LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Chevrolet >> 2004 >> Optra Base, Automatic >> Repair and Diagnosis >> Quick Lookups >> Technical Bulletins >> Technical Service Bulletins >> Transmission Control Systems >> Harsh 2-1 Downshift or 1-2 Upshift (Reprogram Transmission Control Module (TCM)) (04-07-30-040A)
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Harsh 2-1 Downshift or 1-2 Upshift (Reprogram Transmission Control Module (TCM)) (04-07-30-040A)

Publication date: 2005-08-11
Reference number: 04-07-30-040A
Supersedes refnos: 04-07-30-040

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

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

TECHNICAL SERVICE BULLETIN

Reference Number(s): 04-07-30-040A, Date of Issue:  Aug 11, 2005
Affected Model(s): 2004 Chevrolet Epica; with ZF 4HP 16 Automatic Transaxle
Supercedes: This bulletin is being revised to remove the Optra model. Please discard Corporate Bulletin Number 04-07-30-040 (Section 07 - Transmission/Transaxle).
NOTE: This bulletin no longer applies to the Chevrolet Optra.

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 2000 CD-ROM version 10.0 available October 2004.

Parts Information

Model Engine Transaxle TCM Software and Calibration Data ID
2004 Chevrolet Epica 2.5L L6 (VIN L, RPO LBK) ZF-4HP 16 ECU-SW No: 6581075568
Cal-No: 658107683

Warranty Information

For vehicle repaired under warranty, use:

Warranty Information

Labor Operation Description Labor Time
K5364 Module, Transmission Control - Reprogram Use Published Labor Operation Time