MSD81 Upgrade for BMW N54

This is a mail in service.

You will need to remove your MSD80 DME from your vehicle and mail it to us.

Contact us with any questions.

You can either provide us with the MSD81 DME for the upgrade, or we can supply the MSD81 DME at an additional cost. 

This service is for upgrading your MSD80 DME to an MSD81 DME.

Basic Information
The N54 engine, renowned for its performance, was featured in several BMW models, including:

• BMW 135
• BMW 335
• BMW 335is
• BMW 535
• BMW Z4
• BMW X6

The N54 engine was managed by two types of engine computers: MSD80 and MSD81. These are also referred to as:

• DME (Digital Motor Electronics)
• ECU (Electronic Control Unit)
• ECM (Electronic Control Module)

Problem Description
The MSD80 engine computer is prone to two primary issues:

1. MOSFET Failure
   MOSFETs, crucial electronic components on the MSD80 board, can fail due to age or high-performance demands. When this happens, the car misfires significantly and enters limp mode.

   • A failed MOSFET can cause misfires in either Bank 1 or Bank 2.
     Bank 1 Errors:

     • 29CD: Combustion Misfire, Cylinder 1
     • 29CE: Combustion Misfire, Cylinder 2
     • 29CF: Combustion Misfire, Cylinder 3
     • 30BA: DME Internal Failure

     Bank 2 Errors:

     • 29D0: Combustion Misfire, Cylinder 4
     • 29D1: Combustion Misfire, Cylinder 5
     • 29D2: Combustion Misfire, Cylinder 6
     • 30BB: DME Internal Failure

   • Failed MOSFETs often cause ignition coil pack or Injector damage, so we highly recommend replacing any burnt coils along with the repair.

2. Power Supply Unit (PSU) Failure
   Each bank is powered by a dedicated PSU. Although less common than MOSFET issues, PSU failure results in similar symptoms and error codes as those caused by MOSFET failure.

Solution
Upgrading to the MSD81 engine computer resolves these issues. The MSD81 features enhanced MOSFETs and PSUs, eliminating the weaknesses of the MSD80.

The MSD81 you Receive back from us is a completely 100% plug and play solution.
We also recode your Injectors to the replacement MSD81.

How It Works
Our upgrade service has a 1-2 business-day turnaround. To complete the process, you’ll need to send us:

1. Your MSD80 DME Module

Once we receive these components, we’ll program and ship them back, ensuring a seamless transition to the improved MSD81 system.