Date: 070116

Date: 070116
2000 Mercedes Benz Truck ML 55 AMG (163.174) V8-5.5L (113.981) 311
A/T - Limp Home Mode/DTC's 2502/2505/P0894/P2711
Date: January 16, 2007
Order No.: T-B-27.60/89a
Supersedes: T-B-27.60/89 dated Nov. 27, 2006
Group: 27
Revision History
Revision Date Purpose
a 1/16/07 Technical Content Revised
- 11/27/06 Initial issue
SUBJECT:
All Light Truck Models Equipped with 722.9 Transmission (7G-Tronic)
Fault Codes 2502, 2505, P0894 or P2711
If you receive reports in the above model vehicles of the automatic transmission being in limp-home mode or having no power transfer from the
transmission together with fault codes 2502, 2505 or P0894, P2711, these codes must be processed according to the vehicle symptoms. First,
attempts must be made to reproduce the problem.
If the above fault codes are stored in connection with shift quality complaints, please proceed according to the Diagnostic Tree posted on Star
TekInfo -> EDAC -> Diagnostic Guide for 722.9 NAG 2 (7G-Tronic) Transmission.
If the fault codes are stored together with loss of power transfer, proceed with the below solutions per the respective possible cause.
Cause 1: K1 piston is damaged (adaptation data for the 2-3 shift may be at the positive limit).
Solution 1: If the complaint can only be reproduced for the 2-3 upshift or if third gear can not be reached, there is a defect of the K1 piston.
- Replace the complete multi-disc clutch K1 as per the parts list.
- Reset the adaptation data.
Cause 2: Tolerance in the electrohydraulic control unit (valve body) may not be optimal.
Solution 2: If the K1 multi-disc clutch is not responsible for the concern, replace the electrohydraulic control unit (valve body) and perform initial
startup.
NOTE:
When diagnostic events lead to a transmission or valve body replacement, please refer to DTB P-B-27.00/38d for the proper completion of the

WSG pre-authorization requirements.