Ignition Control Module: Description and Operation

PURPOSE
The Ignition ECM converts analog inputs into digital outputs and controls all aspects of ignition timing. Timing calculations are implemented through ECM control of two power modules. By regulating these switching devices, the ECM determines when spark plug firing occurs.

Ignition Control:

OPERATION
The ECM contains a microprocessor that is programmed with an ignition timing strategy providing precision choices for every engine speed and mode of operation. The ECM also receives input signals from:

^ Air Temperature Sensor
^ Coolant Temperature Sensor
^ Engine Speed Sensor
^ Idle switch
^ TDC Sensor
^ Transmission ECU request for retard.

None of the sensors are shared with EFI ECM.

Ignition ECM sends engine speed signals to EFI ECM, tachometer, transmission ECU, and fuel pump control module.

CONSTRUCTION
ECU is a computer with programmed microprocessor. The MAP sensor, providing engine load information, is an internal component.

Control Module Locations And I.D.:

LOCATION
In front passenger footwell.

Ignition ECM Pin Out:

PIN CONNECTIONS