic Parts Catalog. Technicians are to refer to the information provided in this document to obtain the internal wiring harness part numbers by application.
PIP57002020-02-10. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION. This Preliminary information communicates to the dealer technician that the part numbers for the internal wiring harnesses for the 8 speed RWD transmissions are not listed in the Electronic Parts Catalog. Technicians are to refer to the information provided in this document to obtain the internal wiring harness part numbers by application.
990420002K2019-11-25. Service bulletin. POWER TRAIN. This informational bulletin provides information on Driveline Clunk Noise and what is acceptable and what is considered normal operations.
16NA3612019-11-25. Service bulletin. POWER TRAIN. This informational bulletin explains possible normal condition of a flare from 1st to 2nd, even if the trans had been repaired for the flare and its still noticed.
16NA3382019-11-25. Service bulletin. POWER TRAIN. This Bulletin provides guidelines for Dealers Not Required and for Dealers Required to Contact the PQC for engine or transmission assembly replacement and explains the PQC process, GWM Transaction submission, vehicle service record retention and proper handling of assembly returns.
PIP5677A2019-11-12. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that the 10L60, 10L80 and the 10L90 transmissions have been place on a part restriction. Dealers are to contact the Product Quality Center before replacing the transmission assembly.
PIE05382019-10-28. Service bulletin. POWER TRAIN. This engineering informational bulletin is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to 8 speed transmission shift quality.
PIP56772019-10-15. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that the 10L60, 10L80 and the 10L90 transmissions have been place on a part restriction. Dealers are to contact the Product Quality Center before replacing the transmission assembly.

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