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

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

Overview

This document contains information

General
Function requirements
Function

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)

Engine configuration and ignition firing order

Courtesy of MERCEDES-BENZ USA

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 the compression of the fuel/air mixture and supercharging by the respective ignition coil, a spark plug generates up to four ignition sparks at distances defined at time 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.

Ideal development of the primary and secondary current for a multi-spark ignition

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 256 in Model 213, 238 as of model year 2021 Engine 264 in Model 213, 238, 257 as of model year 2021	PE15.10-P-2500-97C
	Engine 176, 177 in Model 167 Engine 177.8 in Model 290	PE15.10-P-2500-97D
	Engine 139 in Model 118, 177, 247	PE15.10-P-2500-97E
	Engine 254 in Model 206 Engine 256 in Model 223	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 177.8 in Model 223, 232	PE15.10-P-2500-97J
Additional basic functions
Ignition angle setting, basic function	Engine 139, 176, 177, 254, 256, 260, 264, 279, 282	GF07.10-P-1046A
Ignition coils, basic function	Engine 139, 176, 177, 254, 256, 260, 264, 279, 282	GF15.10-P-2002A