A/T - Hard Converter Lock-Up/Hard 1-2 Shift

Hard 1-2 shift or hard torque converter lockup clutch engagement

Topic number LI27.00-P-049253

Version 1

Design group 27.00 General

Date 04-06-2010

Validity Transmission 722.9

Reason for change Remedy revised / Supersedes DTB S-B-27.00/112

Reason for block

Complaint:

The customer complaint of "Hard shift, presumable the 1-2 shift, occurs when moving off" is often received even though the problem is hard engagement of the torque converter lockup clutch (KUB) in the start-off process.

In order to permit a clear diagnosis, restrict the transmission to 1st gear by shifting to position 1.

If a jolt occurs at the point where the state of the torque converter lockup clutch changes from "open" to "slipping", then the cause should be sought in the control of the torque converter lockup clutch.

Cause:

Control of torque converter lockup clutch engagement not optimized.

Remedy:

1. Via DAS menu item "Initial startup", perform transmission software update and then perform SCN coding.

2. Via DAS menu item "KUB adaptation", adapt the torque converter lockup clutch according to the coolant temperature and torque window.

3. Then perform a test drive.





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