Operation

OPERATION
The EZL/AKR control modules receive information concerning:

^ Voltage supply (+)
^ Engine speed from crankshaft position sensors (L5/4 or L5/5)
^ Cylinder #12 position from camshaft position sensors (L5/2 or L5/3)
^ Engine load condition from intake manifold vacuum signal
^ Selection of ignition map from EZL/AKR reference resistors (R16/3 or R16/4)
^ Shift preconditions from transmission overload protection switches, brake band B1 (S65) and B2 (S65/1)
^ Combustion knock from two knock sensors (A29 or A30)
^ Fuel injection information from LH control modules (N3/2 or N3/3)
^ Throttle position from Electronic accelerator control module (N4/1)
^ ABS/ASR information from ABS/ASR control module (N30/1)

The EZL/AKR control modules compare information from these inputs with ignition maps for typical load and speed ranges which are stored in the microcomputer. The optimal ignition timing for each operating condition is instantaneously determined from the stored maps and the power output stage switches the primary current of the ignition coil.

Furthermore, a TD (engine speed) reference signal is provided to the LH control module, tachometer, on-board diagnostic connector, and the diagnostic socket. To further increase operating reliability, a data exchange circuit has been added between the EZL/AKR control modules and the LH control modules. Information concerning the coolant temperature, intake air temperature and the intake manifold absolute pressure is continuously compared by the control module of each system.

During cranking and up to approx. 450 RPM, the ignition timing is controlled via the segment edges (fixed) of the flywheel. After approx. 460 RPM has been attained a transition from the fixed ignition timing to dynamic ignition timing (instantaneous, ignition map comparison) is made. Various ignition characteristic curves are inhibited in the warm-up range depending on the coolant temperature in order to reach the normal operating temperature as rapidly as possible.

When a full load signal is received from the electronic accelerator control module (N4/1), the EZL/AKR control module adapts a fixed full load ignition map characteristic. At temperatures above approx. 203°F the ignition will be retarded to counter any further rise in temperature.