Notes on avoiding damage to ignition system - AH15.10-P-0002-01V

Engine 157, 272, 273, 276, 278 

• Before disconnecting the connector (R) at the ME-SFI [ME] control unit (N3/10), turn the key in the ignition switch (EIS [EZS] control unit) to the "0" position.
• Disconnect the battery before disconnecting the connector (L) at the ME-SFI [ME] control unit (N3/10).
• Only install original ignition system components.

  Shown on engine 272 

  Fig 1: Identifying ME-SFI [ME] Control Unit & Connectors

  Courtesy of MERCEDES-BENZ USA
  Fig 2: Identifying Ignition Coil And Spark Plug Connector

  Courtesy of MERCEDES-BENZ USA
• Do not run the ignition system without fully connected lines or without the spark plug connector (a).
• Do not disconnect the connectors at the ignition coils (T1/1 to T1/8) at starting speed or when the engine is running.
• Do not take off the ignition coils (T1/1 to T1/8) from the spark plugs at starting speed or when the engine is running.
• Before working at starting speed, for example, check the compression pressure, turn the key in the EIS [EZS] control unit to the "0" position.