Mazda RX-8 2004 Service Highlights page 345

ON-BOARD DIAGNOSTIC SYSTEM FUNCTION (ELECTRIC POWER STEERING)
Malfunction Detection Function
• The malfunction detection function detects malfunctions in the input/output signal system of the EPS control
module when the ignition switch is at the ON position or driving the vehicle.
• When the ignition switch is turned to the ON position, the EPS warning light illuminates as shown in the
diagram to inspect for open circuits in the light.
WHEN THE PERIOD UNTIL ENGINE ROTATION
IS DETERMINED IS 2.4±0.2 S OR LESS
IGNITION
SWITCH
ENGINE
ROTATION
DETERMINED
WHEN THE PERIOD UNTIL ENGINE ROTATION
IS DETERMINED IS 2.4±0.2 S OR MORE
IGNITION
SWITCH
ENGINE
ROTATION
DETERMINED
Malfunction Display Function
• When the malfunction detection function detects a malfunction, the EPS warning light illuminates to advise the
driver. Using the external tester communication function, DTCs can be output to the DLC-2 via the CAN
communication line. At the same time, malfunction detection results are sent to the memory and fail-safe
functions.
Memory Function
• The memory function stores DTCs for malfunctions in input/output signal systems. With this function, once a
DTC is stored it is not cleared after the ignition switch has been turned off (LOCK position), even if the
malfunctioning signal system has returned to normal.
• Since the EPS control module has a built-in non-volatile memory, DTCs are not cleared even if the battery is
removed. Therefore, it is necessary to clear the memory after performing repairs. Refer to the Workshop
Manual for the DTC clearing procedure.
Fail-safe Function
• When the malfunction detection function determines a malfunction, the EPS warning light illuminates to advise
the driver. At this time, the fail-safe function controls the system as shown in the DTC table.
06–02–2
ON-BOARD DIAGNOSTIC
ON
OFF
ENGINE
ROTATING
ENGINE
STOPPED
250 ms
ON
OFF
ENGINE
ROTATING
ENGINE
STOPPED
TIME UNTIL ENGINE
IS DETERMINED
250 ms
TO BE ROTATING
2.4±0.2 s OR LESS
2.4±0.2 s
CHU060201038S02
CHU0602S100