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Service bulletin 020730025

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 id635016
Published by NHTSA2002-10-16
Manufacturer's number020730025
Manufacturer's date2002-06-01
NHTSA componentPOWER TRAIN:AUTOMATIC TRANSMISSION

NHTSA's summary

SUBJECT REGARDING HARSH SHIFTING, DELAYED UPSHIFTS, POSSIBLE CHECK TRANS LAMP ILLUMINATED, POSSIBLE DIAGNOSTIC TROUBLE CODE 21 STORED IN THE TRANSMISSION CONTROL MODULE (TCM) MEMORY. *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.

Components

Transmission and driveline, Automatic transmission

Vehicles listed
CHEVROLET W SERIES1999 to 2000
CHEVROLET W-SERIES2001 to 2003
GMC W SERIES1999 to 2000
GMC W-SERIES2001 to 2003
ISUZU NPR1999
ISUZU NPR2000 to 2003
ISUZU NQR1999, 2000, 2001, 2002, 2003

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
0407300082004-08-14. Service bulletin. AISIN AUTOMATIC TRANSMISSION FLUID SERVICE REMINDER. 2005 ISUZU NPR/NQR INCLUDED. *TT
0307300602004-03-04. Service bulletin. AUTOMATIC TRANSMISSION OIL COOLER FLUSHING ON CERTAIN MEDIUM DUTY TILT CAB MODELS AND COMMERCIAL MODELS INCLUDING MODEL YEAR 2004. *TT
0307300502004-01-05. Service bulletin. APPROVED AISIN AUTOMATIC TRANSMISSION ON-VEHICLE REPAIRS. 2004 MODELS INCLUDED. *TT
0307300352003-12-04. Service bulletin. REPLACEMENT OF OUTPUT FLANGE NUT WHEN SERVICING TRANSMISSION. ALSO INCLUDES 2004 MODELS. *TT
020730025B2003-10-01. Service bulletin. HARSH SHIFTING, DELAYED UPSHIFTS WITH POSSIBLE CHECK TRANS LAMP ILLUMINATED, POSSIBLE DIAGNOSTIC TROUBLE CODE (DTC) 21 SET. TO INCLUDE 2004 MODELS. *TT
020730025A2002-10-10. Service bulletin. HARSH SHIFTING, DELAYED UPSHIFTS, POSSIBLE CHECK TRANS LAMP ILLUMINATED, POSSIBLE DIAGNOSTIC TROUBLE CODE 21 STORED IN TCM MEMORY. *TT
0105C0042002-02-25. Service bulletin. INFORMATION REGARDING AUTOMATIC TRANSMISSION OVERHEAT. *YD
SB9905C0042000-01-04. Service bulletin. VEHICLES EQUIPPED WITH AISIN AUTOMATIC TRANSMISSIONS MAY EXHIBIT A TCM DTC 37. *TT
SB9905C0021999-08-05. Service bulletin. INFORMATION REGARDING THE AISIN AUTOMATIC TRANSMISSION DIAGNOSTIC / CORE FORM. *TT