LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Saab >> 2004 >> 9-3 Linear, Automatic >> Repair and Diagnosis >> Electrical >> Body Electrical >> Control Module >> Technical Description >> Ionization Detection Module (740) >> Main task
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Main task

The CDM does an initial signal processing of the ionization signals from each ignition coil. The CDM transmits three signals to the ECM:

These signals are used for knock control, synchronization of ignition timing/fuel injection and for misfire detection.