Subaru Coupes/Sedans/Wagons 1985-1996 Repair Guide

General Information


See Figure 1

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Fig. Fig. 1: Direct ignition system-SVX models

A direct ignition system is used on all SVX models. The system consists of crank and camshaft angle sensors, two knock sensors, an igniter, six ignition coils, an electronic control unit (ECU) and assorted sensors.

The ignition coils are directly mounted to the spark plugs of the respective cylinders. This results in a reduced energy loss because no high tension wires are used.

The ignition system is controlled by the Electronic Control Unit (ECU). The ECU determines the ignition timing based on the signal from crank angle sensor 1, and sends the signal to the igniter to spark the cylinder which is judged to be at top dead center of the compression stroke by crank angle sensor 2 and the camshaft angle sensor. When engine speed is low, the ECU fixes the timing at 10° BTDC.

One knock sensor is install on the left cylinder block and another on the right cylinder block, thus ensuring accurate digital engine knock control.