Subaru XT 1988 Service Manual page 852

4-3
STEERING SYSTEM
Tilt steering ASSY
Hose ASSY
Steering gearbox ASSY
Fig. 5
Electronic Control Logic Configuration
The electronic control logic configuration of the electronic-
controlled motor drive power steering system included both an
initial diagnostic function and a normal processing function to
monitor input and output signals transmitted by various parts.
It includes a self-diagnosis function by which warning lamps
are activated to indicate a problem. It also has a self-check
function. Malfunctioning systems can be determined by the
operation (blinking) of the warning lamp in the "check"
mode.
Operation (blinking) of warning
lamp is read to determine
a malfunctioning system.
Constant monitor
of system operation
6
Motor pump
Power controller
Steering sensor
L4-1402
1) Initial diagnosis
In the initial diagnosis mode, current flowing through the
warning lamp system, engine signal system and electric motor
system is checked.
Ignition switch ON
Checking warning lamp for operation
Start the engine
Checking engine input signals,
and operation of motor and controller
Warning lamp
comes on
Warning lamp
does not come on
Normal processing
is conducted