A/T Controls - Harsh 2-1 Downshift Or 1-2 Upshift

# 04-07-30-040A: Harsh 2-1 Downshift or 1-2 Upshift (Reprogram Transmission Control Module (TCM)) - (Jul 1, 2011)

Subject: Harsh 2-1 Downshift or 1-2 Upshift (Reprogram Transmission Control Module (TCM))

Models:
2004 Chevrolet Epica
with ZF-4HP16 Automatic Transaxle

This bulletin no longer applies to the Chevrolet Optra. This bulletin is being revised to remove the Optra model. Please discard Corporate Bulletin Number 04-07-30-040 (Section 07 - Transmission/Transaxle).

Condition
Some customers may comment on a harsh 2-1 downshift and/or a 1-2 upshift.

Correction
Reprogram the TCM with new calibrations that will improve the shift quality.

Parts Information

Important: Do not attempt to order the software or calibration numbers from GMSPO. The software and calibration numbers are programmed into the TCM via a Techline tool device.





The service software and calibration is included in TIS data version 9.75 broadcast to dealers via GM Access on September 27, 2004 and on TIS 2OOO CD-ROM version 10.0 available October 2004.





Warranty Information
For vehicle repaired under warranty, use the above chart.




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