WenmarOpen by Wenmar Pro

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.

By type

By component

By trouble code

By topic

Bulletins, newest first
PIC64232021-02-16. Service bulletin. ELECTRICAL SYSTEM. This Preliminary Information communication requests information from the technician about vehicles that may have Bluetooth or phone projection issues. Dealer should request as much information from the customer on the concern as possible and fill in the questionaire.
PIE06062021-02-01. Service bulletin. AIR BAGS; ELECTRICAL SYSTEM. This engineering information (EI) is requesting information from technicians to perform the check list provided and contact the engineer listed in regards to the service airbag lamp illuminated on the driver information center (DIC).
090604026S2021-02-01. Service bulletin. EQUIPMENT; EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
040089015V2021-02-01. Service bulletin. EQUIPMENT. This bulletin provides information on Warranty Administration ? Required Operating Procedures - 8 Points (U.S. Only).
010601011L2021-02-01. Service bulletin. ENGINE AND ENGINE COOLING; EQUIPMENT. This informational bulletin provides guidelines and diagnostic/repair information to technicians regarding vehicle engine oil consumption.
20NA2382021-02-01. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; EQUIPMENT; ELECTRICAL SYSTEM:SOFTWARE. This service bulletin provides V153 radio software update information to correct customer concerns of various software issues.
20NA2372021-02-01. Service bulletin. ELECTRICAL SYSTEM:SOFTWARE; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; EQUIPMENT. This service bulletin provides V152 radio software update information to correct customer concerns of various software issues.
20NA2352021-02-01. Service bulletin. EQUIPMENT; EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.. This service bulletin provides information to aid a dealer/customer concern of Radio Unwanted Phantom Touch or Non-Responsive to Touch After Cleaning/Disinfecting Radio Display.
20NA1592021-02-01. Service bulletin. TIRES. This Warranty Administration bulletin is for information on General Motors New Vehicle Tire Warranty Program (U.S. Dealers Only).
18NA3062021-02-01. Service bulletin. EQUIPMENT. This Warranty Administration bulletin provides information for dealers/Service advisors on when and how to submit a Pre-Repair Authorization (PRA).
16NA0192021-02-01. Service bulletin. POWER TRAIN; ELECTRICAL SYSTEM:SOFTWARE. This informational bulletin provides information on Transmission Adaptive Functions and Correcting Low Mileage Harsh Shifts, Slips, or Flares.
N2023205102021-02-01. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; ENGINE AND ENGINE COOLING; EQUIPMENT. Customer Satisfaction Program. Certain vehicles, equipped with a gas engine, may have a condition in which the printed circuit board inside of the water pump may have been manufactured incorrectly potentially causing a water pump failure. The vehicle coolant system temperature is monitored and will display multiple warnings to the customer as coolant temperatures rise. At a set coolant temperature, the MIL will illuminate, DTC P2B85 will set in the engine control module (ECM), the oil pressure gauge will indicate high oil pressure and reduced torque with notification to the driver of reduced power will occur. If the customer continues to drive after this warning and the coolant temperature continues to rise, a chime will occur, the AC will be disabled and an additional message instructing the driver to idle will illuminate. If the customer continues to drive the vehicle after all previous warnings and the coolant temperature continues to rise a message the engine will shut down could occur, and the engine will be shut down. Dealers are to replace the water pump.
PIT5799A2021-01-25. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.. This Preliminary information communicates a cocnern where a flashing spot can intermittently show up on the radio display while in reverse. The PI advises that engineering is investigating the concern.
PIC64232021-01-25. Service bulletin. EQUIPMENT:ELECTRICAL:INFOTAINMENT:BLUETOOTH/WIFI. This Preliminary Information communication requests information from the technician about vehicles that may have Bluetooth or phone projection issues. Dealer should request as much information from the customer on the concern as possible and fill in the questionaire.
PI0754D2020-12-21. Service bulletin. VISIBILITY:GLASS, SIDE/REAR:CRITICAL FASTENERS; VISIBILITY:GLASS, SIDE/REAR. This PI provides information on Rear and Side Tempered Glass Spots (Quench Marks) and that they are a normal characteristic.
990851001E2020-12-21. Service bulletin. EQUIPMENT; STRUCTURE. Thins informational bulletin provides information on Paint-less Dent Repair Process.
060089031F2020-12-21. Service bulletin. POWER TRAIN:AUTOMATIC TRANSMISSION; ENGINE. This service bulletin provides information on OEM and Remanufactured Engine and Automatic Transmission/Transaxle Identification.
000310002L2020-12-21. Service bulletin. EQUIPMENT ADAPTIVE/MOBILITY; EQUIPMENT; WHEELS. This service bulletin provides information on Chemical Staining, Pitting, Corrosion and/or Spotted Appearance of Chromed Aluminum Wheels.
18NA2632020-12-21. Service bulletin. EQUIPMENT:OTHER:OWNERS/SERVICE/OTHER MANUAL. This warranty administration bulletin provide policy information for variable diagnostic time allowances on select labor operations (U.S. Only).
PIP5677E2020-12-14. Service bulletin. POWER TRAIN. This Preliminary information communicates to the dealer technician that the 10L60 and the 10L80 transmissions have been place on a part restriction. Dealers are to contact the Product Quality Center before replacing the transmission assembly.
PIT5782A2020-12-14. Service bulletin. ELECTRICAL SYSTEM; EQUIPMENT. This Preliminary information communicates and issue with programming a replacement side object detection module and engineering is working on the issue.
PIP5677D2020-12-14. 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.
PIT3271K2020-12-14. Service bulletin. WHEELS; TIRES. This Preliminary Information communication provides information to the technician about changing the tire and wheel size on vehicles. General Motors will only support a tire calibration for tires that have been sized, tested and designed for the vehicle in question and its applications. Technician should not use the information that is provided by the antilock braking system tire size selection.
PIT57912020-12-14. Service bulletin. EQUIPMENT:ELECTRICAL:RADIO/TAPE DECK/CD ETC.; EQUIPMENT:APPLIANCE:TV/RADIO/SPEAKERS. This Preliminary information communicates a condition where the radio may display a :connection not availale, please call OnStar agent". This bulletin advises that Engineering is working on a software solution that will prevent the message from displaying when listening to non-SXM sources, but still allow the message to display when a loss of connectivity exists and the user is attempting to play Sirius XM.
1308116001F2020-12-07. Service bulletin. EQUIPMENT; ELECTRICAL SYSTEM; POWER TRAIN:AUTOMATIC TRANSMISSION. The intent of this technical bulletin is to identify aftermarket ALDL or DLC interface devices as potential sources for causing multiple customer concerns that do not have other diagnostic methods to identify them.

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