WenmarOpen by Wenmar Pro

Service bulletin PIT5878C

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 id10234235
Published by NHTSA2023-04-17
Manufacturer's numberPIT5878C
Manufacturer's date2023-03-23
NHTSA componentEQUIPMENT:ELECTRICAL; VISIBILITY:DEFROSTER/DEFOGGER/HVAC SYSTEM; ENGINE AND ENGINE COOLING

NHTSA's summary

This Preliminary information communicates to the field engineering contacts to assist in the diagnosis of HVAC concerns on the new 2022-2023 HUMMER EV and the 2023 LYRIQ.

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

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

Vehicles listed
CADILLAC LYRIQ2023
GMC HUMMER EV PICKUP2022, 2023

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

Recalls for the same vehicles and component
25V3560002025-05-29. ELECTRICAL SYSTEM: INSTRUMENT CLUSTER/PANEL; EQUIPMENT:ELECTRICAL:INFOTAINMENT:VIDEO (TOUCH)SCREEN/MONITOR/UNIT

A recall listed here may apply to some of the same vehicles. Only the manufacturer can say whether it applies to one vehicle.

Other bulletins for the same vehicles and component
23-NA-1532025-10-25. Service bulletin. The service bulletin advises the tech of a normal transmission shift condition and the delay in throttle response when the throttle plate is opened rapidly and advises the customer that it is normal for the delay.
PIC6578C2025-08-04. Service bulletin. This Preliminary information communicates procedure to relearn window motor when it reverses when expressing up.
N2525023902025-06-02. Service campaign. Service Update. Certain vehicles listed above may require software updates that improve the customer experience and optimize future over-the-air updates. Dealers will perform a comprehensive software update.
24-NA-1642025-04-15. Service bulletin. This bulletin provides information on Wiper Blade Maintenance Tips.
24-NA-1642025-03-06. Service bulletin. This bulletin provides information on Wiper Blade Maintenance Tips.
22-NA-0742025-02-12. Service bulletin. This service bulletin provides service information to technicians on guidelines to replace Oil Cooler, Oil Cooler Lines and Oil Tank if the engine was replaced where large amounts of debris has flowed throughout the oiling system.
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.
09-06-04-026Z2025-01-23. Service bulletin. This bulletin provides information on identifying Non-GM Engine Calibrations for Gasoline Engines using the Tech 2 or GDS 2.
PIT5832S2024-12-16. Service bulletin. This Preliminary information communicates a diagnostic tip on how to resolve a issue if the serial data authentication configuration did not complete correctly.
21-NA-0432024-12-10. 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.