System Components

MS S54 Engine Control Module:  The MS S54 ECM features a single printed circuit board with two 32-bit microprocessors.

The task of the first processor is to control:

• Engine Load
• Electronic Throttle (EDR)
• Idle actuator
• Ignition
• Knock Control

The task of the second processor is to control:

• Air/Fuel Mixture
• Emission Control
• Misfire Detection
• DMTL

Fig 1: Identifying MS S54 Engine Control Module

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 2: Identifying MS S54 Engine Control Module Connector Terminals

Courtesy of BMW OF NORTH AMERICA, INC.

The 134 pin MS S54 Engine Control Module is manufactured by Siemens to BMW M specifications. The ECM is the SKE (standard shell construction) housing and uses 5 modular connectors. For testing, use the Universal Adapter Set (break-out box) Special Tool: # 90 88 6 121 300.