9-3 XWD (9440) L4-2.0L Turbo (B207R) (2009)
Ignition Control Module: Description and Operation
Ionization Detection Module (740)
Ionization Detection Module (740)
Location
Ionization Detection Module (740)
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:
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Knock signal
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Combustion signal 1 (cylinders 1 and 3)
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Combustion signal 2 (cylinders 2 and 4)
These signals are used for knock control, synchronisation of ignition timing/fuel injection and for misfire detection.
Type
The digital unit which does an initial processing of the ionization signals.
NOTE: The CDM incorporates digital signal processing. It can not be used on vehicles of an earlier model year because they use analogue signal
processing. In order to prevent any interchanging, the connectors are different.
Connection