Remove/install ignition coils - AR15.12-P-2003MRE

ENGINE 274 in MODEL 172 

Fig 1: Identifying Ignition Coils Remove/Install Components

Courtesy of MERCEDES-BENZ USA

	Remove/install
1	Remove upper engine cover
2	Unclip coolant vent line (4) on bracket	Engine 274 in model 172 except code 494 (US version) When removing the ignition coil for cylinder 1 (T1/1)
3	Remove screw/bolt (3)	Screw/bolt, ignition coil to cylinder head cover	*BA15.10-P-1001-04A
4	Disconnect electrical connection on ignition coils (T1/1 to T1/4)
5	Detach ignition coils (T1/1 up to T1/4) with spark plug connectors (a) upwards and remove
	Check
6	Check ignition coils (T1/1 up to T1/4) and spark plug connectors (a) for damage and replace if necessary	The ignition coils (T1/1 to T1/4) and the spark plug connector (a) create a unit and can therefore only be removed and replaced together.
7	Install in the reverse order
8	Read out fault memory using the diagnostic system and clear if necessary
	Connect STAR DIAGNOSIS and read out fault memory		AD00.00-P-2000-04A

IGNITION COIL

Number	Designation		Engine 274
BA15.10-P-1001-04A	Screw/bolt, ignition coil to cylinder head cover	Nm	9