WenmarOpen by Wenmar Pro

Service bulletin PIC6440

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.

The communication, as NHTSA indexes it (as of 2026-10-19)
TypeService bulletin
NHTSA id10201179
Published by NHTSA2021-09-13
Manufacturer's numberPIC6440
Manufacturer's date2021-07-01
NHTSA componentVISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM:FAN/MOTOR; EQUIPMENT

NHTSA's summary

This Preliminary information communicates that a calibration change was made starting with the 2018 model year so that the rear HVAC fan speed will also control the front fan speed.

The document

The document is the manufacturer's. This site does not hold it. NHTSA files a document at one of these two addresses; we have not asked NHTSA which.

Components

Equipment and accessories, Glass, wipers and mirrors, Heating and air conditioning

Vehicles listed
CADILLAC CT62018, 2019, 2020

Listing a model year does not mean every vehicle of it is concerned: the document says which.

Other bulletins for the same vehicles and component
21-NA-0432025-02-12. Service bulletin. This bulletin advises the dealers to maintain the vehicle stock on hand by doing a full inspection on the vehicles before being sold (prepping) to the customer.
PI0754G2024-08-17. Service bulletin. This PI provides information on Rear and Side Tempered Glass Spots (Quench Marks) and that they are a normal characteristic.
16-NA-3422024-08-13. Service bulletin. This service bulletin provides a procedure to check the rearview mirror coax connector for looseness by disconnecting and reconnecting the electrical connector to correct the customers concern for the rearview mirror video screen displaying blue.
16-NA-3422024-07-16. Service bulletin. This service bulletin provides a procedure to check the rearview mirror coax connector for looseness by disconnecting and reconnecting the electrical connector to correct the customers concern for the rearview mirror video screen displaying blue.
23-NA-0642024-05-02. Service bulletin. This service bulletin provides information on the Transport Mode Feature, also known as Logistics mode, which is used to increase the 12V Battery stand time of the vehicle during transit and or long period of stand time at the dealerships.
20-NA-1322024-04-23. Service bulletin. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
17-NA-0522024-04-23. Service bulletin. This bulletin updates the position of General Motors on refinishing aluminum wheels. GM has determined that wheel refinishing under warranty will no longer be performed.
20-NA-1322024-04-05. Service bulletin. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
23-NA-1032024-03-29. Service bulletin. This service bulletin provides information on submitting quality Photos of Various Vehicle Concerns to the GM Technical Assistance Center (TAC).
11-00-89-005X2024-03-19. Service bulletin. This Warranty Administration bulletin provides information on Dealer Empowerment for Goodwill, Customer Enthusiasm and Policy (U.S. Only).