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Service bulletin 020941001

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 id634977
Published by NHTSA2002-10-11
Manufacturer's number020941001
Manufacturer's date2002-06-01
Replaces990603010A
NHTSA componentUNKNOWN OR OTHER

NHTSA's summary

DIAGNOSTIC TROUBLE CODES B1001, B1271 OR B1780 SET WHEN REPLACING / REPROGRAMMING OTHER MODULES FOR 1999 - 2003 PASSENGER CARS AND TRUCKS WITH CLASS 2 SERIAL DATA COMMUNICATION BETWEEN MODULES. *TT

The document

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

Trouble codes named

B1001, B1271, B1780

Vehicles listed
AM GENERAL HUMMER
BUICK BUICK
CADILLAC CADILLAC
CHEVROLET CHEVROLET
GMC GMC
OLDSMOBILE OLDSMOBILE
PONTIAC PONTIAC

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