Complaint Diverse functional limitations in the vehicle in combination with various warning and fault...

Bulletin number

LI54.21-P-079510

Component

Electrical system

Summary

Complaint Diverse functional limitations in the vehicle in combination with various warning and fault messages in the instrument cluster display. Cause Communication timeouts mean that communication errors may occur in the on-board electrical system, which can result in various fault messages being displayed in the instrument cluster. This could be down to delayed feedback from the drivetrain control unit (N127) (CPC) to other control units networked to the CAN bus. Information: • It may not be possible to attribute any communication errors stored in the control units on the CAN bus to a specific cause. • In rare instances, there may be a brief activation of the yellow warning lamp for engine diagnosis or there may be a sporadic delay with the start enable. • There may not be any specific fault codes present that indicate a specific component. Remedy Do not replace any components!!! 1. Connect charger (see AR54.10-P-1127WT). Note: An adequate voltage from the on-board electrical system battery must be guaranteed for the entire duration of the work procedure. Otherwise the control units could be damaged if an undervoltage occurs. Information: Observe the operating instructions of the charger. Information: Use the charger to ensure an adequate voltage (at least 12.5 V) from the on-board electrical system battery. 2. Connect diagnostic system (see AD00.00-P-2000-06FR). Note: Always use the latest XENTRY Diagnostics software release. Information: Strict compliance with the operation steps in XENTRY Diagnostics is absolutely essential. 3. Select control unit N127 (CPC) via the direct link using XENTRY Diagnosis. Information: To do so, select the following menu items: Control units view → Drive systems → N127 - "Powertrain" control unit (CPC). 4. Update software for control unit N127 (CPC) (see AR54.21-P-0014-01Y). Info: To do so, select the following menu items: Adaptations → Control unit update → Update control unit software. Information: You are then automatically guided through the steps "Update of control unit software" and "SCN coding". Always observe the following operation steps at all times. 5. Disconnect diagnostic device from vehicle (see AD00.00-P-2000-06FR). 6. Disconnect charger from vehicle (see AR54.10-P-1127WT).

Owners of these vehicles have filed 80 complaints in the electrical category.