Ignition System, Basic Function - GF07.10-P-1035A

Engine 139, 176, 177, 254, 256, 260, 264, 274, 279, 282 

Example illustration of the cylinder arrangement and firing order 

Courtesy of MERCEDES-BENZ USA

Overview 

This document contains information on:

• General 
• Function requirements 
• Function 
  • Single spark ignition 
  • Multi-spark ignition 

General 

The ignition system initiates the ignition of the fuel/air mixture in spark-ignition engines through a high-voltage ignition spark. With this, it contributes substantially to the generation of the specific engine output and influences the combustion emissions as well as engine torque and the exhaust gas temperature.

Function requirements 

• Engine management ON (circuit 87M)

Function 

Single spark ignition 

Ignition coils are charged once per ignition process and an ignition spark is generated. Single-spark ignition is characterized by a long charging time for the ignition coils.

Multi-spark ignition 

To ignite the fuel/air mixture optimally, even under critical conditions (e.g. high flow rates), the multi-spark ignition is used.

After compression of the fuel/air mixture and supercharging by the respective ignition coil, a spark plug generates up to four ignition sparks at defined intervals for multi-spark ignition.

As a result, efficient combustion of the fuel/air mixture is achieved, the fuel consumption is reduced correspondingly and an optimized output of the combustion engine is generated. Between the ignition sparks, the ignition coils do not discharge completely.

When the charging current is interrupted at the firing point, an ignition spark is produced. In order to reduce the charging time until the next spark, energy is stored for the next ignition spark through intermediate charging.

Example illustration of multi-spark ignition (ideal primary and secondary current curve) 

Courtesy of MERCEDES-BENZ USA

	Function schematics
	Function schematic for ignition system	Engine 282 in model 118, 177, 247	PE15.10-P-2500-97A
		Engine 260 in model 118, 177, 247 Engine 264 in model 167	PE15.10-P-2500-97B
		Engine 256 in model 167 Engine 264 in model 213, 238, 257 as of model year 2021	PE15.10-P-2500-97C
		Engine 176, 177 in model 167 Engine 177 in model 290 as of model year 2021	PE15.10-P-2500-97D
		Engine 139 in model 118, 177, 247	PE15.10-P-2500-97E
		Engine 254 in model 206, 214, 236, 254 Engine 256 in model 214, 223, 236	PE15.10-P-2500-97F
		Engine 176 in model 223	PE15.10-P-2500-97G
		Engine 279 in model 223	PE15.10-P-2500-97H
		Engine 139 in model 192, 206, 232, 236, 254	PE15.10-P-2500-97I
		Engine 177 in model 192, 223, 232	PE15.10-P-2500-97J
		Engine 274 in model 213 as of model year 2021	PE15.10-P-2500-97K
	Additional basic functions
	Ignition angle setting, basic function		GF07.10-P-1046A
	Ignition coils, basic function		GF15.10-P-2002A