Notes On Avoiding Damage To Ignition System - AH15.10-P-0002-01V

Engine 133, 139, 152.9, 157, 176, 177, 178, 256.9, 260, 270, 273, 274, 276, 278, 282 

Engine 264 in model 167, 205, 213, 222, 238, 253, 257 

Engine 266.920/940/960/980 in model 169.0/3, 245.2 

Engine 271 

Engine 272 

Shown on engine 272 

Shown on engine 272 

Courtesy of MERCEDES-BENZ USA

Model 906 only 

Disconnect all batteries before working on the ignition system.

Otherwise, the ignition system will be damaged.

All models 

• Before disconnecting the electrical connectors, switch off the ignition and store the transmitter keys outside the transmission range (at least 2 m).
• Disconnect the battery before disconnecting the electrical connector (L) from the ME-SFI [ME] control unit.
• Only install genuine parts into the ignition system.
• Do not operate ignition system if the lines are not fully connected.
• At starting speed or when the engine is running, do not detach the electrical connectors from the ignition coils.
• At starting speed or when the engine is running, do not unplug the ignition coils from the spark plugs.
• Before conducting any operations at starting speed check, e.g. the compression pressure, and turn the key in the EIS [EZS] control unit to the "0" position.

Additionally for model 169, 245: 

• Do not unplug the ignition lines from the ignition coil or the spark plugs at starting speed or when the engine is running.
• Check ignition line including the sheath and replace, if necessary.