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Service bulletin 15521

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 id10089427
Published by NHTSA2017-01-24
Manufacturer's number15521
Manufacturer's date2015-12-01
NHTSA componentELECTRICAL SYSTEM:12V/24V/48V BATTERY

NHTSA's summary

15521 - CUSTOMER ADVISORY LETTER. THIS LETTER IS BEING SENT TO BRING TO THE CUSTOMER'S ATTENTION FEATURES THAT ARE COVERED IN THE VEHICLE'S OWNER MANUAL IN SITUATIONS WHERE THE CUSTOMER VEHICLE SIDE DOORS WILL NOT OPEN FROM INSIDE AND OUTSIDE THE VEHICLE DUE TO LOW OR NO BATTERY VOLTAGE. DEALERS ARE ALSO INSTRUCTED THAT IN CORRELATION WITH THIS CUSTOMER ADVISORY LETTER, A WEB-BASED TRAINING COURSE WILL BE REQUIRED FOR ALL CADILLAC AND CHEVROLET SALES CONSULTANTS, SALES MANAGERS, SERVICE CONSULTANTS, SERVICE MANAGERS, AND FIELD STAFF BEGINNING Q1 2016 VIA THE GM CENTER OF LEARNING.

The document

No address for NHTSA's copy can be built for this communication. Ask the dealer for it by the manufacturer's number.

Components

Electrical system, 12-volt battery

Vehicles listed
CADILLAC CTS2011, 2012, 2013, 2014
CADILLAC ELR2014, 2015, 2016
CADILLAC XLR2004, 2005, 2006, 2007, 2008, 2009
CHEVROLET CORVETTE2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014, 2015, 2016

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
20-NA-1322024-04-05. Service bulletin. This warranty administration bulletin provides policy information on the requirements for 12V battery testing and warranty replacements.
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PIT5074G2023-12-11. Service bulletin. Terminal Test Probe And Replacement Terminal.
1408117001a2023-12-11. Service bulletin. Unable to Clear BCM DTCs After Completing Repair
1408420012023-12-11. Service bulletin. Additional Diagnostic Tips for Headlamp Inoperative or Intermittent Conditions
20NA1322021-12-20. Service bulletin. This warranty administration bulletin provides policy information on the requirements for battery testing and warranty replacements.
PIC64392021-09-13. Service bulletin. This Preliminary information communicates a diagnostic tip to dealership technicians when diagnosing a B1517 DTC.
150603002H2021-04-16. Service bulletin. Original Equipment Batteries Part Number and ACDelco Replacement Battery Approved Warranty Part Numbers Correct battery cold cranking amperage (CCA) ratings and type are critical for proper test results when using the EL-50313. Access to the battery specification label, which contains the OEM part number and CCA rating and type, may be difficult without component removal. Refer to the table below for the original equipment ratings and part numbers used to set up a proper battery test. There has been some confusion as to the correct ACDelco battery warranty replacement. Refer to the table below for the correct battery warranty replacement. The correct ACDelco battery warranty replacement in the catalog is designated by the "Original Equipment Replacement" note in the description field.
19NA2422020-06-22. Service bulletin. This informational bulletin announces the availability of a High Voltage battery pack refurbish kit when the battery pack assembly needs to be replaced and information on how dealers can obtain the refurbish kit.
PI0798A2019-11-25. Service bulletin. This preliminary information bulletin provides a procedure to correct a condition of a Check Engine Light with DTC P0C4A that Sets immediately after a repair to the High Voltage battery cooling system that involves draining/refilling of coolant.