Friction power of torque converter lockup clutch is too high (FC 2783)
or actuation of torque converter lockup clutch not possible (FC 0741)

Topic number LI27.20-P-055758

Version 11

Design group 27.20 Torque converter

Date 10-07-2015

Validity Vehicles with TRANSMISSION 722.9 (7G-TRONIC

PLUS) from production months 04/2011 to 08/2015
Reason for change Cause and remedy adjusted

Reason for block

Complaint:

FC 2783 (Friction power of torque converter lockup clutch is too high) or FC 0741 (Actuation of torque converter
lockup clutch not possible) stored in transmission control unit. One possible additional customer complaint could be
“poor acceleration" e.g. due to engine intervention.

This can affect all 722.9 transmissions (7G-TRONIC PLUS) from the production months 04/2011 to 08/2015. The two
fault codes can also occur in combination with rom sensor faults (see also the relevant LI). The rom sensor fault is not
connected with this complaint.

Cause:

Cause for TRANSMISSION 722.9 from ID 03.318.709 to ID 03.979.899 or from ID 07.019.944 to ID 07.247.699
Increased wear of torque converter bearing bushing. The cause of this may be a rough microsurface of the journal at
the transmission end.

Cause for TRANSMISSION 722.9 from ID _03.979.899 to ID 03.999.999, from ID 04.000.001 to ID 04.999.999, from
ID 05.000.001 to ID 05.999.999, from ID 06.000.001 to ID 06.572.876, from ID 07.247.699 to ID 07.999.999, from ID
08.000.001 to ID 08.195.199, from ID 10.000.001 to 10.482.481 or from ID 14.000.001 to ID 14.031.596

Possible slight internal leakage at sealing ring between transmission input shaft and torque converter lockup clutch.

Remedy:

Remedy for vehicles with ENGINE 271

Update transmission software. Erase the fault codes in the VGS and reset the lifecycle data of the torque converter
(see below for instructions).

If no newer transmission software is available, proceed as described under "Remedy for vehicles without ENGINE
271".

Remedy for vehicles without ENGINE 271

Remove the transmission and the torque converter and then sand the transmission input shaft with a 15 um microfi-
nishing film as described in the attached instructions (use the finishing film/strip 1x only). The finishing film/polishing
strip can be ordered as a consumable from the GLC.

The torque converter must also be replaced here (please order as per EPC).

Observe the following (the flex plate must be installed):

1.) Clean torque converter mount in crankshaft using brake cleaner.

2.) Remove fretting rust from torque converter mount in crankshaft using suitable emery cloth (grain size: 120).

3.) Again clean torque converter mount in crankshaft using brake cleaner (compressed air if necessary).

4.) Grease mounting pin of torque converter with multi-purpose paste before installation.

Additional note (valid for all remedial methods described here which instruct replacement of the torque converter)
After replacing the torque converter, the lifecycle data of the torque converter must be reset as follows:

10-07-2015 4:48 PM PARKEGL
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Access via XENTRY: VGS - Fully integrated transmission control (Y3/8n4) -> Teach-in processes -> Reset of adapta-
tion values -> Torque converter -> Confirm torque converter replacement with Yes -> Confirm reset of adaptation data
with Yes

Access via DAS: Electronic transmission control (722.9 7G-TRONIC) -> Transmission adaptation -> Reset of adapta-
tion data (torque converter lockup clutch) -> Confirm torque converter replacement with Yes -> Confirm reset of adap-
tation data with Yes

If vehicles with TRANSMISSION 722.9 and ID after 06.572.876, after 10.482.481 or after 14.031.596 are reported
with this complaint, please create a PTSS case.

Attachments

File Description

Working instruction finishing the turbine shaft_en..pdf Working instructions for finishing turbine shaft

Beispielbilder_example pictures.pdf Beispielbilder "Passungsrost innerhalb der Drehmoment-
wandler-Aufnahme der Kurbelwelle"
Example pictures "Fretting corrosion within the torque
converter seat of the crankshaft"

Symptoms

Power transmission / Automatic transmission / Automatic transmission - function / General

Power transmission / Automatic transmission / Automatic transmission - function / Poor start-off performance

Power transmission / Automatic transmission / Automatic transmission - function / Shifts

Power generation / Engine management / Engine performance / No/poor output

Power generation / Engine management / Engine performance / Poor acceleration

Power transmission / Automatic transmission / Automatic transmission - function / Poor shift quality

Parts
Part number ES1/ES2 |Designation Quantity |Note EPC
A 000 986 92 74 15 um microfinishing film/po- | 4 Packing unit corresponds to 1.5m Xx
lish (pack contains 5 strips of 0.30 m) ->
Use strips once only
A 000 989 80 51 |12 Multi-purpose paste 1 Pack contains 100g Xx
Operation numbers/damage codes
Op. no. Operation text Time Damage Note
code
2716104 |For use on TRANSMISSION 722.9
from ID 03.318.709 to ID 03.979.899
or from ID 07.019. 944 to ID 07.247.
699
27287 ** |For use on TRANSMISSION 722.
9 with ID higher than 03.979.899 or
07.247.699
54-7989 D/C GROUND LINE
54-1011 QUICK TEST
61-1072 BELLY PAN
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27-2029 R&R TRANSMISSION (INCLUDES RE-
PLACE TORQUE CONV)

00-8515 CLEAN/SAND DOWN PARTS AS RE-
QUIRED

27-1256 CORRECT ATF
27-1047 ADAPTATION

Validity

Vehicle Transmission
: 722,966
is 722.961
* 722,993

722.903
722.968
722.998
722.909
722.960
722.931
722.999
722,972
722.996
722.906
722.930
722.902
722.971
722.904
122.962
722,950
122.964
722.967
722.969
722.901
722.932
722.907
722.965
722,995
722.963
722.908
722,994
722.997
722.905

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