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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

Bulletins, newest first
18NA3062019-11-25. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA) (US dealers only).
18NA2792019-11-25. Service bulletin. EQUIPMENT:ELECTRICAL. This informational bulletin provides information for dealers/technicians on the process to disable and enable passive unlocking.
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.
17NA0732019-10-28. Service bulletin. EQUIPMENT. This warranty administration bulletin provides information regarding the field action courtesy transportation policy.
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.
PI0592E2019-09-23. Service bulletin. ELECTRICAL SYSTEM. This preliminary information bulletin provides information om Service Programming System (SPS) Error Codes E4398, E4399, E4403, M4404, M4413, E4414, E4423, E4491 or E6961).
090604026R2019-09-23. Service bulletin. ENGINE AND ENGINE COOLING. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
070601016F2019-09-23. Service bulletin. ENGINE AND ENGINE COOLING. This informational bulletin provides information on Internal Engine Noise or Damage After Oil Filter Replacement.
000601026M2019-09-23. Service bulletin. ENGINE AND ENGINE COOLING. This informational bulletin provides information on replacing the intake manifold when the engine is replaced after severe internal engine damage.
16NA1092019-09-23. Service bulletin. STEERING. This technical bulletin provides a procedure inspecting for excess grease or Sealant on the Exterior of the steering gear due to seeing grease or sealant on certain locations on the gear.

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