Ignition Timing Control - Rotary and Stationary

- Basic triggering of the output (primary of/off) is based on inputs of engine speed and the position of the crankshaft.
- The reference position signal (one pulse per rotation) establishes the TDC position of the crankshaft by the ECM.
- The engine speed signal is then used to determine the exact position of each cylinder for timing control.
- The ignition timing can then be updated between individual spark plug firings as needed.

This is the basis for all Bosch stationary and rotary systems.

Additional correction factors influence ignition as follows.

ADDITIONAL PROGRAMMING CONTROLS

IGNITION TIMING RETARD:
To reduce engine torque; signal request from:
- EGS/AGS
- ASC

IGNITION TIMING "ADVANCE":
To reduce the affect of "engine braking"; signal request from ASO.

IGNITION TIMING "FADE OUT":
To sharply reduce engine torque, signal request from ASC.

IGNITION (Trigger) "CANCEL":
To prevent engine startup, signal request from;
- "Start Interlock" of QBC/DWA,
- Driveaway Protection Circuit
- EWS I (Starter Immobilizer Relay)

MAXIMUM VEHICLE SPEED:
To limit maximum vehicle speed