Ignition System: Description and Operation

Ignition System And Components:

IGNITION SYSTEM (BOSCH EZ117K):

BOSCH EZ117K stands for:

BOSCH = manufacturer
E = elektronische (German for electronic)
Z = zuendung (German for ignition)
117 = model series
K = klopfregelung (German for knock control)

This ignition is based on the fully electronically controlled Bosch hall-effect ignition system with knock control (EZ-K). The ECU uses electrical input signals from various devices and sensors to calculate the engine load and condition. With this information the ECU will adjust the ignition timing to provide optimal performance, driveability and emissions output.

Input devices (the ECU receives):

^ Ignition switch signal.
^ Crankshaft position and speed (hall-effect) signal.
^ Knock signal.
^ Air mass meter signal from fuel injection control unit.
^ Throttle position signal.
^ A/C control signal from climate control panel.
^ A/C pressure sensor signal.

Output devices (The ECU controls):

^ Power stage.
^ Engine speed (RPM) signal to the fuel injection control unit (fuel injection ECU input device).
^ Knock signal to the fuel injection control unit (fuel injection ECU input device).
^ Crankshaft position and speed (hall-effect) sensor power supply (12V).