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

Engine 157, 278 in model 166 

Engine 157, 278 in model 292 

Shown on left cylinder head on engine 157 

Fig 1: Ignition Coils Components Location - Engine 157, 278 In Model 166 (Shown On Left Cylinder Head On Engine 157)

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
	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 covers
3	Remove air filter housing (2) with respective engine air intake duct
4	Remove insulation of the left and right rail
5	Release and disconnect electrical connections (3) from ignition coils (T1/1, T1/2, T1/3, T1/4, T1/5, T1/6, T1/7 and T1/8)
6	Remove screws/bolts (5)	Screw/bolt, ignition coil to cylinder head cover	*BA15.10-P-1001-04A
7	Pull off and remove the ignition coils (T1/1, T1/2, T1/3, T1/4, T1/5, T1/6, T1/7 and T1/8) including spark plug connectors	Apply spark plug connector grease prior to installing the spark plug connector to reduce the force required for connection and disconnection. Otherwise the spark plug connector will be damaged when removed again. Discharge approx. Fill 1 g of spark plug connector grease into the spark plug connector.
		Spark plug connector grease	*BR00.45-Z-1102-06A
8	Check the ignition coils (T1/1, T1/2, T1/3, T1/4, T1/5, T1/6, T1/7 and T1/8) and spark plug connectors (a) for damage and replace if necessary
9	Install in the reverse order
	Check
10	Connect diagnostic system; read out fault memory.	Only if required.
			AD00.00-P-2000-04A
	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 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
11	Conduct engine test run while checking for proper operation of the engine