Ignition System: Description and Operation

EZL/AKR Control Unit For Left Cylinder Bank:

LEFT CYLINDER BANK

EZL/AKR Control Unit For Right Cylinder Bank:

RIGHT CYLINDER BANK

PURPOSE
The Bosch EZL/AKR ignition system delivers a precisely timed, high energy spark to the combustion chamber to ensure efficient combustion, optimum performance, and strict emissions compliance. The high tension ignition system delivers sufficient energy to ignite the air/fuel mixture under all normal operating conditions.

DESIGN
This EZL/AKR ignition control system uses two separate control systems. One for the left cylinder bank and one for the right cylinder bank.

COMPONENTS
The EZL/AKR computerized ignition system consists of two EZL/AKR control units (N1/4 and N1/5), two ignition coils (T1/1 and T1/2), two high-tension distributors, ignition wires with suppression connectors and spark plugs (R4).

OPERATION
The primary side of the coil is connected with the positive battery terminal via the ignition switch. During the primary current-flow time (coil saturation) the coil is connected to ground through the power output transistor of the EZL/AKR control unit. The control unit receives input signals from the ignition switch, crankshaft position sensor, reference resistor, intake manifold vacuum signal, coolant temperature sensor, camshaft position sensor, knock sensors, transmission overload protection switch, and information from the other control units (via the CAN); processes these signals, and calculates the appropriate dwell/ignition angle, and simultaneously switches the ignition coil ground circuit. For more information on electronic controls for the ignition system, see COMPUTER AND CONTROL SYSTEMS.