Remove/Install Ignition Coils - AR15.12-P-2003MRA

Engine 274.9 in model 205 

Engine 274.9 in model 253 

Courtesy of MERCEDES-BENZ USA

	Risk of injury.  Skin or eye injuries may result when handling hot or glowing objects.	Wear protective gloves, protective clothing and safety glasses, if necessary.	AS00.00-Z-0002-01A
	Risk of death  when working on component parts and systems with U > = 30 V alternating voltage (AC) or U > = 60 V direct voltage (DC)	Do not touch damaged or defective live component parts and lines or non-insulated electrical connections and lines.	AS00.00-Z-0035-01A
	Information on preventing damage to electronic components due to electrostatic discharge		AH54.00-P-0001-01A
	Notes on avoiding damage through contamination and foreign objects		AH00.00-P-5000-01A
	Notes on avoiding damage to ignition system		AH15.10-P-0002-01V
	Remove/install
1	Switch off ignition and store transmitter key outside of transmission range (min. 2 m)
2	Remove upper engine cover
3	Unclip coolant vent line (4) from bracket
4	Remove screws (3)	Screw/bolt, ignition coil to cylinder head cover	*BA15.10-P-1001-04A
5	Release and disconnect electrical connectors ignition coils (T1/1, T1/2, T1/3 and T1/4)
6	Pull ignition coils (T1/1, T1/2, T1/3 and T1/4) together with spark plug connectors (a) up and off and take out	Installation:  To reduce the force required for connection and disconnection, apply the spark plug connector grease prior to installing the spark plug connector (a). Otherwise the spark plug connector will be damaged during renewed removal. Installation:  Discharge approx. Fill 1 g of spark plug connector grease into the spark plug connector (a). Spark plug connector grease	*BR00.45-Z-1102-06A
7	Check ignition coils (T1/1, T1/2, T1/3 and T1/4) and spark plug connectors (a) for damage	If a problem arises ↓ Replace corresponding components.
8	Install in the reverse order
	Check
9	Connect diagnostic system; read out fault memory.	Only if required.
			AD00.00-P-2000-04B
	Risk of burn injuries  , suffocation and poisoning when working on the exhaust system and the components connected to it. Risk of suffocation and risk of poisoning caused by inhalation of gaseous and solid components of the exhaust. Risk of poisoning  caused by skin contact with solid components of the exhaust.	Wear protective clothing and safety glasses. Use the extraction system. Move people out of the hazard area.	AS49.00-Z-0001-01A
	Risk of accident  from vehicle starting off by itself when engine running. Risk of injury  (bruises and burns) resulting from working on the engine while it is being started or when it is running.	Secure vehicle to prevent it from starting off by itself. Wear closed and snug-fitting work clothes. Do not touch hot or rotating parts.	AS00.00-Z-0005-01A
10	Conduct engine test run while checking for proper operation of the engine