Mercedes-Benz A220 2020 Technical Service Bulletin # LI27-57_P-0534962 Date: 120522

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

ECO start/stop inoperative, fault code P0944 in transmission control unit

Topic number LI27.57-P-053496

Version 2

Design group 27.57 Oil pump

Date 05-22-2012

Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200

Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.

Complaint:

ECO start/stop inoperative, fault code P0944 in transmission control unit.

Attachments

Cause:

Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.

May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.

Remedy:

Access via fault code P0944; and perform there the following test according to the instructions:

Mercedes-Benz A220 2020 Page 49

Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When

removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.

Important note:

After the test/repair, check and correct the oil level in the transmission.

If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission

sequence number is lower than 3.491.853, then please create a PTSS.

If the fault code is no longer present, perform the following test steps.

Step 1: Check auxiliary oil pump connector and fuse

Step 2: Check supply voltage

Step 3: Check CAN lines

Step 4: Check VGS software and update if necessary, then continue with step 5

Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.

Step 6: Replace auxiliary oil pump

If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.

Symptoms

Control unit/fault code

Work units

Mercedes-Benz A220 2020 Page 50

2020 Mercedes Benz Truck ML 350 Technical Service Bulletin # LI27-57_P-0534962 Date: 120522

2020 Mercedes Benz Truck ML 350 Technical Service Bulletin # LI27-57_P-0534962 Date: 120522

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

ECO start/stop inoperative, fault code P0944 in transmission control unit

Topic number LI27.57-P-053496

Version 2

Design group 27.57 Oil pump

Date 05-22-2012

Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200

Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.

Complaint:

ECO start/stop inoperative, fault code P0944 in transmission control unit.

Attachments

Cause:

Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.

May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.

Remedy:

Access via fault code P0944; and perform there the following test according to the instructions:

2020 Mercedes Benz Truck ML 350 4MATIC (164.186) V6-3.5L (272.967) Page 62

Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When

removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.

Important note:

After the test/repair, check and correct the oil level in the transmission.

If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission

sequence number is lower than 3.491.853, then please create a PTSS.

If the fault code is no longer present, perform the following test steps.

Step 1: Check auxiliary oil pump connector and fuse

Step 2: Check supply voltage

Step 3: Check CAN lines

Step 4: Check VGS software and update if necessary, then continue with step 5

Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.

Step 6: Replace auxiliary oil pump

If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.

Symptoms

Control unit/fault code

Work units

2020 Mercedes Benz Truck ML 350 4MATIC (164.186) V6-3.5L (272.967) Page 63

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

Mercedes Benz C 250 4MATIC (204.085) (CAN) V6-2.5L (272.911) Technical Service Bulletin # LI27-57_P-0534962 Date: 120522

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

ECO start/stop inoperative, fault code P0944 in transmission control unit

Topic number LI27.57-P-053496

Version 2

Design group 27.57 Oil pump

Date 05-22-2012

Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200

Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.

Complaint:

ECO start/stop inoperative, fault code P0944 in transmission control unit.

Attachments

Cause:

Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.

May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.

Remedy:

Access via fault code P0944; and perform there the following test according to the instructions:

2010 Mercedes Benz C 250 4MATIC (204.085) (CAN) V6-2.5L (272.911) Page 15

Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When

removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.

Important note:

After the test/repair, check and correct the oil level in the transmission.

If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission

sequence number is lower than 3.491.853, then please create a PTSS.

If the fault code is no longer present, perform the following test steps.

Step 1: Check auxiliary oil pump connector and fuse

Step 2: Check supply voltage

Step 3: Check CAN lines

Step 4: Check VGS software and update if necessary, then continue with step 5

Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.

Step 6: Replace auxiliary oil pump

If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.

Symptoms

Control unit/fault code

Work units

2010 Mercedes Benz C 250 4MATIC (204.085) (CAN) V6-2.5L (272.911) Page 16

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

Mercedes Benz C 250 (204.052) (CANADA) V6-2.5L (272.921) Technical Service Bulletin # LI27-57_P-0534962 Date: 120522

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

ECO start/stop inoperative, fault code P0944 in transmission control unit

Topic number LI27.57-P-053496

Version 2

Design group 27.57 Oil pump

Date 05-22-2012

Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200

Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.

Complaint:

ECO start/stop inoperative, fault code P0944 in transmission control unit.

Attachments

Cause:

Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.

May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.

Remedy:

Access via fault code P0944; and perform there the following test according to the instructions:

Page 15

Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When

removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.

Important note:

After the test/repair, check and correct the oil level in the transmission.

If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission

sequence number is lower than 3.491.853, then please create a PTSS.

If the fault code is no longer present, perform the following test steps.

Step 1: Check auxiliary oil pump connector and fuse

Step 2: Check supply voltage

Step 3: Check CAN lines

Step 4: Check VGS software and update if necessary, then continue with step 5

Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.

Step 6: Replace auxiliary oil pump

If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.

Symptoms

Control unit/fault code

Mercedes Benz E 550 4MATIC Sedan Technical Service Bulletin # LI27-57_P-0534962 Date: 120522

 Mercedes Benz E 550 4MATIC Sedan Technical Service Bulletin # LI27-57_P-0534962 Date: 120522
2010 Mercedes Benz E 550 4MATIC Sedan (212.090) V8-5.5L (273.970)   Page 63
A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM
ECO start/stop inoperative, fault code P0944 in transmission control unit
Topic number LI27.57-P-053496
Version 2
Design group 27.57 Oil pump
Date 05-22-2012
Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200
Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.
Complaint:
ECO start/stop inoperative, fault code P0944 in transmission control unit.
Attachments
Cause:
Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.
May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.
Remedy:
Access via fault code P0944; and perform there the following test according to the instructions:
Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When
removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.
Important note:
After the test/repair, check and correct the oil level in the transmission.
If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission
sequence number is lower than 3.491.853, then please create a PTSS.
If the fault code is no longer present, perform the following test steps.
Step 1: Check auxiliary oil pump connector and fuse
Step 2: Check supply voltage
Step 3: Check CAN lines
Step 4: Check VGS software and update if necessary, then continue with step 5
Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.
Step 6: Replace auxiliary oil pump
If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.
Symptoms
2010 Mercedes Benz E 550 4MATIC Sedan (212.090) V8-5.5L (273.970)   Page 64
Control unit/fault code
Work units
WIS-References
Attachment
Picture of the valve

Mercedes Benz Truck GLK 350 Technical Problem # LI27-57_P-0534962 Date: 120522 A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM ECO start/stop inoperative, fault code P0944 in transmission control unit

 Mercedes Benz Truck GLK 350 Technical Problem # LI27-57_P-0534962 Date: 120522
A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM
ECO start/stop inoperative, fault code P0944 in transmission control unit
Topic number LI27.57-P-053496
Version 2
Design group 27.57 Oil pump
Date 05-22-2012
Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200
Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.
Complaint:
ECO start/stop inoperative, fault code P0944 in transmission control unit.
Attachments
Cause:
Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.
May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.
Remedy:
Access via fault code P0944; and perform there the following test according to the instructions:
 Mercedes Benz Truck GLK 350 45
Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When
removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.
Important note:
After the test/repair, check and correct the oil level in the transmission.
If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission
sequence number is lower than 3.491.853, then please create a PTSS.
If the fault code is no longer present, perform the following test steps.
Step 1: Check auxiliary oil pump connector and fuse
Step 2: Check supply voltage
Step 3: Check CAN lines
Step 4: Check VGS software and update if necessary, then continue with step 5
Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.
Step 6: Replace auxiliary oil pump
If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.
Symptoms
Control unit/fault code
Work units
 Mercedes Benz Truck GLK 350 46
WIS-References
Attachment
Picture of the valve

Mercedes Benz C 63 AMG Technical Service Bulletin #LI27-57_P-0534962 A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM ECO start/stop inoperative, fault code P0944 in transmission control unit

Mercedes Benz C 63 AMG Technical Service Bulletin #LI27-57_P-0534962
A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM
ECO start/stop inoperative, fault code P0944 in transmission control unit
Topic number LI27.57-P-053496
Version 2
Design group 27.57 Oil pump
Date 05-22-2012
Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200
Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.
Complaint:
ECO start/stop inoperative, fault code P0944 in transmission control unit.
Attachments
Cause:
Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.
May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.
Remedy:
Access via fault code P0944; and perform there the following test according to the instructions:
Date: 1205222010 Mercedes Benz C 63 AMG Sedan (204.077) V8-6.3L (156.985)
 
 
Page 37
Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When
removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.
Important note:
After the test/repair, check and correct the oil level in the transmission.
If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission
sequence number is lower than 3.491.853, then please create a PTSS.
If the fault code is no longer present, perform the following test steps.
Step 1: Check auxiliary oil pump connector and fuse
Step 2: Check supply voltage
Step 3: Check CAN lines
Step 4: Check VGS software and update if necessary, then continue with step 5
Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.
Step 6: Replace auxiliary oil pump
If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.
Symptoms
Control unit/fault code
Work units2010 Mercedes Benz C 63 AMG Sedan (204.077) V8-6.3L (156.985)
 
 
Page 38
WIS-References
Attachment
Picture of the valve

Mercedes Benz S 550 4MATIC Technical Problem #LI27-57_P-0534962 Date: 120522 2010 Mercedes Benz S 550 4MATIC (221.186) V8-5.5L (273.968) Page 41 A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM ECO start/stop inoperative, fault code P0944 in transmission control unit

Mercedes Benz S 550 4MATIC  Technical Problem #LI27-57_P-0534962 Date: 120522
2010 Mercedes Benz S 550 4MATIC (221.186) V8-5.5L (273.968)    Page 41
A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM
ECO start/stop inoperative, fault code P0944 in transmission control unit
Topic number LI27.57-P-053496
Version 2
Design group 27.57 Oil pump
Date 05-22-2012
Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200
Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.
Complaint:
ECO start/stop inoperative, fault code P0944 in transmission control unit.
Attachments
Cause:
Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.
May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.
Remedy:
Access via fault code P0944; and perform there the following test according to the instructions:
Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When
removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.
Important note:
After the test/repair, check and correct the oil level in the transmission.
If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission
sequence number is lower than 3.491.853, then please create a PTSS.
If the fault code is no longer present, perform the following test steps.
Step 1: Check auxiliary oil pump connector and fuse
Step 2: Check supply voltage
Step 3: Check CAN lines
Step 4: Check VGS software and update if necessary, then continue with step 5
Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.
Step 6: Replace auxiliary oil pump
If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.
Symptoms
2010 Mercedes Benz S 550 4MATIC (221.186) V8-5.5L (273.968)    Page 42
Control unit/fault code
Work units
WIS-References
Attachment
Picture of the valve

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM ECO start/stop inoperative, fault code P0944 in transmission control unit Topic number LI27.57-P-053496

Mercedes Benz Truck G 55K AMG (463.271) V8-5.5L SC (113.993)Technical Service Bulletin # LI27-57_P-0534962
Date: 1205222010 Mercedes Benz Truck G 55K AMG (463.271) V8-5.5L SC (113.993)
 
   
Page 14
A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM
ECO start/stop inoperative, fault code P0944 in transmission control unit
Topic number LI27.57-P-053496
Version 2
Design group 27.57 Oil pump
Date 05-22-2012
Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200
Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.
Complaint:
ECO start/stop inoperative, fault code P0944 in transmission control unit.
Attachments
Cause:
Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.
May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.
Remedy:
Access via fault code P0944; and perform there the following test according to the instructions:
Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When
removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.
Important note:
After the test/repair, check and correct the oil level in the transmission.
If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission
sequence number is lower than 3.491.853, then please create a PTSS.
If the fault code is no longer present, perform the following test steps.
Step 1: Check auxiliary oil pump connector and fuse
Step 2: Check supply voltage
Step 3: Check CAN lines
Step 4: Check VGS software and update if necessary, then continue with step 5
Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.
Step 6: Replace auxiliary oil pump
If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.
Symptoms2010 Mercedes Benz Truck G 55K AMG (463.271) V8-5.5L SC (113.993)
 
   
Page 15
Control unit/fault code
Work units
WIS-References
Attachment
Picture of the valve

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

2010 Mercedes Benz Truck GL 350 BLUETEC (164.825) V6-3.0L DSL Turbo (642.820)
Vehicle: All Technical Service Bulletins
A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM
ECO start/stop inoperative, fault code P0944 in transmission control unit
Topic number LI27.57-P-053496
Version 2
Design group 27.57 Oil pump
Date 05-22-2012
Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200
Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.
Complaint:
ECO start/stop inoperative, fault code P0944 in transmission control unit.
Attachments
Cause:
Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.
May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.
Remedy:
Access via fault code P0944; and perform there the following test according to the instructions:
Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When
removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.
Important note:
After the test/repair, check and correct the oil level in the transmission.
If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission
sequence number is lower than 3.491.853, then please create a PTSS.
If the fault code is no longer present, perform the following test steps.
Step 1: Check auxiliary oil pump connector and fuse
Step 2: Check supply voltage
Step 3: Check CAN lines
Step 4: Check VGS software and update if necessary, then continue with step 5
Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)
If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.
Step 6: Replace auxiliary oil pump
If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.
Symptoms
Control unit/fault code
Work units
WIS-References
Attachment
2010 Mercedes Benz Truck GL 350 BLUETEC (164.825) V6-3.0L DSL Turbo (642.820)
Picture of the valve

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM Mercedes Benz C 63 AMG Sedan (204.077) V8-6.3L (156.985)

2010 Mercedes Benz C 63 AMG Sedan (204.077) V8-6.3L (156.985)

Vehicle: Customer Interest

A/T - ECO Start/Stop Inoperative, DTC P0944 Stored In TCM

ECO start/stop inoperative, fault code P0944 in transmission control unit

Topic number LI27.57-P-053496

Version 2

Design group 27.57 Oil pump

Date 05-22-2012

Validity NAG2 FEPlus (722.9) with auxiliary oil pump with code B03 up to transmission sequence number 7.248.200

Reason for change Model series 251 deleted because model series 251 does not have ECO start/stop.

Complaint:

ECO start/stop inoperative, fault code P0944 in transmission control unit.

Attachments

Cause:

Check valve in torque converter housing may be damaged. Leakage between torque converter housing and auxiliary oil pump.

May affect transmissions with transmission sequence numbers starting with -07-xxx xxx.

Remedy:

Access via fault code P0944; and perform there the following test according to the instructions:

Check the check valve in the torque converter housing (in pressure duct) for damage (see pictures in attachment).

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed. When

removing/installing the automatic transmission auxiliary oil pump, observe AR 27.30-P-0651EL.

Important note:

After the test/repair, check and correct the oil level in the transmission.

If no damage is found on the check valve, but a torque converter housing with object number 212 271 0401 is installed and the transmission

sequence number is lower than 3.491.853, then please create a PTSS.

If the fault code is no longer present, perform the following test steps.

Step 1: Check auxiliary oil pump connector and fuse

Step 2: Check supply voltage

Step 3: Check CAN lines

Step 4: Check VGS software and update if necessary, then continue with step 5

Step 5: Visual inspection of check valve; the valve is located in the torque converter housing (see pictures in attachment)

If the check valve is damaged, the torque converter housing and the auxiliary oil pump (component M42) must be re-placed.

Step 6: Replace auxiliary oil pump

If one step resolves the problem, it is not necessary to continue with the remaining test steps. Exception: After step 4 always perform step 5.

Symptoms

Control unit/fault code

Work units

WIS-References

Attachment

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